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Section mismatch with extra_latent_entropy in v5.1 #7

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tsautereau-anssi opened this issue May 7, 2019 · 1 comment
Closed

Section mismatch with extra_latent_entropy in v5.1 #7

tsautereau-anssi opened this issue May 7, 2019 · 1 comment

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@tsautereau-anssi
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extra_latent_entropy is marked __meminitdata. Following commit a9cd410a3d29 ("mm/page_alloc.c: memory hotplug: free pages as higher order") in v5.1, static void __init __free_pages_boot_core() was changed into void __free_pages_core(), causing the following section mismatch warning at compile time:

WARNING: vmlinux.o(.text+0x180fe4): Section mismatch in reference from the function __free_pages_core() to the variable .meminit.data:extra_latent_entropy
The function __free_pages_core() references
the variable __meminitdata extra_latent_entropy.
This is often because __free_pages_core lacks a __meminitdata
annotation or the annotation of extra_latent_entropy is wrong.
anthraxx pushed a commit that referenced this issue May 20, 2019
[ Upstream commit b9abbdf ]

By calling maps__insert() we assume to get 2 references on the map,
which we relese within maps__remove call.

However if there's already same map name, we currently don't bump the
reference and can crash, like:

  Program received signal SIGABRT, Aborted.
  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6

  (gdb) bt
  #0  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6
  #1  0x00007ffff75d0895 in abort () from /lib64/libc.so.6
  #2  0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/libc.so.6
  #3  0x00007ffff75de596 in __assert_fail () from /lib64/libc.so.6
  #4  0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131
  #5  refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148
  #6  map__put (map=0x1224df0) at util/map.c:299
  #7  0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953
  #8  maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959
  #9  0x00000000004f7d8a in map_groups__remove (map=<optimized out>, mg=<optimized out>) at util/map_groups.h:65
  #10 machine__process_ksymbol_unregister (sample=<optimized out>, event=0x7ffff7279670, machine=<optimized out>) at util/machine.c:728
  #11 machine__process_ksymbol (machine=<optimized out>, event=0x7ffff7279670, sample=<optimized out>) at util/machine.c:741
  #12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362
  #13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243
  #14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=<optimized out>) at util/ordered-events.c:322
  #15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8,
  ...

Add the map to the list and getting the reference event if we find the
map with same name.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Fixes: 1e62856 ("perf symbols: Fix slowness due to -ffunction-section")
Link: http://lkml.kernel.org/r/20190416160127.30203-10-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jun 2, 2019
[ Upstream commit ff612ba ]

We've been seeing the following sporadically throughout our fleet

panic: kernel BUG at fs/btrfs/relocation.c:4584!
netversion: 5.0-0
Backtrace:
 #0 [ffffc90003adb880] machine_kexec at ffffffff81041da8
 #1 [ffffc90003adb8c8] __crash_kexec at ffffffff8110396c
 #2 [ffffc90003adb988] crash_kexec at ffffffff811048ad
 #3 [ffffc90003adb9a0] oops_end at ffffffff8101c19a
 #4 [ffffc90003adb9c0] do_trap at ffffffff81019114
 #5 [ffffc90003adba00] do_error_trap at ffffffff810195d0
 #6 [ffffc90003adbab0] invalid_op at ffffffff81a00a9b
    [exception RIP: btrfs_reloc_cow_block+692]
    RIP: ffffffff8143b614  RSP: ffffc90003adbb68  RFLAGS: 00010246
    RAX: fffffffffffffff7  RBX: ffff8806b9c32000  RCX: ffff8806aad00690
    RDX: ffff880850b295e0  RSI: ffff8806b9c32000  RDI: ffff88084f205bd0
    RBP: ffff880849415000   R8: ffffc90003adbbe0   R9: ffff88085ac90000
    R10: ffff8805f7369140  R11: 0000000000000000  R12: ffff880850b295e0
    R13: ffff88084f205bd0  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffc90003adbbb0] __btrfs_cow_block at ffffffff813bf1cd
 #8 [ffffc90003adbc28] btrfs_cow_block at ffffffff813bf4b3
 #9 [ffffc90003adbc78] btrfs_search_slot at ffffffff813c2e6c

The way relocation moves data extents is by creating a reloc inode and
preallocating extents in this inode and then copying the data into these
preallocated extents.  Once we've done this for all of our extents,
we'll write out these dirty pages, which marks the extent written, and
goes into btrfs_reloc_cow_block().  From here we get our current
reloc_control, which _should_ match the reloc_control for the current
block group we're relocating.

However if we get an ENOSPC in this path at some point we'll bail out,
never initiating writeback on this inode.  Not a huge deal, unless we
happen to be doing relocation on a different block group, and this block
group is now rc->stage == UPDATE_DATA_PTRS.  This trips the BUG_ON() in
btrfs_reloc_cow_block(), because we expect to be done modifying the data
inode.  We are in fact done modifying the metadata for the data inode
we're currently using, but not the one from the failed block group, and
thus we BUG_ON().

(This happens when writeback finishes for extents from the previous
group, when we are at btrfs_finish_ordered_io() which updates the data
reloc tree (inode item, drops/adds extent items, etc).)

Fix this by writing out the reloc data inode always, and then breaking
out of the loop after that point to keep from tripping this BUG_ON()
later.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ add note from Filipe ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jun 2, 2019
[ Upstream commit f80c5da ]

This commit makes the kernel not send the next queued HCI command until
a command complete arrives for the last HCI command sent to the
controller. This change avoids a problem with some buggy controllers
(seen on two SKUs of QCA9377) that send an extra command complete event
for the previous command after the kernel had already sent a new HCI
command to the controller.

The problem was reproduced when starting an active scanning procedure,
where an extra command complete event arrives for the LE_SET_RANDOM_ADDR
command. When this happends the kernel ends up not processing the
command complete for the following commmand, LE_SET_SCAN_PARAM, and
ultimately behaving as if a passive scanning procedure was being
performed, when in fact controller is performing an active scanning
procedure. This makes it impossible to discover BLE devices as no device
found events are sent to userspace.

This problem is reproducible on 100% of the attempts on the affected
controllers. The extra command complete event can be seen at timestamp
27.420131 on the btmon logs bellow.

Bluetooth monitor ver 5.50
= Note: Linux version 5.0.0+ (x86_64)                                  0.352340
= Note: Bluetooth subsystem version 2.22                               0.352343
= New Index: 80:C5:F2:8F:87:84 (Primary,USB,hci0)               [hci0] 0.352344
= Open Index: 80:C5:F2:8F:87:84                                 [hci0] 0.352345
= Index Info: 80:C5:F2:8F:87:84 (Qualcomm)                      [hci0] 0.352346
@ MGMT Open: bluetoothd (privileged) version 1.14             {0x0001} 0.352347
@ MGMT Open: btmon (privileged) version 1.14                  {0x0002} 0.352366
@ MGMT Open: btmgmt (privileged) version 1.14                {0x0003} 27.302164
@ MGMT Command: Start Discovery (0x0023) plen 1       {0x0003} [hci0] 27.302310
        Address type: 0x06
          LE Public
          LE Random
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6   #1 [hci0] 27.302496
        Address: 15:60:F2:91:B2:24 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4                 #2 [hci0] 27.419117
      LE Set Random Address (0x08|0x0005) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7  #3 [hci0] 27.419244
        Type: Active (0x01)
        Interval: 11.250 msec (0x0012)
        Window: 11.250 msec (0x0012)
        Own address type: Random (0x01)
        Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4                 #4 [hci0] 27.420131
      LE Set Random Address (0x08|0x0005) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2      #5 [hci0] 27.420259
        Scanning: Enabled (0x01)
        Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4                 #6 [hci0] 27.420969
      LE Set Scan Parameters (0x08|0x000b) ncmd 1
        Status: Success (0x00)
> HCI Event: Command Complete (0x0e) plen 4                 #7 [hci0] 27.421983
      LE Set Scan Enable (0x08|0x000c) ncmd 1
        Status: Success (0x00)
@ MGMT Event: Command Complete (0x0001) plen 4        {0x0003} [hci0] 27.422059
      Start Discovery (0x0023) plen 1
        Status: Success (0x00)
        Address type: 0x06
          LE Public
          LE Random
@ MGMT Event: Discovering (0x0013) plen 2             {0x0003} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)
@ MGMT Event: Discovering (0x0013) plen 2             {0x0002} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)
@ MGMT Event: Discovering (0x0013) plen 2             {0x0001} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jun 2, 2019
[ Upstream commit ff612ba ]

We've been seeing the following sporadically throughout our fleet

panic: kernel BUG at fs/btrfs/relocation.c:4584!
netversion: 5.0-0
Backtrace:
 #0 [ffffc90003adb880] machine_kexec at ffffffff81041da8
 #1 [ffffc90003adb8c8] __crash_kexec at ffffffff8110396c
 #2 [ffffc90003adb988] crash_kexec at ffffffff811048ad
 #3 [ffffc90003adb9a0] oops_end at ffffffff8101c19a
 #4 [ffffc90003adb9c0] do_trap at ffffffff81019114
 #5 [ffffc90003adba00] do_error_trap at ffffffff810195d0
 #6 [ffffc90003adbab0] invalid_op at ffffffff81a00a9b
    [exception RIP: btrfs_reloc_cow_block+692]
    RIP: ffffffff8143b614  RSP: ffffc90003adbb68  RFLAGS: 00010246
    RAX: fffffffffffffff7  RBX: ffff8806b9c32000  RCX: ffff8806aad00690
    RDX: ffff880850b295e0  RSI: ffff8806b9c32000  RDI: ffff88084f205bd0
    RBP: ffff880849415000   R8: ffffc90003adbbe0   R9: ffff88085ac90000
    R10: ffff8805f7369140  R11: 0000000000000000  R12: ffff880850b295e0
    R13: ffff88084f205bd0  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffc90003adbbb0] __btrfs_cow_block at ffffffff813bf1cd
 #8 [ffffc90003adbc28] btrfs_cow_block at ffffffff813bf4b3
 #9 [ffffc90003adbc78] btrfs_search_slot at ffffffff813c2e6c

The way relocation moves data extents is by creating a reloc inode and
preallocating extents in this inode and then copying the data into these
preallocated extents.  Once we've done this for all of our extents,
we'll write out these dirty pages, which marks the extent written, and
goes into btrfs_reloc_cow_block().  From here we get our current
reloc_control, which _should_ match the reloc_control for the current
block group we're relocating.

However if we get an ENOSPC in this path at some point we'll bail out,
never initiating writeback on this inode.  Not a huge deal, unless we
happen to be doing relocation on a different block group, and this block
group is now rc->stage == UPDATE_DATA_PTRS.  This trips the BUG_ON() in
btrfs_reloc_cow_block(), because we expect to be done modifying the data
inode.  We are in fact done modifying the metadata for the data inode
we're currently using, but not the one from the failed block group, and
thus we BUG_ON().

(This happens when writeback finishes for extents from the previous
group, when we are at btrfs_finish_ordered_io() which updates the data
reloc tree (inode item, drops/adds extent items, etc).)

Fix this by writing out the reloc data inode always, and then breaking
out of the loop after that point to keep from tripping this BUG_ON()
later.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ add note from Filipe ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jun 2, 2019
[ Upstream commit f80c5da ]

This commit makes the kernel not send the next queued HCI command until
a command complete arrives for the last HCI command sent to the
controller. This change avoids a problem with some buggy controllers
(seen on two SKUs of QCA9377) that send an extra command complete event
for the previous command after the kernel had already sent a new HCI
command to the controller.

The problem was reproduced when starting an active scanning procedure,
where an extra command complete event arrives for the LE_SET_RANDOM_ADDR
command. When this happends the kernel ends up not processing the
command complete for the following commmand, LE_SET_SCAN_PARAM, and
ultimately behaving as if a passive scanning procedure was being
performed, when in fact controller is performing an active scanning
procedure. This makes it impossible to discover BLE devices as no device
found events are sent to userspace.

This problem is reproducible on 100% of the attempts on the affected
controllers. The extra command complete event can be seen at timestamp
27.420131 on the btmon logs bellow.

Bluetooth monitor ver 5.50
= Note: Linux version 5.0.0+ (x86_64)                                  0.352340
= Note: Bluetooth subsystem version 2.22                               0.352343
= New Index: 80:C5:F2:8F:87:84 (Primary,USB,hci0)               [hci0] 0.352344
= Open Index: 80:C5:F2:8F:87:84                                 [hci0] 0.352345
= Index Info: 80:C5:F2:8F:87:84 (Qualcomm)                      [hci0] 0.352346
@ MGMT Open: bluetoothd (privileged) version 1.14             {0x0001} 0.352347
@ MGMT Open: btmon (privileged) version 1.14                  {0x0002} 0.352366
@ MGMT Open: btmgmt (privileged) version 1.14                {0x0003} 27.302164
@ MGMT Command: Start Discovery (0x0023) plen 1       {0x0003} [hci0] 27.302310
        Address type: 0x06
          LE Public
          LE Random
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6   #1 [hci0] 27.302496
        Address: 15:60:F2:91:B2:24 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4                 #2 [hci0] 27.419117
      LE Set Random Address (0x08|0x0005) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7  #3 [hci0] 27.419244
        Type: Active (0x01)
        Interval: 11.250 msec (0x0012)
        Window: 11.250 msec (0x0012)
        Own address type: Random (0x01)
        Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4                 #4 [hci0] 27.420131
      LE Set Random Address (0x08|0x0005) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2      #5 [hci0] 27.420259
        Scanning: Enabled (0x01)
        Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4                 #6 [hci0] 27.420969
      LE Set Scan Parameters (0x08|0x000b) ncmd 1
        Status: Success (0x00)
> HCI Event: Command Complete (0x0e) plen 4                 #7 [hci0] 27.421983
      LE Set Scan Enable (0x08|0x000c) ncmd 1
        Status: Success (0x00)
@ MGMT Event: Command Complete (0x0001) plen 4        {0x0003} [hci0] 27.422059
      Start Discovery (0x0023) plen 1
        Status: Success (0x00)
        Address type: 0x06
          LE Public
          LE Random
@ MGMT Event: Discovering (0x0013) plen 2             {0x0003} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)
@ MGMT Event: Discovering (0x0013) plen 2             {0x0002} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)
@ MGMT Event: Discovering (0x0013) plen 2             {0x0001} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jun 2, 2019
[ Upstream commit ff612ba ]

We've been seeing the following sporadically throughout our fleet

panic: kernel BUG at fs/btrfs/relocation.c:4584!
netversion: 5.0-0
Backtrace:
 #0 [ffffc90003adb880] machine_kexec at ffffffff81041da8
 #1 [ffffc90003adb8c8] __crash_kexec at ffffffff8110396c
 #2 [ffffc90003adb988] crash_kexec at ffffffff811048ad
 #3 [ffffc90003adb9a0] oops_end at ffffffff8101c19a
 #4 [ffffc90003adb9c0] do_trap at ffffffff81019114
 #5 [ffffc90003adba00] do_error_trap at ffffffff810195d0
 #6 [ffffc90003adbab0] invalid_op at ffffffff81a00a9b
    [exception RIP: btrfs_reloc_cow_block+692]
    RIP: ffffffff8143b614  RSP: ffffc90003adbb68  RFLAGS: 00010246
    RAX: fffffffffffffff7  RBX: ffff8806b9c32000  RCX: ffff8806aad00690
    RDX: ffff880850b295e0  RSI: ffff8806b9c32000  RDI: ffff88084f205bd0
    RBP: ffff880849415000   R8: ffffc90003adbbe0   R9: ffff88085ac90000
    R10: ffff8805f7369140  R11: 0000000000000000  R12: ffff880850b295e0
    R13: ffff88084f205bd0  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffc90003adbbb0] __btrfs_cow_block at ffffffff813bf1cd
 #8 [ffffc90003adbc28] btrfs_cow_block at ffffffff813bf4b3
 #9 [ffffc90003adbc78] btrfs_search_slot at ffffffff813c2e6c

The way relocation moves data extents is by creating a reloc inode and
preallocating extents in this inode and then copying the data into these
preallocated extents.  Once we've done this for all of our extents,
we'll write out these dirty pages, which marks the extent written, and
goes into btrfs_reloc_cow_block().  From here we get our current
reloc_control, which _should_ match the reloc_control for the current
block group we're relocating.

However if we get an ENOSPC in this path at some point we'll bail out,
never initiating writeback on this inode.  Not a huge deal, unless we
happen to be doing relocation on a different block group, and this block
group is now rc->stage == UPDATE_DATA_PTRS.  This trips the BUG_ON() in
btrfs_reloc_cow_block(), because we expect to be done modifying the data
inode.  We are in fact done modifying the metadata for the data inode
we're currently using, but not the one from the failed block group, and
thus we BUG_ON().

(This happens when writeback finishes for extents from the previous
group, when we are at btrfs_finish_ordered_io() which updates the data
reloc tree (inode item, drops/adds extent items, etc).)

Fix this by writing out the reloc data inode always, and then breaking
out of the loop after that point to keep from tripping this BUG_ON()
later.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ add note from Filipe ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
awcurless pushed a commit to awcurless/linux-hardened that referenced this issue Jun 4, 2019
[ Upstream commit f80c5da ]

This commit makes the kernel not send the next queued HCI command until
a command complete arrives for the last HCI command sent to the
controller. This change avoids a problem with some buggy controllers
(seen on two SKUs of QCA9377) that send an extra command complete event
for the previous command after the kernel had already sent a new HCI
command to the controller.

The problem was reproduced when starting an active scanning procedure,
where an extra command complete event arrives for the LE_SET_RANDOM_ADDR
command. When this happends the kernel ends up not processing the
command complete for the following commmand, LE_SET_SCAN_PARAM, and
ultimately behaving as if a passive scanning procedure was being
performed, when in fact controller is performing an active scanning
procedure. This makes it impossible to discover BLE devices as no device
found events are sent to userspace.

This problem is reproducible on 100% of the attempts on the affected
controllers. The extra command complete event can be seen at timestamp
27.420131 on the btmon logs bellow.

Bluetooth monitor ver 5.50
= Note: Linux version 5.0.0+ (x86_64)                                  0.352340
= Note: Bluetooth subsystem version 2.22                               0.352343
= New Index: 80:C5:F2:8F:87:84 (Primary,USB,hci0)               [hci0] 0.352344
= Open Index: 80:C5:F2:8F:87:84                                 [hci0] 0.352345
= Index Info: 80:C5:F2:8F:87:84 (Qualcomm)                      [hci0] 0.352346
@ MGMT Open: bluetoothd (privileged) version 1.14             {0x0001} 0.352347
@ MGMT Open: btmon (privileged) version 1.14                  {0x0002} 0.352366
@ MGMT Open: btmgmt (privileged) version 1.14                {0x0003} 27.302164
@ MGMT Command: Start Discovery (0x0023) plen 1       {0x0003} [hci0] 27.302310
        Address type: 0x06
          LE Public
          LE Random
< HCI Command: LE Set Random Address (0x08|0x0005) plen 6   anthraxx#1 [hci0] 27.302496
        Address: 15:60:F2:91:B2:24 (Non-Resolvable)
> HCI Event: Command Complete (0x0e) plen 4                 anthraxx#2 [hci0] 27.419117
      LE Set Random Address (0x08|0x0005) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7  anthraxx#3 [hci0] 27.419244
        Type: Active (0x01)
        Interval: 11.250 msec (0x0012)
        Window: 11.250 msec (0x0012)
        Own address type: Random (0x01)
        Filter policy: Accept all advertisement (0x00)
> HCI Event: Command Complete (0x0e) plen 4                 anthraxx#4 [hci0] 27.420131
      LE Set Random Address (0x08|0x0005) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2      anthraxx#5 [hci0] 27.420259
        Scanning: Enabled (0x01)
        Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4                 anthraxx#6 [hci0] 27.420969
      LE Set Scan Parameters (0x08|0x000b) ncmd 1
        Status: Success (0x00)
> HCI Event: Command Complete (0x0e) plen 4                 anthraxx#7 [hci0] 27.421983
      LE Set Scan Enable (0x08|0x000c) ncmd 1
        Status: Success (0x00)
@ MGMT Event: Command Complete (0x0001) plen 4        {0x0003} [hci0] 27.422059
      Start Discovery (0x0023) plen 1
        Status: Success (0x00)
        Address type: 0x06
          LE Public
          LE Random
@ MGMT Event: Discovering (0x0013) plen 2             {0x0003} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)
@ MGMT Event: Discovering (0x0013) plen 2             {0x0002} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)
@ MGMT Event: Discovering (0x0013) plen 2             {0x0001} [hci0] 27.422067
        Address type: 0x06
          LE Public
          LE Random
        Discovery: Enabled (0x01)

Signed-off-by: João Paulo Rechi Vita <jprvita@endlessm.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
awcurless pushed a commit to awcurless/linux-hardened that referenced this issue Jun 4, 2019
[ Upstream commit ff612ba ]

We've been seeing the following sporadically throughout our fleet

panic: kernel BUG at fs/btrfs/relocation.c:4584!
netversion: 5.0-0
Backtrace:
 #0 [ffffc90003adb880] machine_kexec at ffffffff81041da8
 anthraxx#1 [ffffc90003adb8c8] __crash_kexec at ffffffff8110396c
 anthraxx#2 [ffffc90003adb988] crash_kexec at ffffffff811048ad
 anthraxx#3 [ffffc90003adb9a0] oops_end at ffffffff8101c19a
 anthraxx#4 [ffffc90003adb9c0] do_trap at ffffffff81019114
 anthraxx#5 [ffffc90003adba00] do_error_trap at ffffffff810195d0
 anthraxx#6 [ffffc90003adbab0] invalid_op at ffffffff81a00a9b
    [exception RIP: btrfs_reloc_cow_block+692]
    RIP: ffffffff8143b614  RSP: ffffc90003adbb68  RFLAGS: 00010246
    RAX: fffffffffffffff7  RBX: ffff8806b9c32000  RCX: ffff8806aad00690
    RDX: ffff880850b295e0  RSI: ffff8806b9c32000  RDI: ffff88084f205bd0
    RBP: ffff880849415000   R8: ffffc90003adbbe0   R9: ffff88085ac90000
    R10: ffff8805f7369140  R11: 0000000000000000  R12: ffff880850b295e0
    R13: ffff88084f205bd0  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 anthraxx#7 [ffffc90003adbbb0] __btrfs_cow_block at ffffffff813bf1cd
 anthraxx#8 [ffffc90003adbc28] btrfs_cow_block at ffffffff813bf4b3
 anthraxx#9 [ffffc90003adbc78] btrfs_search_slot at ffffffff813c2e6c

The way relocation moves data extents is by creating a reloc inode and
preallocating extents in this inode and then copying the data into these
preallocated extents.  Once we've done this for all of our extents,
we'll write out these dirty pages, which marks the extent written, and
goes into btrfs_reloc_cow_block().  From here we get our current
reloc_control, which _should_ match the reloc_control for the current
block group we're relocating.

However if we get an ENOSPC in this path at some point we'll bail out,
never initiating writeback on this inode.  Not a huge deal, unless we
happen to be doing relocation on a different block group, and this block
group is now rc->stage == UPDATE_DATA_PTRS.  This trips the BUG_ON() in
btrfs_reloc_cow_block(), because we expect to be done modifying the data
inode.  We are in fact done modifying the metadata for the data inode
we're currently using, but not the one from the failed block group, and
thus we BUG_ON().

(This happens when writeback finishes for extents from the previous
group, when we are at btrfs_finish_ordered_io() which updates the data
reloc tree (inode item, drops/adds extent items, etc).)

Fix this by writing out the reloc data inode always, and then breaking
out of the loop after that point to keep from tripping this BUG_ON()
later.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ add note from Filipe ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jun 9, 2019
… allocation

commit a1ad1cc upstream.

After memory allocation failure vc_allocate() doesn't clean up data
which has been initialized in visual_init(). In case of fbcon this
leads to divide-by-0 in fbcon_init() on next open of the same tty.

memory allocation in vc_allocate() may fail here:
1097:     vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);

on next open() fbcon_init() skips vc_font.data initialization:
1088:     if (!p->fontdata) {

division by zero in fbcon_init() happens here:
1149:     new_cols /= vc->vc_font.width;

Additional check is needed in fbcon_deinit() to prevent
usage of uninitialized vc_screenbuf:

1251:        if (vc->vc_hi_font_mask && vc->vc_screenbuf)
1252:                set_vc_hi_font(vc, false);

Crash:

 #6 [ffffc90001eafa60] divide_error at ffffffff81a00be4
    [exception RIP: fbcon_init+463]
    RIP: ffffffff814b860f  RSP: ffffc90001eafb18  RFLAGS: 00010246
...
 #7 [ffffc90001eafb60] visual_init at ffffffff8154c36e
 #8 [ffffc90001eafb80] vc_allocate at ffffffff8154f53c
 #9 [ffffc90001eafbc8] con_install at ffffffff8154f624
...

Signed-off-by: Grzegorz Halat <ghalat@redhat.com>
Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Jun 9, 2019
… allocation

commit a1ad1cc upstream.

After memory allocation failure vc_allocate() doesn't clean up data
which has been initialized in visual_init(). In case of fbcon this
leads to divide-by-0 in fbcon_init() on next open of the same tty.

memory allocation in vc_allocate() may fail here:
1097:     vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);

on next open() fbcon_init() skips vc_font.data initialization:
1088:     if (!p->fontdata) {

division by zero in fbcon_init() happens here:
1149:     new_cols /= vc->vc_font.width;

Additional check is needed in fbcon_deinit() to prevent
usage of uninitialized vc_screenbuf:

1251:        if (vc->vc_hi_font_mask && vc->vc_screenbuf)
1252:                set_vc_hi_font(vc, false);

Crash:

 #6 [ffffc90001eafa60] divide_error at ffffffff81a00be4
    [exception RIP: fbcon_init+463]
    RIP: ffffffff814b860f  RSP: ffffc90001eafb18  RFLAGS: 00010246
...
 #7 [ffffc90001eafb60] visual_init at ffffffff8154c36e
 #8 [ffffc90001eafb80] vc_allocate at ffffffff8154f53c
 #9 [ffffc90001eafbc8] con_install at ffffffff8154f624
...

Signed-off-by: Grzegorz Halat <ghalat@redhat.com>
Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
@anthraxx
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anthraxx commented Jun 9, 2019

Fixed by bcea61f

@anthraxx anthraxx closed this as completed Jun 9, 2019
anthraxx pushed a commit that referenced this issue Jun 16, 2019
[ Upstream commit 347ab94 ]

This patch fixes deadlock warning if removing PWM device
when CONFIG_PROVE_LOCKING is enabled.

This issue can be reproceduced by the following steps on
the R-Car H3 Salvator-X board if the backlight is disabled:

 # cd /sys/class/pwm/pwmchip0
 # echo 0 > export
 # ls
 device  export  npwm  power  pwm0  subsystem  uevent  unexport
 # cd device/driver
 # ls
 bind  e6e31000.pwm  uevent  unbind
 # echo e6e31000.pwm > unbind

[   87.659974] ======================================================
[   87.666149] WARNING: possible circular locking dependency detected
[   87.672327] 5.0.0 #7 Not tainted
[   87.675549] ------------------------------------------------------
[   87.681723] bash/2986 is trying to acquire lock:
[   87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0
[   87.694528]
[   87.694528] but task is already holding lock:
[   87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.707405]
[   87.707405] which lock already depends on the new lock.
[   87.707405]
[   87.715574]
[   87.715574] the existing dependency chain (in reverse order) is:
[   87.723048]
[   87.723048] -> #1 (pwm_lock){+.+.}:
[   87.728017]        __mutex_lock+0x70/0x7e4
[   87.732108]        mutex_lock_nested+0x1c/0x24
[   87.736547]        pwm_request_from_chip.part.6+0x34/0x74
[   87.741940]        pwm_request_from_chip+0x20/0x40
[   87.746725]        export_store+0x6c/0x1f4
[   87.750820]        dev_attr_store+0x18/0x28
[   87.754998]        sysfs_kf_write+0x54/0x64
[   87.759175]        kernfs_fop_write+0xe4/0x1e8
[   87.763615]        __vfs_write+0x40/0x184
[   87.767619]        vfs_write+0xa8/0x19c
[   87.771448]        ksys_write+0x58/0xbc
[   87.775278]        __arm64_sys_write+0x18/0x20
[   87.779721]        el0_svc_common+0xd0/0x124
[   87.783986]        el0_svc_compat_handler+0x1c/0x24
[   87.788858]        el0_svc_compat+0x8/0x18
[   87.792947]
[   87.792947] -> #0 (kn->count#58){++++}:
[   87.798260]        lock_acquire+0xc4/0x22c
[   87.802353]        __kernfs_remove+0x258/0x2c4
[   87.806790]        kernfs_remove_by_name_ns+0x50/0xa0
[   87.811836]        remove_files.isra.1+0x38/0x78
[   87.816447]        sysfs_remove_group+0x48/0x98
[   87.820971]        sysfs_remove_groups+0x34/0x4c
[   87.825583]        device_remove_attrs+0x6c/0x7c
[   87.830197]        device_del+0x11c/0x33c
[   87.834201]        device_unregister+0x14/0x2c
[   87.838638]        pwmchip_sysfs_unexport+0x40/0x4c
[   87.843509]        pwmchip_remove+0xf4/0x13c
[   87.847773]        rcar_pwm_remove+0x28/0x34
[   87.852039]        platform_drv_remove+0x24/0x64
[   87.856651]        device_release_driver_internal+0x18c/0x21c
[   87.862391]        device_release_driver+0x14/0x1c
[   87.867175]        unbind_store+0xe0/0x124
[   87.871265]        drv_attr_store+0x20/0x30
[   87.875442]        sysfs_kf_write+0x54/0x64
[   87.879618]        kernfs_fop_write+0xe4/0x1e8
[   87.884055]        __vfs_write+0x40/0x184
[   87.888057]        vfs_write+0xa8/0x19c
[   87.891887]        ksys_write+0x58/0xbc
[   87.895716]        __arm64_sys_write+0x18/0x20
[   87.900154]        el0_svc_common+0xd0/0x124
[   87.904417]        el0_svc_compat_handler+0x1c/0x24
[   87.909289]        el0_svc_compat+0x8/0x18
[   87.913378]
[   87.913378] other info that might help us debug this:
[   87.913378]
[   87.921374]  Possible unsafe locking scenario:
[   87.921374]
[   87.927286]        CPU0                    CPU1
[   87.931808]        ----                    ----
[   87.936331]   lock(pwm_lock);
[   87.939293]                                lock(kn->count#58);
[   87.945120]                                lock(pwm_lock);
[   87.950599]   lock(kn->count#58);
[   87.953908]
[   87.953908]  *** DEADLOCK ***
[   87.953908]
[   87.959821] 4 locks held by bash/2986:
[   87.963563]  #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c
[   87.971044]  #1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8
[   87.978872]  #2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c
[   87.988001]  #3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.995481]
[   87.995481] stack backtrace:
[   87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 #7
[   88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT)
[   88.012791] Call trace:
[   88.015235]  dump_backtrace+0x0/0x190
[   88.018891]  show_stack+0x14/0x1c
[   88.022204]  dump_stack+0xb0/0xec
[   88.025514]  print_circular_bug.isra.32+0x1d0/0x2e0
[   88.030385]  __lock_acquire+0x1318/0x1864
[   88.034388]  lock_acquire+0xc4/0x22c
[   88.037958]  __kernfs_remove+0x258/0x2c4
[   88.041874]  kernfs_remove_by_name_ns+0x50/0xa0
[   88.046398]  remove_files.isra.1+0x38/0x78
[   88.050487]  sysfs_remove_group+0x48/0x98
[   88.054490]  sysfs_remove_groups+0x34/0x4c
[   88.058580]  device_remove_attrs+0x6c/0x7c
[   88.062671]  device_del+0x11c/0x33c
[   88.066154]  device_unregister+0x14/0x2c
[   88.070070]  pwmchip_sysfs_unexport+0x40/0x4c
[   88.074421]  pwmchip_remove+0xf4/0x13c
[   88.078163]  rcar_pwm_remove+0x28/0x34
[   88.081906]  platform_drv_remove+0x24/0x64
[   88.085996]  device_release_driver_internal+0x18c/0x21c
[   88.091215]  device_release_driver+0x14/0x1c
[   88.095478]  unbind_store+0xe0/0x124
[   88.099048]  drv_attr_store+0x20/0x30
[   88.102704]  sysfs_kf_write+0x54/0x64
[   88.106359]  kernfs_fop_write+0xe4/0x1e8
[   88.110275]  __vfs_write+0x40/0x184
[   88.113757]  vfs_write+0xa8/0x19c
[   88.117065]  ksys_write+0x58/0xbc
[   88.120374]  __arm64_sys_write+0x18/0x20
[   88.124291]  el0_svc_common+0xd0/0x124
[   88.128034]  el0_svc_compat_handler+0x1c/0x24
[   88.132384]  el0_svc_compat+0x8/0x18

The sysfs unexport in pwmchip_remove() is completely asymmetric
to what we do in pwmchip_add_with_polarity() and commit 0733424
("pwm: Unexport children before chip removal") is a strong indication
that this was wrong to begin with. We should just move
pwmchip_sysfs_unexport() where it belongs, which is right after
pwmchip_sysfs_unexport_children(). In that case, we do not need
separate functions anymore either.

We also really want to remove sysfs irrespective of whether or not
the chip will be removed as a result of pwmchip_remove(). We can only
assume that the driver will be gone after that, so we shouldn't leave
any dangling sysfs files around.

This warning disappears if we move pwmchip_sysfs_unexport() to
the top of pwmchip_remove(), pwmchip_sysfs_unexport_children().
That way it is also outside of the pwm_lock section, which indeed
doesn't seem to be needed.

Moving the pwmchip_sysfs_export() call outside of that section also
seems fine and it'd be perfectly symmetric with pwmchip_remove() again.

So, this patch fixes them.

Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com>
[shimoda: revise the commit log and code]
Fixes: 76abbdd ("pwm: Add sysfs interface")
Fixes: 0733424 ("pwm: Unexport children before chip removal")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jun 16, 2019
[ Upstream commit 347ab94 ]

This patch fixes deadlock warning if removing PWM device
when CONFIG_PROVE_LOCKING is enabled.

This issue can be reproceduced by the following steps on
the R-Car H3 Salvator-X board if the backlight is disabled:

 # cd /sys/class/pwm/pwmchip0
 # echo 0 > export
 # ls
 device  export  npwm  power  pwm0  subsystem  uevent  unexport
 # cd device/driver
 # ls
 bind  e6e31000.pwm  uevent  unbind
 # echo e6e31000.pwm > unbind

[   87.659974] ======================================================
[   87.666149] WARNING: possible circular locking dependency detected
[   87.672327] 5.0.0 #7 Not tainted
[   87.675549] ------------------------------------------------------
[   87.681723] bash/2986 is trying to acquire lock:
[   87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0
[   87.694528]
[   87.694528] but task is already holding lock:
[   87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.707405]
[   87.707405] which lock already depends on the new lock.
[   87.707405]
[   87.715574]
[   87.715574] the existing dependency chain (in reverse order) is:
[   87.723048]
[   87.723048] -> #1 (pwm_lock){+.+.}:
[   87.728017]        __mutex_lock+0x70/0x7e4
[   87.732108]        mutex_lock_nested+0x1c/0x24
[   87.736547]        pwm_request_from_chip.part.6+0x34/0x74
[   87.741940]        pwm_request_from_chip+0x20/0x40
[   87.746725]        export_store+0x6c/0x1f4
[   87.750820]        dev_attr_store+0x18/0x28
[   87.754998]        sysfs_kf_write+0x54/0x64
[   87.759175]        kernfs_fop_write+0xe4/0x1e8
[   87.763615]        __vfs_write+0x40/0x184
[   87.767619]        vfs_write+0xa8/0x19c
[   87.771448]        ksys_write+0x58/0xbc
[   87.775278]        __arm64_sys_write+0x18/0x20
[   87.779721]        el0_svc_common+0xd0/0x124
[   87.783986]        el0_svc_compat_handler+0x1c/0x24
[   87.788858]        el0_svc_compat+0x8/0x18
[   87.792947]
[   87.792947] -> #0 (kn->count#58){++++}:
[   87.798260]        lock_acquire+0xc4/0x22c
[   87.802353]        __kernfs_remove+0x258/0x2c4
[   87.806790]        kernfs_remove_by_name_ns+0x50/0xa0
[   87.811836]        remove_files.isra.1+0x38/0x78
[   87.816447]        sysfs_remove_group+0x48/0x98
[   87.820971]        sysfs_remove_groups+0x34/0x4c
[   87.825583]        device_remove_attrs+0x6c/0x7c
[   87.830197]        device_del+0x11c/0x33c
[   87.834201]        device_unregister+0x14/0x2c
[   87.838638]        pwmchip_sysfs_unexport+0x40/0x4c
[   87.843509]        pwmchip_remove+0xf4/0x13c
[   87.847773]        rcar_pwm_remove+0x28/0x34
[   87.852039]        platform_drv_remove+0x24/0x64
[   87.856651]        device_release_driver_internal+0x18c/0x21c
[   87.862391]        device_release_driver+0x14/0x1c
[   87.867175]        unbind_store+0xe0/0x124
[   87.871265]        drv_attr_store+0x20/0x30
[   87.875442]        sysfs_kf_write+0x54/0x64
[   87.879618]        kernfs_fop_write+0xe4/0x1e8
[   87.884055]        __vfs_write+0x40/0x184
[   87.888057]        vfs_write+0xa8/0x19c
[   87.891887]        ksys_write+0x58/0xbc
[   87.895716]        __arm64_sys_write+0x18/0x20
[   87.900154]        el0_svc_common+0xd0/0x124
[   87.904417]        el0_svc_compat_handler+0x1c/0x24
[   87.909289]        el0_svc_compat+0x8/0x18
[   87.913378]
[   87.913378] other info that might help us debug this:
[   87.913378]
[   87.921374]  Possible unsafe locking scenario:
[   87.921374]
[   87.927286]        CPU0                    CPU1
[   87.931808]        ----                    ----
[   87.936331]   lock(pwm_lock);
[   87.939293]                                lock(kn->count#58);
[   87.945120]                                lock(pwm_lock);
[   87.950599]   lock(kn->count#58);
[   87.953908]
[   87.953908]  *** DEADLOCK ***
[   87.953908]
[   87.959821] 4 locks held by bash/2986:
[   87.963563]  #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c
[   87.971044]  #1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8
[   87.978872]  #2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c
[   87.988001]  #3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.995481]
[   87.995481] stack backtrace:
[   87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 #7
[   88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT)
[   88.012791] Call trace:
[   88.015235]  dump_backtrace+0x0/0x190
[   88.018891]  show_stack+0x14/0x1c
[   88.022204]  dump_stack+0xb0/0xec
[   88.025514]  print_circular_bug.isra.32+0x1d0/0x2e0
[   88.030385]  __lock_acquire+0x1318/0x1864
[   88.034388]  lock_acquire+0xc4/0x22c
[   88.037958]  __kernfs_remove+0x258/0x2c4
[   88.041874]  kernfs_remove_by_name_ns+0x50/0xa0
[   88.046398]  remove_files.isra.1+0x38/0x78
[   88.050487]  sysfs_remove_group+0x48/0x98
[   88.054490]  sysfs_remove_groups+0x34/0x4c
[   88.058580]  device_remove_attrs+0x6c/0x7c
[   88.062671]  device_del+0x11c/0x33c
[   88.066154]  device_unregister+0x14/0x2c
[   88.070070]  pwmchip_sysfs_unexport+0x40/0x4c
[   88.074421]  pwmchip_remove+0xf4/0x13c
[   88.078163]  rcar_pwm_remove+0x28/0x34
[   88.081906]  platform_drv_remove+0x24/0x64
[   88.085996]  device_release_driver_internal+0x18c/0x21c
[   88.091215]  device_release_driver+0x14/0x1c
[   88.095478]  unbind_store+0xe0/0x124
[   88.099048]  drv_attr_store+0x20/0x30
[   88.102704]  sysfs_kf_write+0x54/0x64
[   88.106359]  kernfs_fop_write+0xe4/0x1e8
[   88.110275]  __vfs_write+0x40/0x184
[   88.113757]  vfs_write+0xa8/0x19c
[   88.117065]  ksys_write+0x58/0xbc
[   88.120374]  __arm64_sys_write+0x18/0x20
[   88.124291]  el0_svc_common+0xd0/0x124
[   88.128034]  el0_svc_compat_handler+0x1c/0x24
[   88.132384]  el0_svc_compat+0x8/0x18

The sysfs unexport in pwmchip_remove() is completely asymmetric
to what we do in pwmchip_add_with_polarity() and commit 0733424
("pwm: Unexport children before chip removal") is a strong indication
that this was wrong to begin with. We should just move
pwmchip_sysfs_unexport() where it belongs, which is right after
pwmchip_sysfs_unexport_children(). In that case, we do not need
separate functions anymore either.

We also really want to remove sysfs irrespective of whether or not
the chip will be removed as a result of pwmchip_remove(). We can only
assume that the driver will be gone after that, so we shouldn't leave
any dangling sysfs files around.

This warning disappears if we move pwmchip_sysfs_unexport() to
the top of pwmchip_remove(), pwmchip_sysfs_unexport_children().
That way it is also outside of the pwm_lock section, which indeed
doesn't seem to be needed.

Moving the pwmchip_sysfs_export() call outside of that section also
seems fine and it'd be perfectly symmetric with pwmchip_remove() again.

So, this patch fixes them.

Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com>
[shimoda: revise the commit log and code]
Fixes: 76abbdd ("pwm: Add sysfs interface")
Fixes: 0733424 ("pwm: Unexport children before chip removal")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jun 16, 2019
[ Upstream commit 347ab94 ]

This patch fixes deadlock warning if removing PWM device
when CONFIG_PROVE_LOCKING is enabled.

This issue can be reproceduced by the following steps on
the R-Car H3 Salvator-X board if the backlight is disabled:

 # cd /sys/class/pwm/pwmchip0
 # echo 0 > export
 # ls
 device  export  npwm  power  pwm0  subsystem  uevent  unexport
 # cd device/driver
 # ls
 bind  e6e31000.pwm  uevent  unbind
 # echo e6e31000.pwm > unbind

[   87.659974] ======================================================
[   87.666149] WARNING: possible circular locking dependency detected
[   87.672327] 5.0.0 #7 Not tainted
[   87.675549] ------------------------------------------------------
[   87.681723] bash/2986 is trying to acquire lock:
[   87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0
[   87.694528]
[   87.694528] but task is already holding lock:
[   87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.707405]
[   87.707405] which lock already depends on the new lock.
[   87.707405]
[   87.715574]
[   87.715574] the existing dependency chain (in reverse order) is:
[   87.723048]
[   87.723048] -> #1 (pwm_lock){+.+.}:
[   87.728017]        __mutex_lock+0x70/0x7e4
[   87.732108]        mutex_lock_nested+0x1c/0x24
[   87.736547]        pwm_request_from_chip.part.6+0x34/0x74
[   87.741940]        pwm_request_from_chip+0x20/0x40
[   87.746725]        export_store+0x6c/0x1f4
[   87.750820]        dev_attr_store+0x18/0x28
[   87.754998]        sysfs_kf_write+0x54/0x64
[   87.759175]        kernfs_fop_write+0xe4/0x1e8
[   87.763615]        __vfs_write+0x40/0x184
[   87.767619]        vfs_write+0xa8/0x19c
[   87.771448]        ksys_write+0x58/0xbc
[   87.775278]        __arm64_sys_write+0x18/0x20
[   87.779721]        el0_svc_common+0xd0/0x124
[   87.783986]        el0_svc_compat_handler+0x1c/0x24
[   87.788858]        el0_svc_compat+0x8/0x18
[   87.792947]
[   87.792947] -> #0 (kn->count#58){++++}:
[   87.798260]        lock_acquire+0xc4/0x22c
[   87.802353]        __kernfs_remove+0x258/0x2c4
[   87.806790]        kernfs_remove_by_name_ns+0x50/0xa0
[   87.811836]        remove_files.isra.1+0x38/0x78
[   87.816447]        sysfs_remove_group+0x48/0x98
[   87.820971]        sysfs_remove_groups+0x34/0x4c
[   87.825583]        device_remove_attrs+0x6c/0x7c
[   87.830197]        device_del+0x11c/0x33c
[   87.834201]        device_unregister+0x14/0x2c
[   87.838638]        pwmchip_sysfs_unexport+0x40/0x4c
[   87.843509]        pwmchip_remove+0xf4/0x13c
[   87.847773]        rcar_pwm_remove+0x28/0x34
[   87.852039]        platform_drv_remove+0x24/0x64
[   87.856651]        device_release_driver_internal+0x18c/0x21c
[   87.862391]        device_release_driver+0x14/0x1c
[   87.867175]        unbind_store+0xe0/0x124
[   87.871265]        drv_attr_store+0x20/0x30
[   87.875442]        sysfs_kf_write+0x54/0x64
[   87.879618]        kernfs_fop_write+0xe4/0x1e8
[   87.884055]        __vfs_write+0x40/0x184
[   87.888057]        vfs_write+0xa8/0x19c
[   87.891887]        ksys_write+0x58/0xbc
[   87.895716]        __arm64_sys_write+0x18/0x20
[   87.900154]        el0_svc_common+0xd0/0x124
[   87.904417]        el0_svc_compat_handler+0x1c/0x24
[   87.909289]        el0_svc_compat+0x8/0x18
[   87.913378]
[   87.913378] other info that might help us debug this:
[   87.913378]
[   87.921374]  Possible unsafe locking scenario:
[   87.921374]
[   87.927286]        CPU0                    CPU1
[   87.931808]        ----                    ----
[   87.936331]   lock(pwm_lock);
[   87.939293]                                lock(kn->count#58);
[   87.945120]                                lock(pwm_lock);
[   87.950599]   lock(kn->count#58);
[   87.953908]
[   87.953908]  *** DEADLOCK ***
[   87.953908]
[   87.959821] 4 locks held by bash/2986:
[   87.963563]  #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c
[   87.971044]  #1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8
[   87.978872]  #2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c
[   87.988001]  #3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.995481]
[   87.995481] stack backtrace:
[   87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 #7
[   88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT)
[   88.012791] Call trace:
[   88.015235]  dump_backtrace+0x0/0x190
[   88.018891]  show_stack+0x14/0x1c
[   88.022204]  dump_stack+0xb0/0xec
[   88.025514]  print_circular_bug.isra.32+0x1d0/0x2e0
[   88.030385]  __lock_acquire+0x1318/0x1864
[   88.034388]  lock_acquire+0xc4/0x22c
[   88.037958]  __kernfs_remove+0x258/0x2c4
[   88.041874]  kernfs_remove_by_name_ns+0x50/0xa0
[   88.046398]  remove_files.isra.1+0x38/0x78
[   88.050487]  sysfs_remove_group+0x48/0x98
[   88.054490]  sysfs_remove_groups+0x34/0x4c
[   88.058580]  device_remove_attrs+0x6c/0x7c
[   88.062671]  device_del+0x11c/0x33c
[   88.066154]  device_unregister+0x14/0x2c
[   88.070070]  pwmchip_sysfs_unexport+0x40/0x4c
[   88.074421]  pwmchip_remove+0xf4/0x13c
[   88.078163]  rcar_pwm_remove+0x28/0x34
[   88.081906]  platform_drv_remove+0x24/0x64
[   88.085996]  device_release_driver_internal+0x18c/0x21c
[   88.091215]  device_release_driver+0x14/0x1c
[   88.095478]  unbind_store+0xe0/0x124
[   88.099048]  drv_attr_store+0x20/0x30
[   88.102704]  sysfs_kf_write+0x54/0x64
[   88.106359]  kernfs_fop_write+0xe4/0x1e8
[   88.110275]  __vfs_write+0x40/0x184
[   88.113757]  vfs_write+0xa8/0x19c
[   88.117065]  ksys_write+0x58/0xbc
[   88.120374]  __arm64_sys_write+0x18/0x20
[   88.124291]  el0_svc_common+0xd0/0x124
[   88.128034]  el0_svc_compat_handler+0x1c/0x24
[   88.132384]  el0_svc_compat+0x8/0x18

The sysfs unexport in pwmchip_remove() is completely asymmetric
to what we do in pwmchip_add_with_polarity() and commit 0733424
("pwm: Unexport children before chip removal") is a strong indication
that this was wrong to begin with. We should just move
pwmchip_sysfs_unexport() where it belongs, which is right after
pwmchip_sysfs_unexport_children(). In that case, we do not need
separate functions anymore either.

We also really want to remove sysfs irrespective of whether or not
the chip will be removed as a result of pwmchip_remove(). We can only
assume that the driver will be gone after that, so we shouldn't leave
any dangling sysfs files around.

This warning disappears if we move pwmchip_sysfs_unexport() to
the top of pwmchip_remove(), pwmchip_sysfs_unexport_children().
That way it is also outside of the pwm_lock section, which indeed
doesn't seem to be needed.

Moving the pwmchip_sysfs_export() call outside of that section also
seems fine and it'd be perfectly symmetric with pwmchip_remove() again.

So, this patch fixes them.

Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com>
[shimoda: revise the commit log and code]
Fixes: 76abbdd ("pwm: Add sysfs interface")
Fixes: 0733424 ("pwm: Unexport children before chip removal")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jul 24, 2019
commit c952b35 upstream.

bpf/btf write_* functions need ff->ph->env.

With this missing, pipe-mode (perf record -o -)  would crash like:

Program terminated with signal SIGSEGV, Segmentation fault.

This patch assign proper ph value to ff.

Committer testing:

  (gdb) run record -o -
  Starting program: /root/bin/perf record -o -
  PERFILE2
  <SNIP start of perf.data headers>
  Thread 1 "perf" received signal SIGSEGV, Segmentation fault.
  __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126
  126		memcpy(ff->buf + ff->offset, buf, size);
  (gdb) bt
  #0  __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126
  #1  do_write (ff=ff@entry=0x7fffffff8f80, buf=buf@entry=0x160, size=4) at util/header.c:137
  #2  0x00000000004eddba in write_bpf_prog_info (ff=0x7fffffff8f80, evlist=<optimized out>) at util/header.c:912
  #3  0x00000000004f69d7 in perf_event__synthesize_features (tool=tool@entry=0x97cc00 <record>, session=session@entry=0x7fffe9c6d010,
      evlist=0x7fffe9cae010, process=process@entry=0x4435d0 <process_synthesized_event>) at util/header.c:3695
  #4  0x0000000000443c79 in record__synthesize (tail=tail@entry=false, rec=0x97cc00 <record>) at builtin-record.c:1214
  #5  0x0000000000444ec9 in __cmd_record (rec=0x97cc00 <record>, argv=<optimized out>, argc=0) at builtin-record.c:1435
  #6  cmd_record (argc=0, argv=<optimized out>) at builtin-record.c:2450
  #7  0x00000000004ae3e9 in run_builtin (p=p@entry=0x98e058 <commands+216>, argc=argc@entry=3, argv=0x7fffffffd670) at perf.c:304
  #8  0x000000000042eded in handle_internal_command (argv=<optimized out>, argc=<optimized out>) at perf.c:356
  #9  run_argv (argcp=<optimized out>, argv=<optimized out>) at perf.c:400
  #10 main (argc=3, argv=<optimized out>) at perf.c:522
  (gdb)

After the patch the SEGSEGV is gone.

Reported-by: David Carrillo Cisneros <davidca@fb.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kernel-team@fb.com
Cc: stable@vger.kernel.org # v5.1+
Fixes: 606f972 ("perf bpf: Save bpf_prog_info information as headers to perf.data")
Link: http://lkml.kernel.org/r/20190620010453.4118689-1-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Aug 17, 2019
commit d0a255e upstream.

A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Aug 17, 2019
commit d0a255e upstream.

A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Aug 17, 2019
commit d0a255e upstream.

A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Sep 2, 2019
commit cf3591e upstream.

Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Sep 2, 2019
[ Upstream commit df9576d ]

When running ltp's oom test with kmemleak enabled, the below warning was
triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is
passed in:

  WARNING: CPU: 105 PID: 2138 at mm/page_alloc.c:4608 __alloc_pages_nodemask+0x1c31/0x1d50
  Modules linked in: loop dax_pmem dax_pmem_core ip_tables x_tables xfs virtio_net net_failover virtio_blk failover ata_generic virtio_pci virtio_ring virtio libata
  CPU: 105 PID: 2138 Comm: oom01 Not tainted 5.2.0-next-20190710+ #7
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
  RIP: 0010:__alloc_pages_nodemask+0x1c31/0x1d50
  ...
   kmemleak_alloc+0x4e/0xb0
   kmem_cache_alloc+0x2a7/0x3e0
   mempool_alloc_slab+0x2d/0x40
   mempool_alloc+0x118/0x2b0
   bio_alloc_bioset+0x19d/0x350
   get_swap_bio+0x80/0x230
   __swap_writepage+0x5ff/0xb20

The mempool_alloc_slab() clears __GFP_DIRECT_RECLAIM, however kmemleak
has __GFP_NOFAIL set all the time due to d9570ee ("kmemleak:
allow to coexist with fault injection").  But, it doesn't make any sense
to have __GFP_NOFAIL and ~__GFP_DIRECT_RECLAIM specified at the same
time.

According to the discussion on the mailing list, the commit should be
reverted for short term solution.  Catalin Marinas would follow up with
a better solution for longer term.

The failure rate of kmemleak metadata allocation may increase in some
circumstances, but this should be expected side effect.

Link: http://lkml.kernel.org/r/1563299431-111710-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: d9570ee ("kmemleak: allow to coexist with fault injection")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Sep 2, 2019
commit cf3591e upstream.

Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Sep 2, 2019
[ Upstream commit df9576d ]

When running ltp's oom test with kmemleak enabled, the below warning was
triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is
passed in:

  WARNING: CPU: 105 PID: 2138 at mm/page_alloc.c:4608 __alloc_pages_nodemask+0x1c31/0x1d50
  Modules linked in: loop dax_pmem dax_pmem_core ip_tables x_tables xfs virtio_net net_failover virtio_blk failover ata_generic virtio_pci virtio_ring virtio libata
  CPU: 105 PID: 2138 Comm: oom01 Not tainted 5.2.0-next-20190710+ #7
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
  RIP: 0010:__alloc_pages_nodemask+0x1c31/0x1d50
  ...
   kmemleak_alloc+0x4e/0xb0
   kmem_cache_alloc+0x2a7/0x3e0
   mempool_alloc_slab+0x2d/0x40
   mempool_alloc+0x118/0x2b0
   bio_alloc_bioset+0x19d/0x350
   get_swap_bio+0x80/0x230
   __swap_writepage+0x5ff/0xb20

The mempool_alloc_slab() clears __GFP_DIRECT_RECLAIM, however kmemleak
has __GFP_NOFAIL set all the time due to d9570ee ("kmemleak:
allow to coexist with fault injection").  But, it doesn't make any sense
to have __GFP_NOFAIL and ~__GFP_DIRECT_RECLAIM specified at the same
time.

According to the discussion on the mailing list, the commit should be
reverted for short term solution.  Catalin Marinas would follow up with
a better solution for longer term.

The failure rate of kmemleak metadata allocation may increase in some
circumstances, but this should be expected side effect.

Link: http://lkml.kernel.org/r/1563299431-111710-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: d9570ee ("kmemleak: allow to coexist with fault injection")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Sep 2, 2019
commit cf3591e upstream.

Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Oct 12, 2019
[ Upstream commit 0216234 ]

We release wrong pointer on error path in cpu_cache_level__read
function, leading to segfault:

  (gdb) r record ls
  Starting program: /root/perf/tools/perf/perf record ls
  ...
  [ perf record: Woken up 1 times to write data ]
  double free or corruption (out)

  Thread 1 "perf" received signal SIGABRT, Aborted.
  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  (gdb) bt
  #0  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  #1  0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6
  #2  0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6
  #3  0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6
  #4  0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6
  #5  0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc..
  #6  0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac..
  #7  0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz..
  ...

Releasing the proper pointer.

Fixes: 720e98b ("perf tools: Add perf data cache feature")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org: # v4.6+
Link: http://lore.kernel.org/lkml/20190912105235.10689-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Oct 12, 2019
[ Upstream commit 443f2d5 ]

Observe a segmentation fault when 'perf stat' is asked to repeat forever
with the interval option.

Without fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
  #           time             counts unit events
       5.000211692  3,13,89,82,34,157      cycles
      10.000380119  1,53,98,52,22,294      cycles
      10.040467280       17,16,79,265      cycles
  Segmentation fault

This problem was only observed when we use forever option aka -r 0 and
works with limited repeats. Calling print_counter with ts being set to
NULL, is not a correct option when interval is set. Hence avoid
print_counter(NULL,..)  if interval is set.

With fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
   #           time             counts unit events
       5.019866622  3,15,14,43,08,697      cycles
      10.039865756  3,15,16,31,95,261      cycles
      10.059950628     1,26,05,47,158      cycles
       5.009902655  3,14,52,62,33,932      cycles
      10.019880228  3,14,52,22,89,154      cycles
      10.030543876       66,90,18,333      cycles
       5.009848281  3,14,51,98,25,437      cycles
      10.029854402  3,15,14,93,04,918      cycles
       5.009834177  3,14,51,95,92,316      cycles

Committer notes:

Did the 'git bisect' to find the cset introducing the problem to add the
Fixes tag below, and at that time the problem reproduced as:

  (gdb) run stat -r0 -I500 sleep 1
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  866		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep);
  (gdb) bt
  #0  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  #1  0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938
  #2  0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=<optimized out>) at builtin-stat.c:1411
  #3  0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 <commands+216>, argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370
  #4  0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429
  #5  0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473
  #6  0x000000000045cac9 in main (argc=<optimized out>, argv=<optimized out>) at perf.c:588
  (gdb)

Mostly the same as just before this patch:

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  964		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep);
  (gdb) bt
  #0  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  #1  0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 <stat_config>, _target=0xa1f0c0 <target>, ts=0x0, argc=2, argv=0x7fffffffd670)
      at util/stat-display.c:1172
  #2  0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656
  #3  0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960
  #4  0x00000000004dd2e0 in run_builtin (p=0xa30e00 <commands+288>, argc=5, argv=0x7fffffffd670) at perf.c:310
  #5  0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362
  #6  0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406
  #7  0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531
  (gdb)

Fixes: d4f63a4 ("perf stat: Introduce print_counters function")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.2+
Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Oct 12, 2019
commit 443f2d5 upstream.

Observe a segmentation fault when 'perf stat' is asked to repeat forever
with the interval option.

Without fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
  #           time             counts unit events
       5.000211692  3,13,89,82,34,157      cycles
      10.000380119  1,53,98,52,22,294      cycles
      10.040467280       17,16,79,265      cycles
  Segmentation fault

This problem was only observed when we use forever option aka -r 0 and
works with limited repeats. Calling print_counter with ts being set to
NULL, is not a correct option when interval is set. Hence avoid
print_counter(NULL,..)  if interval is set.

With fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
   #           time             counts unit events
       5.019866622  3,15,14,43,08,697      cycles
      10.039865756  3,15,16,31,95,261      cycles
      10.059950628     1,26,05,47,158      cycles
       5.009902655  3,14,52,62,33,932      cycles
      10.019880228  3,14,52,22,89,154      cycles
      10.030543876       66,90,18,333      cycles
       5.009848281  3,14,51,98,25,437      cycles
      10.029854402  3,15,14,93,04,918      cycles
       5.009834177  3,14,51,95,92,316      cycles

Committer notes:

Did the 'git bisect' to find the cset introducing the problem to add the
Fixes tag below, and at that time the problem reproduced as:

  (gdb) run stat -r0 -I500 sleep 1
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  866		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep);
  (gdb) bt
  #0  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  #1  0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938
  #2  0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=<optimized out>) at builtin-stat.c:1411
  #3  0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 <commands+216>, argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370
  #4  0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429
  #5  0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473
  #6  0x000000000045cac9 in main (argc=<optimized out>, argv=<optimized out>) at perf.c:588
  (gdb)

Mostly the same as just before this patch:

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  964		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep);
  (gdb) bt
  #0  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  #1  0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 <stat_config>, _target=0xa1f0c0 <target>, ts=0x0, argc=2, argv=0x7fffffffd670)
      at util/stat-display.c:1172
  #2  0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656
  #3  0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960
  #4  0x00000000004dd2e0 in run_builtin (p=0xa30e00 <commands+288>, argc=5, argv=0x7fffffffd670) at perf.c:310
  #5  0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362
  #6  0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406
  #7  0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531
  (gdb)

Fixes: d4f63a4 ("perf stat: Introduce print_counters function")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.2+
Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Oct 12, 2019
[ Upstream commit 0216234 ]

We release wrong pointer on error path in cpu_cache_level__read
function, leading to segfault:

  (gdb) r record ls
  Starting program: /root/perf/tools/perf/perf record ls
  ...
  [ perf record: Woken up 1 times to write data ]
  double free or corruption (out)

  Thread 1 "perf" received signal SIGABRT, Aborted.
  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  (gdb) bt
  #0  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  #1  0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6
  #2  0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6
  #3  0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6
  #4  0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6
  #5  0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc..
  #6  0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac..
  #7  0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz..
  ...

Releasing the proper pointer.

Fixes: 720e98b ("perf tools: Add perf data cache feature")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org: # v4.6+
Link: http://lore.kernel.org/lkml/20190912105235.10689-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Oct 17, 2019
commit 0216234 upstream.

We release wrong pointer on error path in cpu_cache_level__read
function, leading to segfault:

  (gdb) r record ls
  Starting program: /root/perf/tools/perf/perf record ls
  ...
  [ perf record: Woken up 1 times to write data ]
  double free or corruption (out)

  Thread 1 "perf" received signal SIGABRT, Aborted.
  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  (gdb) bt
  #0  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  #1  0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6
  #2  0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6
  #3  0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6
  #4  0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6
  #5  0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc..
  #6  0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac..
  #7  0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz..
  ...

Releasing the proper pointer.

Fixes: 720e98b ("perf tools: Add perf data cache feature")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org: # v4.6+
Link: http://lore.kernel.org/lkml/20190912105235.10689-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Oct 17, 2019
commit 443f2d5 upstream.

Observe a segmentation fault when 'perf stat' is asked to repeat forever
with the interval option.

Without fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
  #           time             counts unit events
       5.000211692  3,13,89,82,34,157      cycles
      10.000380119  1,53,98,52,22,294      cycles
      10.040467280       17,16,79,265      cycles
  Segmentation fault

This problem was only observed when we use forever option aka -r 0 and
works with limited repeats. Calling print_counter with ts being set to
NULL, is not a correct option when interval is set. Hence avoid
print_counter(NULL,..)  if interval is set.

With fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
   #           time             counts unit events
       5.019866622  3,15,14,43,08,697      cycles
      10.039865756  3,15,16,31,95,261      cycles
      10.059950628     1,26,05,47,158      cycles
       5.009902655  3,14,52,62,33,932      cycles
      10.019880228  3,14,52,22,89,154      cycles
      10.030543876       66,90,18,333      cycles
       5.009848281  3,14,51,98,25,437      cycles
      10.029854402  3,15,14,93,04,918      cycles
       5.009834177  3,14,51,95,92,316      cycles

Committer notes:

Did the 'git bisect' to find the cset introducing the problem to add the
Fixes tag below, and at that time the problem reproduced as:

  (gdb) run stat -r0 -I500 sleep 1
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  866		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep);
  (gdb) bt
  #0  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  #1  0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938
  #2  0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=<optimized out>) at builtin-stat.c:1411
  #3  0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 <commands+216>, argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370
  #4  0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429
  #5  0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473
  #6  0x000000000045cac9 in main (argc=<optimized out>, argv=<optimized out>) at perf.c:588
  (gdb)

Mostly the same as just before this patch:

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  964		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep);
  (gdb) bt
  #0  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  #1  0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 <stat_config>, _target=0xa1f0c0 <target>, ts=0x0, argc=2, argv=0x7fffffffd670)
      at util/stat-display.c:1172
  #2  0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656
  #3  0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960
  #4  0x00000000004dd2e0 in run_builtin (p=0xa30e00 <commands+288>, argc=5, argv=0x7fffffffd670) at perf.c:310
  #5  0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362
  #6  0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406
  #7  0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531
  (gdb)

Fixes: d4f63a4 ("perf stat: Introduce print_counters function")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.2+
Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Nov 6, 2024
commit 0a93f2c upstream.

The Tx BD rings are disabled first in enetc_stop() and the driver
waits for them to become empty. This operation is not safe while
the ring is actively transmitting frames, and will cause the ring
to not be empty and hardware exception. As described in the NETC
block guide, software should only disable an active Tx ring after
all pending ring entries have been consumed (i.e. when PI = CI).
Disabling a transmit ring that is actively processing BDs risks
a HW-SW race hazard whereby a hardware resource becomes assigned
to work on one or more ring entries only to have those entries be
removed due to the ring becoming disabled.

When testing XDP_REDIRECT feautre, although all frames were blocked
from being put into Tx rings during ring reconfiguration, the similar
warning log was still encountered:

fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #6 clear
fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #7 clear

The reason is that when there are still unsent frames in the Tx ring,
disabling the Tx ring causes the remaining frames to be unable to be
sent out. And the Tx ring cannot be restored, which means that even
if the xdp program is uninstalled, the Tx frames cannot be sent out
anymore. Therefore, correct the operation order in enect_start() and
enect_stop().

Fixes: ff58fda ("net: enetc: prioritize ability to go down over packet processing")
Cc: stable@vger.kernel.org
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20241010092056.298128-4-wei.fang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Nov 7, 2024
commit ac01c8c upstream.

AddressSanitizer found a use-after-free bug in the symbol code which
manifested as 'perf top' segfaulting.

  ==1238389==ERROR: AddressSanitizer: heap-use-after-free on address 0x60b00c48844b at pc 0x5650d8035961 bp 0x7f751aaecc90 sp 0x7f751aaecc80
  READ of size 1 at 0x60b00c48844b thread T193
      #0 0x5650d8035960 in _sort__sym_cmp util/sort.c:310
      #1 0x5650d8043744 in hist_entry__cmp util/hist.c:1286
      #2 0x5650d8043951 in hists__findnew_entry util/hist.c:614
      #3 0x5650d804568f in __hists__add_entry util/hist.c:754
      #4 0x5650d8045bf9 in hists__add_entry util/hist.c:772
      #5 0x5650d8045df1 in iter_add_single_normal_entry util/hist.c:997
      #6 0x5650d8043326 in hist_entry_iter__add util/hist.c:1242
      #7 0x5650d7ceeefe in perf_event__process_sample /home/matt/src/linux/tools/perf/builtin-top.c:845
      #8 0x5650d7ceeefe in deliver_event /home/matt/src/linux/tools/perf/builtin-top.c:1208
      #9 0x5650d7fdb51b in do_flush util/ordered-events.c:245
      #10 0x5650d7fdb51b in __ordered_events__flush util/ordered-events.c:324
      #11 0x5650d7ced743 in process_thread /home/matt/src/linux/tools/perf/builtin-top.c:1120
      #12 0x7f757ef1f133 in start_thread nptl/pthread_create.c:442
      #13 0x7f757ef9f7db in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

When updating hist maps it's also necessary to update the hist symbol
reference because the old one gets freed in map__put().

While this bug was probably introduced with 5c24b67 ("perf
tools: Replace map->referenced & maps->removed_maps with map->refcnt"),
the symbol objects were leaked until c087e94 ("perf machine:
Fix refcount usage when processing PERF_RECORD_KSYMBOL") was merged so
the bug was masked.

Fixes: c087e94 ("perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL")
Reported-by: Yunzhao Li <yunzhao@cloudflare.com>
Signed-off-by: Matt Fleming (Cloudflare) <matt@readmodwrite.com>
Cc: Ian Rogers <irogers@google.com>
Cc: kernel-team@cloudflare.com
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: stable@vger.kernel.org # v5.13+
Link: https://lore.kernel.org/r/20240815142212.3834625-1-matt@readmodwrite.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Nov 7, 2024
commit 9af2efe upstream.

The fields in the hist_entry are filled on-demand which means they only
have meaningful values when relevant sort keys are used.

So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in
the hist entry can be garbage.  So it shouldn't access it
unconditionally.

I got a segfault, when I wanted to see cgroup profiles.

  $ sudo perf record -a --all-cgroups --synth=cgroup true

  $ sudo perf report -s cgroup

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  48		return RC_CHK_ACCESS(map)->dso;
  (gdb) bt
  #0  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  #1  0x00005555557aa39b in map__load (map=0x0) at util/map.c:344
  #2  0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385
  #3  0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true)
      at util/hist.c:644
  #4  0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761
  #5  0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779
  #6  0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015
  #7  0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0)
      at util/hist.c:1260
  #8  0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0,
      machine=0x5555560388e8) at builtin-report.c:334
  #9  0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232
  #10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271
  #11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0,
      file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354
  #12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132
  #13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245
  #14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324
  #15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342
  #16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60)
      at util/session.c:780
  #17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688,
      file_path=0x555556038ff0 "perf.data") at util/session.c:1406

As you can see the entry->ms.map was NULL even if he->ms.map has a
value.  This is because 'sym' sort key is not given, so it cannot assume
whether he->ms.sym and entry->ms.sym is the same.  I only checked the
'sym' sort key here as it implies 'dso' behavior (so maps are the same).

Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Matt Fleming <matt@readmodwrite.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240826221045.1202305-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Nov 17, 2024
commit cf96b8e upstream.

ASan reports a memory leak caused by evlist not being deleted on exit in
perf-report, perf-script and perf-data.
The problem is caused by evlist->session not being deleted, which is
allocated in perf_session__read_header, called in perf_session__new if
perf_data is in read mode.
In case of write mode, the session->evlist is filled by the caller.
This patch solves the problem by calling evlist__delete in
perf_session__delete if perf_data is in read mode.

Changes in v2:
 - call evlist__delete from within perf_session__delete

v1: https://lore.kernel.org/lkml/20210621234317.235545-1-rickyman7@gmail.com/

ASan report follows:

$ ./perf script report flamegraph
=================================================================
==227640==ERROR: LeakSanitizer: detected memory leaks

<SNIP unrelated>

Indirect leak of 2704 byte(s) in 1 object(s) allocated from:
    #0 0x4f4137 in calloc (/home/user/linux/tools/perf/perf+0x4f4137)
    #1 0xbe3d56 in zalloc /home/user/linux/tools/lib/perf/../../lib/zalloc.c:8:9
    #2 0x7f999e in evlist__new /home/user/linux/tools/perf/util/evlist.c:77:26
    #3 0x8ad938 in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3797:20
    #4 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6
    #5 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10
    #6 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12
    #7 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
    #8 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
    #9 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2
    #10 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3
    #11 0x7f5260654b74  (/lib64/libc.so.6+0x27b74)

Indirect leak of 568 byte(s) in 1 object(s) allocated from:
    #0 0x4f4137 in calloc (/home/user/linux/tools/perf/perf+0x4f4137)
    #1 0xbe3d56 in zalloc /home/user/linux/tools/lib/perf/../../lib/zalloc.c:8:9
    #2 0x80ce88 in evsel__new_idx /home/user/linux/tools/perf/util/evsel.c:268:24
    #3 0x8aed93 in evsel__new /home/user/linux/tools/perf/util/evsel.h:210:9
    #4 0x8ae07e in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3853:11
    #5 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6
    #6 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10
    #7 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12
    #8 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
    #9 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
    #10 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2
    #11 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3
    #12 0x7f5260654b74  (/lib64/libc.so.6+0x27b74)

Indirect leak of 264 byte(s) in 1 object(s) allocated from:
    #0 0x4f4137 in calloc (/home/user/linux/tools/perf/perf+0x4f4137)
    #1 0xbe3d56 in zalloc /home/user/linux/tools/lib/perf/../../lib/zalloc.c:8:9
    #2 0xbe3e70 in xyarray__new /home/user/linux/tools/lib/perf/xyarray.c:10:23
    #3 0xbd7754 in perf_evsel__alloc_id /home/user/linux/tools/lib/perf/evsel.c:361:21
    #4 0x8ae201 in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3871:7
    #5 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6
    #6 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10
    #7 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12
    #8 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
    #9 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
    #10 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2
    #11 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3
    #12 0x7f5260654b74  (/lib64/libc.so.6+0x27b74)

Indirect leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x4f4137 in calloc (/home/user/linux/tools/perf/perf+0x4f4137)
    #1 0xbe3d56 in zalloc /home/user/linux/tools/lib/perf/../../lib/zalloc.c:8:9
    #2 0xbd77e0 in perf_evsel__alloc_id /home/user/linux/tools/lib/perf/evsel.c:365:14
    #3 0x8ae201 in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3871:7
    #4 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6
    #5 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10
    #6 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12
    #7 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
    #8 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
    #9 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2
    #10 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3
    #11 0x7f5260654b74  (/lib64/libc.so.6+0x27b74)

Indirect leak of 7 byte(s) in 1 object(s) allocated from:
    #0 0x4b8207 in strdup (/home/user/linux/tools/perf/perf+0x4b8207)
    #1 0x8b4459 in evlist__set_event_name /home/user/linux/tools/perf/util/header.c:2292:16
    #2 0x89d862 in process_event_desc /home/user/linux/tools/perf/util/header.c:2313:3
    #3 0x8af319 in perf_file_section__process /home/user/linux/tools/perf/util/header.c:3651:9
    #4 0x8aa6e9 in perf_header__process_sections /home/user/linux/tools/perf/util/header.c:3427:9
    #5 0x8ae3e7 in perf_session__read_header /home/user/linux/tools/perf/util/header.c:3886:2
    #6 0x8ec714 in perf_session__open /home/user/linux/tools/perf/util/session.c:109:6
    #7 0x8ebe83 in perf_session__new /home/user/linux/tools/perf/util/session.c:213:10
    #8 0x60c6de in cmd_script /home/user/linux/tools/perf/builtin-script.c:3856:12
    #9 0x7b2930 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
    #10 0x7b120f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
    #11 0x7b2493 in run_argv /home/user/linux/tools/perf/perf.c:409:2
    #12 0x7b0c89 in main /home/user/linux/tools/perf/perf.c:539:3
    #13 0x7f5260654b74  (/lib64/libc.so.6+0x27b74)

SUMMARY: AddressSanitizer: 3728 byte(s) leaked in 7 allocation(s).

Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210624231926.212208-1-rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: stable@vger.kernel.org # 5.10.228
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Dec 8, 2024
[ Upstream commit 3f23f96 ]

BUG: KASAN: slab-use-after-free in tcp_write_timer_handler+0x156/0x3e0
Read of size 1 at addr ffff888111f322cd by task swapper/0/0

CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc4-dirty #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1
Call Trace:
 <IRQ>
 dump_stack_lvl+0x68/0xa0
 print_address_description.constprop.0+0x2c/0x3d0
 print_report+0xb4/0x270
 kasan_report+0xbd/0xf0
 tcp_write_timer_handler+0x156/0x3e0
 tcp_write_timer+0x66/0x170
 call_timer_fn+0xfb/0x1d0
 __run_timers+0x3f8/0x480
 run_timer_softirq+0x9b/0x100
 handle_softirqs+0x153/0x390
 __irq_exit_rcu+0x103/0x120
 irq_exit_rcu+0xe/0x20
 sysvec_apic_timer_interrupt+0x76/0x90
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:default_idle+0xf/0x20
Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90
 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 f8 25 00 fb f4 <fa> c3 cc cc cc
 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffffffa2007e28 EFLAGS: 00000242
RAX: 00000000000f3b31 RBX: 1ffffffff4400fc7 RCX: ffffffffa09c3196
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9f00590f
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed102360835d
R10: ffff88811b041aeb R11: 0000000000000001 R12: 0000000000000000
R13: ffffffffa202d7c0 R14: 0000000000000000 R15: 00000000000147d0
 default_idle_call+0x6b/0xa0
 cpuidle_idle_call+0x1af/0x1f0
 do_idle+0xbc/0x130
 cpu_startup_entry+0x33/0x40
 rest_init+0x11f/0x210
 start_kernel+0x39a/0x420
 x86_64_start_reservations+0x18/0x30
 x86_64_start_kernel+0x97/0xa0
 common_startup_64+0x13e/0x141
 </TASK>

Allocated by task 595:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 __kasan_slab_alloc+0x87/0x90
 kmem_cache_alloc_noprof+0x12b/0x3f0
 copy_net_ns+0x94/0x380
 create_new_namespaces+0x24c/0x500
 unshare_nsproxy_namespaces+0x75/0xf0
 ksys_unshare+0x24e/0x4f0
 __x64_sys_unshare+0x1f/0x30
 do_syscall_64+0x70/0x180
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 100:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3b/0x60
 __kasan_slab_free+0x54/0x70
 kmem_cache_free+0x156/0x5d0
 cleanup_net+0x5d3/0x670
 process_one_work+0x776/0xa90
 worker_thread+0x2e2/0x560
 kthread+0x1a8/0x1f0
 ret_from_fork+0x34/0x60
 ret_from_fork_asm+0x1a/0x30

Reproduction script:

mkdir -p /mnt/nfsshare
mkdir -p /mnt/nfs/netns_1
mkfs.ext4 /dev/sdb
mount /dev/sdb /mnt/nfsshare
systemctl restart nfs-server
chmod 777 /mnt/nfsshare
exportfs -i -o rw,no_root_squash *:/mnt/nfsshare

ip netns add netns_1
ip link add name veth_1_peer type veth peer veth_1
ifconfig veth_1_peer 11.11.0.254 up
ip link set veth_1 netns netns_1
ip netns exec netns_1 ifconfig veth_1 11.11.0.1

ip netns exec netns_1 /root/iptables -A OUTPUT -d 11.11.0.254 -p tcp \
	--tcp-flags FIN FIN  -j DROP

(note: In my environment, a DESTROY_CLIENTID operation is always sent
 immediately, breaking the nfs tcp connection.)
ip netns exec netns_1 timeout -s 9 300 mount -t nfs -o proto=tcp,vers=4.1 \
	11.11.0.254:/mnt/nfsshare /mnt/nfs/netns_1

ip netns del netns_1

The reason here is that the tcp socket in netns_1 (nfs side) has been
shutdown and closed (done in xs_destroy), but the FIN message (with ack)
is discarded, and the nfsd side keeps sending retransmission messages.
As a result, when the tcp sock in netns_1 processes the received message,
it sends the message (FIN message) in the sending queue, and the tcp timer
is re-established. When the network namespace is deleted, the net structure
accessed by tcp's timer handler function causes problems.

To fix this problem, let's hold netns refcnt for the tcp kernel socket as
done in other modules. This is an ugly hack which can easily be backported
to earlier kernels. A proper fix which cleans up the interfaces will
follow, but may not be so easy to backport.

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 9, 2024
[ Upstream commit 3f23f96 ]

BUG: KASAN: slab-use-after-free in tcp_write_timer_handler+0x156/0x3e0
Read of size 1 at addr ffff888111f322cd by task swapper/0/0

CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc4-dirty #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1
Call Trace:
 <IRQ>
 dump_stack_lvl+0x68/0xa0
 print_address_description.constprop.0+0x2c/0x3d0
 print_report+0xb4/0x270
 kasan_report+0xbd/0xf0
 tcp_write_timer_handler+0x156/0x3e0
 tcp_write_timer+0x66/0x170
 call_timer_fn+0xfb/0x1d0
 __run_timers+0x3f8/0x480
 run_timer_softirq+0x9b/0x100
 handle_softirqs+0x153/0x390
 __irq_exit_rcu+0x103/0x120
 irq_exit_rcu+0xe/0x20
 sysvec_apic_timer_interrupt+0x76/0x90
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:default_idle+0xf/0x20
Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90
 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 f8 25 00 fb f4 <fa> c3 cc cc cc
 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffffffa2007e28 EFLAGS: 00000242
RAX: 00000000000f3b31 RBX: 1ffffffff4400fc7 RCX: ffffffffa09c3196
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9f00590f
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed102360835d
R10: ffff88811b041aeb R11: 0000000000000001 R12: 0000000000000000
R13: ffffffffa202d7c0 R14: 0000000000000000 R15: 00000000000147d0
 default_idle_call+0x6b/0xa0
 cpuidle_idle_call+0x1af/0x1f0
 do_idle+0xbc/0x130
 cpu_startup_entry+0x33/0x40
 rest_init+0x11f/0x210
 start_kernel+0x39a/0x420
 x86_64_start_reservations+0x18/0x30
 x86_64_start_kernel+0x97/0xa0
 common_startup_64+0x13e/0x141
 </TASK>

Allocated by task 595:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 __kasan_slab_alloc+0x87/0x90
 kmem_cache_alloc_noprof+0x12b/0x3f0
 copy_net_ns+0x94/0x380
 create_new_namespaces+0x24c/0x500
 unshare_nsproxy_namespaces+0x75/0xf0
 ksys_unshare+0x24e/0x4f0
 __x64_sys_unshare+0x1f/0x30
 do_syscall_64+0x70/0x180
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 100:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3b/0x60
 __kasan_slab_free+0x54/0x70
 kmem_cache_free+0x156/0x5d0
 cleanup_net+0x5d3/0x670
 process_one_work+0x776/0xa90
 worker_thread+0x2e2/0x560
 kthread+0x1a8/0x1f0
 ret_from_fork+0x34/0x60
 ret_from_fork_asm+0x1a/0x30

Reproduction script:

mkdir -p /mnt/nfsshare
mkdir -p /mnt/nfs/netns_1
mkfs.ext4 /dev/sdb
mount /dev/sdb /mnt/nfsshare
systemctl restart nfs-server
chmod 777 /mnt/nfsshare
exportfs -i -o rw,no_root_squash *:/mnt/nfsshare

ip netns add netns_1
ip link add name veth_1_peer type veth peer veth_1
ifconfig veth_1_peer 11.11.0.254 up
ip link set veth_1 netns netns_1
ip netns exec netns_1 ifconfig veth_1 11.11.0.1

ip netns exec netns_1 /root/iptables -A OUTPUT -d 11.11.0.254 -p tcp \
	--tcp-flags FIN FIN  -j DROP

(note: In my environment, a DESTROY_CLIENTID operation is always sent
 immediately, breaking the nfs tcp connection.)
ip netns exec netns_1 timeout -s 9 300 mount -t nfs -o proto=tcp,vers=4.1 \
	11.11.0.254:/mnt/nfsshare /mnt/nfs/netns_1

ip netns del netns_1

The reason here is that the tcp socket in netns_1 (nfs side) has been
shutdown and closed (done in xs_destroy), but the FIN message (with ack)
is discarded, and the nfsd side keeps sending retransmission messages.
As a result, when the tcp sock in netns_1 processes the received message,
it sends the message (FIN message) in the sending queue, and the tcp timer
is re-established. When the network namespace is deleted, the net structure
accessed by tcp's timer handler function causes problems.

To fix this problem, let's hold netns refcnt for the tcp kernel socket as
done in other modules. This is an ugly hack which can easily be backported
to earlier kernels. A proper fix which cleans up the interfaces will
follow, but may not be so easy to backport.

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 9, 2024
[ Upstream commit 3f23f96 ]

BUG: KASAN: slab-use-after-free in tcp_write_timer_handler+0x156/0x3e0
Read of size 1 at addr ffff888111f322cd by task swapper/0/0

CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc4-dirty #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1
Call Trace:
 <IRQ>
 dump_stack_lvl+0x68/0xa0
 print_address_description.constprop.0+0x2c/0x3d0
 print_report+0xb4/0x270
 kasan_report+0xbd/0xf0
 tcp_write_timer_handler+0x156/0x3e0
 tcp_write_timer+0x66/0x170
 call_timer_fn+0xfb/0x1d0
 __run_timers+0x3f8/0x480
 run_timer_softirq+0x9b/0x100
 handle_softirqs+0x153/0x390
 __irq_exit_rcu+0x103/0x120
 irq_exit_rcu+0xe/0x20
 sysvec_apic_timer_interrupt+0x76/0x90
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:default_idle+0xf/0x20
Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90
 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 f8 25 00 fb f4 <fa> c3 cc cc cc
 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffffffa2007e28 EFLAGS: 00000242
RAX: 00000000000f3b31 RBX: 1ffffffff4400fc7 RCX: ffffffffa09c3196
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9f00590f
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed102360835d
R10: ffff88811b041aeb R11: 0000000000000001 R12: 0000000000000000
R13: ffffffffa202d7c0 R14: 0000000000000000 R15: 00000000000147d0
 default_idle_call+0x6b/0xa0
 cpuidle_idle_call+0x1af/0x1f0
 do_idle+0xbc/0x130
 cpu_startup_entry+0x33/0x40
 rest_init+0x11f/0x210
 start_kernel+0x39a/0x420
 x86_64_start_reservations+0x18/0x30
 x86_64_start_kernel+0x97/0xa0
 common_startup_64+0x13e/0x141
 </TASK>

Allocated by task 595:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 __kasan_slab_alloc+0x87/0x90
 kmem_cache_alloc_noprof+0x12b/0x3f0
 copy_net_ns+0x94/0x380
 create_new_namespaces+0x24c/0x500
 unshare_nsproxy_namespaces+0x75/0xf0
 ksys_unshare+0x24e/0x4f0
 __x64_sys_unshare+0x1f/0x30
 do_syscall_64+0x70/0x180
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 100:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3b/0x60
 __kasan_slab_free+0x54/0x70
 kmem_cache_free+0x156/0x5d0
 cleanup_net+0x5d3/0x670
 process_one_work+0x776/0xa90
 worker_thread+0x2e2/0x560
 kthread+0x1a8/0x1f0
 ret_from_fork+0x34/0x60
 ret_from_fork_asm+0x1a/0x30

Reproduction script:

mkdir -p /mnt/nfsshare
mkdir -p /mnt/nfs/netns_1
mkfs.ext4 /dev/sdb
mount /dev/sdb /mnt/nfsshare
systemctl restart nfs-server
chmod 777 /mnt/nfsshare
exportfs -i -o rw,no_root_squash *:/mnt/nfsshare

ip netns add netns_1
ip link add name veth_1_peer type veth peer veth_1
ifconfig veth_1_peer 11.11.0.254 up
ip link set veth_1 netns netns_1
ip netns exec netns_1 ifconfig veth_1 11.11.0.1

ip netns exec netns_1 /root/iptables -A OUTPUT -d 11.11.0.254 -p tcp \
	--tcp-flags FIN FIN  -j DROP

(note: In my environment, a DESTROY_CLIENTID operation is always sent
 immediately, breaking the nfs tcp connection.)
ip netns exec netns_1 timeout -s 9 300 mount -t nfs -o proto=tcp,vers=4.1 \
	11.11.0.254:/mnt/nfsshare /mnt/nfs/netns_1

ip netns del netns_1

The reason here is that the tcp socket in netns_1 (nfs side) has been
shutdown and closed (done in xs_destroy), but the FIN message (with ack)
is discarded, and the nfsd side keeps sending retransmission messages.
As a result, when the tcp sock in netns_1 processes the received message,
it sends the message (FIN message) in the sending queue, and the tcp timer
is re-established. When the network namespace is deleted, the net structure
accessed by tcp's timer handler function causes problems.

To fix this problem, let's hold netns refcnt for the tcp kernel socket as
done in other modules. This is an ugly hack which can easily be backported
to earlier kernels. A proper fix which cleans up the interfaces will
follow, but may not be so easy to backport.

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 17, 2024
[ Upstream commit 6a2fa13 ]

syzkaller reported a use-after-free of UDP kernel socket
in cleanup_bearer() without repro. [0][1]

When bearer_disable() calls tipc_udp_disable(), cleanup
of the UDP kernel socket is deferred by work calling
cleanup_bearer().

tipc_net_stop() waits for such works to finish by checking
tipc_net(net)->wq_count.  However, the work decrements the
count too early before releasing the kernel socket,
unblocking cleanup_net() and resulting in use-after-free.

Let's move the decrement after releasing the socket in
cleanup_bearer().

[0]:
ref_tracker: net notrefcnt@000000009b3d1faf has 1/1 users at
     sk_alloc+0x438/0x608
     inet_create+0x4c8/0xcb0
     __sock_create+0x350/0x6b8
     sock_create_kern+0x58/0x78
     udp_sock_create4+0x68/0x398
     udp_sock_create+0x88/0xc8
     tipc_udp_enable+0x5e8/0x848
     __tipc_nl_bearer_enable+0x84c/0xed8
     tipc_nl_bearer_enable+0x38/0x60
     genl_family_rcv_msg_doit+0x170/0x248
     genl_rcv_msg+0x400/0x5b0
     netlink_rcv_skb+0x1dc/0x398
     genl_rcv+0x44/0x68
     netlink_unicast+0x678/0x8b0
     netlink_sendmsg+0x5e4/0x898
     ____sys_sendmsg+0x500/0x830

[1]:
BUG: KMSAN: use-after-free in udp_hashslot include/net/udp.h:85 [inline]
BUG: KMSAN: use-after-free in udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 udp_hashslot include/net/udp.h:85 [inline]
 udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 sk_common_release+0xaf/0x3f0 net/core/sock.c:3820
 inet_release+0x1e0/0x260 net/ipv4/af_inet.c:437
 inet6_release+0x6f/0xd0 net/ipv6/af_inet6.c:489
 __sock_release net/socket.c:658 [inline]
 sock_release+0xa0/0x210 net/socket.c:686
 cleanup_bearer+0x42d/0x4c0 net/tipc/udp_media.c:819
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_free_hook mm/slub.c:2269 [inline]
 slab_free mm/slub.c:4580 [inline]
 kmem_cache_free+0x207/0xc40 mm/slub.c:4682
 net_free net/core/net_namespace.c:454 [inline]
 cleanup_net+0x16f2/0x19d0 net/core/net_namespace.c:647
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.12.0-rc1-00131-gf66ebf37d69c #7 91723d6f74857f70725e1583cba3cf4adc716cfa
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: events cleanup_bearer

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241127050512.28438-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 17, 2024
[ Upstream commit 6a2fa13 ]

syzkaller reported a use-after-free of UDP kernel socket
in cleanup_bearer() without repro. [0][1]

When bearer_disable() calls tipc_udp_disable(), cleanup
of the UDP kernel socket is deferred by work calling
cleanup_bearer().

tipc_net_stop() waits for such works to finish by checking
tipc_net(net)->wq_count.  However, the work decrements the
count too early before releasing the kernel socket,
unblocking cleanup_net() and resulting in use-after-free.

Let's move the decrement after releasing the socket in
cleanup_bearer().

[0]:
ref_tracker: net notrefcnt@000000009b3d1faf has 1/1 users at
     sk_alloc+0x438/0x608
     inet_create+0x4c8/0xcb0
     __sock_create+0x350/0x6b8
     sock_create_kern+0x58/0x78
     udp_sock_create4+0x68/0x398
     udp_sock_create+0x88/0xc8
     tipc_udp_enable+0x5e8/0x848
     __tipc_nl_bearer_enable+0x84c/0xed8
     tipc_nl_bearer_enable+0x38/0x60
     genl_family_rcv_msg_doit+0x170/0x248
     genl_rcv_msg+0x400/0x5b0
     netlink_rcv_skb+0x1dc/0x398
     genl_rcv+0x44/0x68
     netlink_unicast+0x678/0x8b0
     netlink_sendmsg+0x5e4/0x898
     ____sys_sendmsg+0x500/0x830

[1]:
BUG: KMSAN: use-after-free in udp_hashslot include/net/udp.h:85 [inline]
BUG: KMSAN: use-after-free in udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 udp_hashslot include/net/udp.h:85 [inline]
 udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 sk_common_release+0xaf/0x3f0 net/core/sock.c:3820
 inet_release+0x1e0/0x260 net/ipv4/af_inet.c:437
 inet6_release+0x6f/0xd0 net/ipv6/af_inet6.c:489
 __sock_release net/socket.c:658 [inline]
 sock_release+0xa0/0x210 net/socket.c:686
 cleanup_bearer+0x42d/0x4c0 net/tipc/udp_media.c:819
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_free_hook mm/slub.c:2269 [inline]
 slab_free mm/slub.c:4580 [inline]
 kmem_cache_free+0x207/0xc40 mm/slub.c:4682
 net_free net/core/net_namespace.c:454 [inline]
 cleanup_net+0x16f2/0x19d0 net/core/net_namespace.c:647
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.12.0-rc1-00131-gf66ebf37d69c #7 91723d6f74857f70725e1583cba3cf4adc716cfa
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: events cleanup_bearer

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241127050512.28438-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 17, 2024
[ Upstream commit 6a2fa13 ]

syzkaller reported a use-after-free of UDP kernel socket
in cleanup_bearer() without repro. [0][1]

When bearer_disable() calls tipc_udp_disable(), cleanup
of the UDP kernel socket is deferred by work calling
cleanup_bearer().

tipc_net_stop() waits for such works to finish by checking
tipc_net(net)->wq_count.  However, the work decrements the
count too early before releasing the kernel socket,
unblocking cleanup_net() and resulting in use-after-free.

Let's move the decrement after releasing the socket in
cleanup_bearer().

[0]:
ref_tracker: net notrefcnt@000000009b3d1faf has 1/1 users at
     sk_alloc+0x438/0x608
     inet_create+0x4c8/0xcb0
     __sock_create+0x350/0x6b8
     sock_create_kern+0x58/0x78
     udp_sock_create4+0x68/0x398
     udp_sock_create+0x88/0xc8
     tipc_udp_enable+0x5e8/0x848
     __tipc_nl_bearer_enable+0x84c/0xed8
     tipc_nl_bearer_enable+0x38/0x60
     genl_family_rcv_msg_doit+0x170/0x248
     genl_rcv_msg+0x400/0x5b0
     netlink_rcv_skb+0x1dc/0x398
     genl_rcv+0x44/0x68
     netlink_unicast+0x678/0x8b0
     netlink_sendmsg+0x5e4/0x898
     ____sys_sendmsg+0x500/0x830

[1]:
BUG: KMSAN: use-after-free in udp_hashslot include/net/udp.h:85 [inline]
BUG: KMSAN: use-after-free in udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 udp_hashslot include/net/udp.h:85 [inline]
 udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 sk_common_release+0xaf/0x3f0 net/core/sock.c:3820
 inet_release+0x1e0/0x260 net/ipv4/af_inet.c:437
 inet6_release+0x6f/0xd0 net/ipv6/af_inet6.c:489
 __sock_release net/socket.c:658 [inline]
 sock_release+0xa0/0x210 net/socket.c:686
 cleanup_bearer+0x42d/0x4c0 net/tipc/udp_media.c:819
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_free_hook mm/slub.c:2269 [inline]
 slab_free mm/slub.c:4580 [inline]
 kmem_cache_free+0x207/0xc40 mm/slub.c:4682
 net_free net/core/net_namespace.c:454 [inline]
 cleanup_net+0x16f2/0x19d0 net/core/net_namespace.c:647
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.12.0-rc1-00131-gf66ebf37d69c #7 91723d6f74857f70725e1583cba3cf4adc716cfa
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: events cleanup_bearer

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241127050512.28438-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 17, 2024
[ Upstream commit 6a2fa13 ]

syzkaller reported a use-after-free of UDP kernel socket
in cleanup_bearer() without repro. [0][1]

When bearer_disable() calls tipc_udp_disable(), cleanup
of the UDP kernel socket is deferred by work calling
cleanup_bearer().

tipc_net_stop() waits for such works to finish by checking
tipc_net(net)->wq_count.  However, the work decrements the
count too early before releasing the kernel socket,
unblocking cleanup_net() and resulting in use-after-free.

Let's move the decrement after releasing the socket in
cleanup_bearer().

[0]:
ref_tracker: net notrefcnt@000000009b3d1faf has 1/1 users at
     sk_alloc+0x438/0x608
     inet_create+0x4c8/0xcb0
     __sock_create+0x350/0x6b8
     sock_create_kern+0x58/0x78
     udp_sock_create4+0x68/0x398
     udp_sock_create+0x88/0xc8
     tipc_udp_enable+0x5e8/0x848
     __tipc_nl_bearer_enable+0x84c/0xed8
     tipc_nl_bearer_enable+0x38/0x60
     genl_family_rcv_msg_doit+0x170/0x248
     genl_rcv_msg+0x400/0x5b0
     netlink_rcv_skb+0x1dc/0x398
     genl_rcv+0x44/0x68
     netlink_unicast+0x678/0x8b0
     netlink_sendmsg+0x5e4/0x898
     ____sys_sendmsg+0x500/0x830

[1]:
BUG: KMSAN: use-after-free in udp_hashslot include/net/udp.h:85 [inline]
BUG: KMSAN: use-after-free in udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 udp_hashslot include/net/udp.h:85 [inline]
 udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 sk_common_release+0xaf/0x3f0 net/core/sock.c:3820
 inet_release+0x1e0/0x260 net/ipv4/af_inet.c:437
 inet6_release+0x6f/0xd0 net/ipv6/af_inet6.c:489
 __sock_release net/socket.c:658 [inline]
 sock_release+0xa0/0x210 net/socket.c:686
 cleanup_bearer+0x42d/0x4c0 net/tipc/udp_media.c:819
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_free_hook mm/slub.c:2269 [inline]
 slab_free mm/slub.c:4580 [inline]
 kmem_cache_free+0x207/0xc40 mm/slub.c:4682
 net_free net/core/net_namespace.c:454 [inline]
 cleanup_net+0x16f2/0x19d0 net/core/net_namespace.c:647
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.12.0-rc1-00131-gf66ebf37d69c #7 91723d6f74857f70725e1583cba3cf4adc716cfa
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: events cleanup_bearer

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241127050512.28438-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 17, 2024
[ Upstream commit 6a2fa13 ]

syzkaller reported a use-after-free of UDP kernel socket
in cleanup_bearer() without repro. [0][1]

When bearer_disable() calls tipc_udp_disable(), cleanup
of the UDP kernel socket is deferred by work calling
cleanup_bearer().

tipc_net_stop() waits for such works to finish by checking
tipc_net(net)->wq_count.  However, the work decrements the
count too early before releasing the kernel socket,
unblocking cleanup_net() and resulting in use-after-free.

Let's move the decrement after releasing the socket in
cleanup_bearer().

[0]:
ref_tracker: net notrefcnt@000000009b3d1faf has 1/1 users at
     sk_alloc+0x438/0x608
     inet_create+0x4c8/0xcb0
     __sock_create+0x350/0x6b8
     sock_create_kern+0x58/0x78
     udp_sock_create4+0x68/0x398
     udp_sock_create+0x88/0xc8
     tipc_udp_enable+0x5e8/0x848
     __tipc_nl_bearer_enable+0x84c/0xed8
     tipc_nl_bearer_enable+0x38/0x60
     genl_family_rcv_msg_doit+0x170/0x248
     genl_rcv_msg+0x400/0x5b0
     netlink_rcv_skb+0x1dc/0x398
     genl_rcv+0x44/0x68
     netlink_unicast+0x678/0x8b0
     netlink_sendmsg+0x5e4/0x898
     ____sys_sendmsg+0x500/0x830

[1]:
BUG: KMSAN: use-after-free in udp_hashslot include/net/udp.h:85 [inline]
BUG: KMSAN: use-after-free in udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 udp_hashslot include/net/udp.h:85 [inline]
 udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 sk_common_release+0xaf/0x3f0 net/core/sock.c:3820
 inet_release+0x1e0/0x260 net/ipv4/af_inet.c:437
 inet6_release+0x6f/0xd0 net/ipv6/af_inet6.c:489
 __sock_release net/socket.c:658 [inline]
 sock_release+0xa0/0x210 net/socket.c:686
 cleanup_bearer+0x42d/0x4c0 net/tipc/udp_media.c:819
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_free_hook mm/slub.c:2269 [inline]
 slab_free mm/slub.c:4580 [inline]
 kmem_cache_free+0x207/0xc40 mm/slub.c:4682
 net_free net/core/net_namespace.c:454 [inline]
 cleanup_net+0x16f2/0x19d0 net/core/net_namespace.c:647
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.12.0-rc1-00131-gf66ebf37d69c #7 91723d6f74857f70725e1583cba3cf4adc716cfa
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: events cleanup_bearer

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241127050512.28438-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 18, 2024
[ Upstream commit 6a2fa13 ]

syzkaller reported a use-after-free of UDP kernel socket
in cleanup_bearer() without repro. [0][1]

When bearer_disable() calls tipc_udp_disable(), cleanup
of the UDP kernel socket is deferred by work calling
cleanup_bearer().

tipc_net_stop() waits for such works to finish by checking
tipc_net(net)->wq_count.  However, the work decrements the
count too early before releasing the kernel socket,
unblocking cleanup_net() and resulting in use-after-free.

Let's move the decrement after releasing the socket in
cleanup_bearer().

[0]:
ref_tracker: net notrefcnt@000000009b3d1faf has 1/1 users at
     sk_alloc+0x438/0x608
     inet_create+0x4c8/0xcb0
     __sock_create+0x350/0x6b8
     sock_create_kern+0x58/0x78
     udp_sock_create4+0x68/0x398
     udp_sock_create+0x88/0xc8
     tipc_udp_enable+0x5e8/0x848
     __tipc_nl_bearer_enable+0x84c/0xed8
     tipc_nl_bearer_enable+0x38/0x60
     genl_family_rcv_msg_doit+0x170/0x248
     genl_rcv_msg+0x400/0x5b0
     netlink_rcv_skb+0x1dc/0x398
     genl_rcv+0x44/0x68
     netlink_unicast+0x678/0x8b0
     netlink_sendmsg+0x5e4/0x898
     ____sys_sendmsg+0x500/0x830

[1]:
BUG: KMSAN: use-after-free in udp_hashslot include/net/udp.h:85 [inline]
BUG: KMSAN: use-after-free in udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 udp_hashslot include/net/udp.h:85 [inline]
 udp_lib_unhash+0x3b8/0x930 net/ipv4/udp.c:1979
 sk_common_release+0xaf/0x3f0 net/core/sock.c:3820
 inet_release+0x1e0/0x260 net/ipv4/af_inet.c:437
 inet6_release+0x6f/0xd0 net/ipv6/af_inet6.c:489
 __sock_release net/socket.c:658 [inline]
 sock_release+0xa0/0x210 net/socket.c:686
 cleanup_bearer+0x42d/0x4c0 net/tipc/udp_media.c:819
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_free_hook mm/slub.c:2269 [inline]
 slab_free mm/slub.c:4580 [inline]
 kmem_cache_free+0x207/0xc40 mm/slub.c:4682
 net_free net/core/net_namespace.c:454 [inline]
 cleanup_net+0x16f2/0x19d0 net/core/net_namespace.c:647
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xcaf/0x1c90 kernel/workqueue.c:3310
 worker_thread+0xf6c/0x1510 kernel/workqueue.c:3391
 kthread+0x531/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x60/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244

CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.12.0-rc1-00131-gf66ebf37d69c #7 91723d6f74857f70725e1583cba3cf4adc716cfa
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: events cleanup_bearer

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241127050512.28438-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 18, 2024
[ Upstream commit 5858b68 ]

Kernel will hang on destroy admin_q while we create ctrl failed, such
as following calltrace:

PID: 23644    TASK: ff2d52b40f439fc0  CPU: 2    COMMAND: "nvme"
 #0 [ff61d23de260fb78] __schedule at ffffffff8323bc15
 #1 [ff61d23de260fc08] schedule at ffffffff8323c014
 #2 [ff61d23de260fc28] blk_mq_freeze_queue_wait at ffffffff82a3dba1
 #3 [ff61d23de260fc78] blk_freeze_queue at ffffffff82a4113a
 #4 [ff61d23de260fc90] blk_cleanup_queue at ffffffff82a33006
 #5 [ff61d23de260fcb0] nvme_rdma_destroy_admin_queue at ffffffffc12686ce
 #6 [ff61d23de260fcc8] nvme_rdma_setup_ctrl at ffffffffc1268ced
 #7 [ff61d23de260fd28] nvme_rdma_create_ctrl at ffffffffc126919b
 #8 [ff61d23de260fd68] nvmf_dev_write at ffffffffc024f362
 #9 [ff61d23de260fe38] vfs_write at ffffffff827d5f25
    RIP: 00007fda7891d574  RSP: 00007ffe2ef06958  RFLAGS: 00000202
    RAX: ffffffffffffffda  RBX: 000055e8122a4d90  RCX: 00007fda7891d574
    RDX: 000000000000012b  RSI: 000055e8122a4d90  RDI: 0000000000000004
    RBP: 00007ffe2ef079c0   R8: 000000000000012b   R9: 000055e8122a4d90
    R10: 0000000000000000  R11: 0000000000000202  R12: 0000000000000004
    R13: 000055e8122923c0  R14: 000000000000012b  R15: 00007fda78a54500
    ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

This due to we have quiesced admi_q before cancel requests, but forgot
to unquiesce before destroy it, as a result we fail to drain the
pending requests, and hang on blk_mq_freeze_queue_wait() forever. Here
try to reuse nvme_rdma_teardown_admin_queue() to fix this issue and
simplify the code.

Fixes: 958dc1d ("nvme-rdma: add clean action for failed reconnection")
Reported-by: Yingfu.zhou <yingfu.zhou@shopee.com>
Signed-off-by: Chunguang.xu <chunguang.xu@shopee.com>
Signed-off-by: Yue.zhao <yue.zhao@shopee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 19, 2024
[ Upstream commit 88a6e2f ]

Its used from trace__run(), for the 'perf trace' live mode, i.e. its
strace-like, non-perf.data file processing mode, the most common one.

The trace__run() function will set trace->host using machine__new_host()
that is supposed to give a machine instance representing the running
machine, and since we'll use perf_env__arch_strerrno() to get the right
errno -> string table, we need to use machine->env, so initialize it in
machine__new_host().

Before the patch:

  (gdb) run trace --errno-summary -a sleep 1
  <SNIP>
   Summary of events:

   gvfs-afc-volume (3187), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     pselect6               1      0     0.000     0.000     0.000     0.000      0.00%

   GUsbEventThread (3519), 2 events, 0.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                   1      0     0.000     0.000     0.000     0.000      0.00%
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  478		if (env->arch_strerrno == NULL)
  (gdb) bt
  #0  0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
  #1  0x00000000004b75d2 in thread__dump_stats (ttrace=0x14f58f0, trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4673
  #2  0x00000000004b78bf in trace__fprintf_thread (fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>, thread=0x10fa0b0, trace=0x7fffffffa5b0) at builtin-trace.c:4708
  #3  0x00000000004b7ad9 in trace__fprintf_thread_summary (trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4747
  #4  0x00000000004b656e in trace__run (trace=0x7fffffffa5b0, argc=2, argv=0x7fffffffde60) at builtin-trace.c:4456
  #5  0x00000000004ba43e in cmd_trace (argc=2, argv=0x7fffffffde60) at builtin-trace.c:5487
  #6  0x00000000004c0414 in run_builtin (p=0xec3068 <commands+648>, argc=5, argv=0x7fffffffde60) at perf.c:351
  #7  0x00000000004c06bb in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:404
  #8  0x00000000004c0814 in run_argv (argcp=0x7fffffffdc4c, argv=0x7fffffffdc40) at perf.c:448
  #9  0x00000000004c0b5d in main (argc=5, argv=0x7fffffffde60) at perf.c:560
  (gdb)

After:

  root@number:~# perf trace -a --errno-summary sleep 1
  <SNIP>
     pw-data-loop (2685), 1410 events, 16.0%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     epoll_wait           188      0   983.428     0.000     5.231    15.595      8.68%
     ioctl                 94      0     0.811     0.004     0.009     0.016      2.82%
     read                 188      0     0.322     0.001     0.002     0.006      5.15%
     write                141      0     0.280     0.001     0.002     0.018      8.39%
     timerfd_settime       94      0     0.138     0.001     0.001     0.007      6.47%

   gnome-control-c (179406), 1848 events, 20.9%

     syscall            calls  errors  total       min       avg       max       stddev
                                       (msec)    (msec)    (msec)    (msec)        (%)
     --------------- --------  ------ -------- --------- --------- ---------     ------
     poll                 222      0   959.577     0.000     4.322    21.414     11.40%
     recvmsg              150      0     0.539     0.001     0.004     0.013      5.12%
     write                300      0     0.442     0.001     0.001     0.007      3.29%
     read                 150      0     0.183     0.001     0.001     0.009      5.53%
     getpid               102      0     0.101     0.000     0.001     0.008      7.82%

  root@number:~#

Fixes: 54373b5 ("perf env: Introduce perf_env__arch_strerrno()")
Reported-by: Veronika Molnarova <vmolnaro@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Veronika Molnarova <vmolnaro@redhat.com>
Acked-by: Michael Petlan <mpetlan@redhat.com>
Tested-by: Michael Petlan <mpetlan@redhat.com>
Link: https://lore.kernel.org/r/Z0XffUgNSv_9OjOi@x1
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Dec 19, 2024
[ Upstream commit 24c6843 ]

The 5760X (P7) chip's HW GRO/LRO interface is very similar to that of
the previous generation (5750X or P5).  However, the aggregation ID
fields in the completion structures on P7 have been redefined from
16 bits to 12 bits.  The freed up 4 bits are redefined for part of the
metadata such as the VLAN ID.  The aggregation ID mask was not modified
when adding support for P7 chips.  Including the extra 4 bits for the
aggregation ID can potentially cause the driver to store or fetch the
packet header of GRO/LRO packets in the wrong TPA buffer.  It may hit
the BUG() condition in __skb_pull() because the SKB contains no valid
packet header:

kernel BUG at include/linux/skbuff.h:2766!
Oops: invalid opcode: 0000 1 PREEMPT SMP NOPTI
CPU: 4 UID: 0 PID: 0 Comm: swapper/4 Kdump: loaded Tainted: G           OE      6.12.0-rc2+ #7
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Dell Inc. PowerEdge R760/0VRV9X, BIOS 1.0.1 12/27/2022
RIP: 0010:eth_type_trans+0xda/0x140
Code: 80 00 00 00 eb c1 8b 47 70 2b 47 74 48 8b 97 d0 00 00 00 83 f8 01 7e 1b 48 85 d2 74 06 66 83 3a ff 74 09 b8 00 04 00 00 eb a5 <0f> 0b b8 00 01 00 00 eb 9c 48 85 ff 74 eb 31 f6 b9 02 00 00 00 48
RSP: 0018:ff615003803fcc28 EFLAGS: 00010283
RAX: 00000000000022d2 RBX: 0000000000000003 RCX: ff2e8c25da334040
RDX: 0000000000000040 RSI: ff2e8c25c1ce8000 RDI: ff2e8c25869f9000
RBP: ff2e8c258c31c000 R08: ff2e8c25da334000 R09: 0000000000000001
R10: ff2e8c25da3342c0 R11: ff2e8c25c1ce89c0 R12: ff2e8c258e0990b0
R13: ff2e8c25bb120000 R14: ff2e8c25c1ce89c0 R15: ff2e8c25869f9000
FS:  0000000000000000(0000) GS:ff2e8c34be300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f05317e4c8 CR3: 000000108bac6006 CR4: 0000000000773ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <IRQ>
 ? die+0x33/0x90
 ? do_trap+0xd9/0x100
 ? eth_type_trans+0xda/0x140
 ? do_error_trap+0x65/0x80
 ? eth_type_trans+0xda/0x140
 ? exc_invalid_op+0x4e/0x70
 ? eth_type_trans+0xda/0x140
 ? asm_exc_invalid_op+0x16/0x20
 ? eth_type_trans+0xda/0x140
 bnxt_tpa_end+0x10b/0x6b0 [bnxt_en]
 ? bnxt_tpa_start+0x195/0x320 [bnxt_en]
 bnxt_rx_pkt+0x902/0xd90 [bnxt_en]
 ? __bnxt_tx_int.constprop.0+0x89/0x300 [bnxt_en]
 ? kmem_cache_free+0x343/0x440
 ? __bnxt_tx_int.constprop.0+0x24f/0x300 [bnxt_en]
 __bnxt_poll_work+0x193/0x370 [bnxt_en]
 bnxt_poll_p5+0x9a/0x300 [bnxt_en]
 ? try_to_wake_up+0x209/0x670
 __napi_poll+0x29/0x1b0

Fix it by redefining the aggregation ID mask for P5_PLUS chips to be
12 bits.  This will work because the maximum aggregation ID is less
than 4096 on all P5_PLUS chips.

Fixes: 13d2d3d ("bnxt_en: Add new P7 hardware interface definitions")
Reviewed-by: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241209015448.1937766-1-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Jan 9, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20241130164346.436469-1-snishika@redhat.com
Link: https://lkml.kernel.org/r/20241130161236.433747-2-snishika@redhat.com
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <snishika@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Jan 9, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20241130164346.436469-1-snishika@redhat.com
Link: https://lkml.kernel.org/r/20241130161236.433747-2-snishika@redhat.com
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <snishika@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Jan 10, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20241130164346.436469-1-snishika@redhat.com
Link: https://lkml.kernel.org/r/20241130161236.433747-2-snishika@redhat.com
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <snishika@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Jan 10, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20241130164346.436469-1-snishika@redhat.com
Link: https://lkml.kernel.org/r/20241130161236.433747-2-snishika@redhat.com
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <snishika@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Jan 10, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20241130164346.436469-1-snishika@redhat.com
Link: https://lkml.kernel.org/r/20241130161236.433747-2-snishika@redhat.com
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <snishika@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Jan 10, 2025
…le_direct_reclaim()

commit 6aaced5 upstream.

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20241130164346.436469-1-snishika@redhat.com
Link: https://lkml.kernel.org/r/20241130161236.433747-2-snishika@redhat.com
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <snishika@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Jan 10, 2025
commit 59d9094 upstream.

The folio refcount may be increased unexpectly through try_get_folio() by
caller such as split_huge_pages.  In huge_pmd_unshare(), we use refcount
to check whether a pmd page table is shared.  The check is incorrect if
the refcount is increased by the above caller, and this can cause the page
table leaked:

 BUG: Bad page state in process sh  pfn:109324
 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x66 pfn:0x109324
 flags: 0x17ffff800000000(node=0|zone=2|lastcpupid=0xfffff)
 page_type: f2(table)
 raw: 017ffff800000000 0000000000000000 0000000000000000 0000000000000000
 raw: 0000000000000066 0000000000000000 00000000f2000000 0000000000000000
 page dumped because: nonzero mapcount
 ...
 CPU: 31 UID: 0 PID: 7515 Comm: sh Kdump: loaded Tainted: G    B              6.13.0-rc2master+ #7
 Tainted: [B]=BAD_PAGE
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 Call trace:
  show_stack+0x20/0x38 (C)
  dump_stack_lvl+0x80/0xf8
  dump_stack+0x18/0x28
  bad_page+0x8c/0x130
  free_page_is_bad_report+0xa4/0xb0
  free_unref_page+0x3cc/0x620
  __folio_put+0xf4/0x158
  split_huge_pages_all+0x1e0/0x3e8
  split_huge_pages_write+0x25c/0x2d8
  full_proxy_write+0x64/0xd8
  vfs_write+0xcc/0x280
  ksys_write+0x70/0x110
  __arm64_sys_write+0x24/0x38
  invoke_syscall+0x50/0x120
  el0_svc_common.constprop.0+0xc8/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x34/0x128
  el0t_64_sync_handler+0xc8/0xd0
  el0t_64_sync+0x190/0x198

The issue may be triggered by damon, offline_page, page_idle, etc, which
will increase the refcount of page table.

1. The page table itself will be discarded after reporting the
   "nonzero mapcount".

2. The HugeTLB page mapped by the page table miss freeing since we
   treat the page table as shared and a shared page table will not be
   unmapped.

Fix it by introducing independent PMD page table shared count.  As
described by comment, pt_index/pt_mm/pt_frag_refcount are used for s390
gmap, x86 pgds and powerpc, pt_share_count is used for x86/arm64/riscv
pmds, so we can reuse the field as pt_share_count.

Link: https://lkml.kernel.org/r/20241216071147.3984217-1-liushixin2@huawei.com
Fixes: 39dde65 ("[PATCH] shared page table for hugetlb page")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Ken Chen <kenneth.w.chen@intel.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
anthraxx pushed a commit that referenced this issue Jan 23, 2025
[ Upstream commit 59d9094 ]

The folio refcount may be increased unexpectly through try_get_folio() by
caller such as split_huge_pages.  In huge_pmd_unshare(), we use refcount
to check whether a pmd page table is shared.  The check is incorrect if
the refcount is increased by the above caller, and this can cause the page
table leaked:

 BUG: Bad page state in process sh  pfn:109324
 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x66 pfn:0x109324
 flags: 0x17ffff800000000(node=0|zone=2|lastcpupid=0xfffff)
 page_type: f2(table)
 raw: 017ffff800000000 0000000000000000 0000000000000000 0000000000000000
 raw: 0000000000000066 0000000000000000 00000000f2000000 0000000000000000
 page dumped because: nonzero mapcount
 ...
 CPU: 31 UID: 0 PID: 7515 Comm: sh Kdump: loaded Tainted: G    B              6.13.0-rc2master+ #7
 Tainted: [B]=BAD_PAGE
 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
 Call trace:
  show_stack+0x20/0x38 (C)
  dump_stack_lvl+0x80/0xf8
  dump_stack+0x18/0x28
  bad_page+0x8c/0x130
  free_page_is_bad_report+0xa4/0xb0
  free_unref_page+0x3cc/0x620
  __folio_put+0xf4/0x158
  split_huge_pages_all+0x1e0/0x3e8
  split_huge_pages_write+0x25c/0x2d8
  full_proxy_write+0x64/0xd8
  vfs_write+0xcc/0x280
  ksys_write+0x70/0x110
  __arm64_sys_write+0x24/0x38
  invoke_syscall+0x50/0x120
  el0_svc_common.constprop.0+0xc8/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x34/0x128
  el0t_64_sync_handler+0xc8/0xd0
  el0t_64_sync+0x190/0x198

The issue may be triggered by damon, offline_page, page_idle, etc, which
will increase the refcount of page table.

1. The page table itself will be discarded after reporting the
   "nonzero mapcount".

2. The HugeTLB page mapped by the page table miss freeing since we
   treat the page table as shared and a shared page table will not be
   unmapped.

Fix it by introducing independent PMD page table shared count.  As
described by comment, pt_index/pt_mm/pt_frag_refcount are used for s390
gmap, x86 pgds and powerpc, pt_share_count is used for x86/arm64/riscv
pmds, so we can reuse the field as pt_share_count.

Link: https://lkml.kernel.org/r/20241216071147.3984217-1-liushixin2@huawei.com
Fixes: 39dde65 ("[PATCH] shared page table for hugetlb page")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Ken Chen <kenneth.w.chen@intel.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Mar 1, 2025
[ Upstream commit c7b87ce0dd10b64b68a0b22cb83bbd556e28fe81 ]

libtraceevent parses and returns an array of argument fields, sometimes
larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr",
idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6
elements max, creating an out-of-bounds access. This runtime error is
found by UBsan. The error message:

  $ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1
  builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]'
    #0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966
    #1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110
    #2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436
    #3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897
    #4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335
    #5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502
    #6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351
    #7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404
    #8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448
    #9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556
    #10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360
    #12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6)

     0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1)                                      = 1

Fixes: 5e58fcf ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint")
Signed-off-by: Howard Chu <howardchu95@gmail.com>
Link: https://lore.kernel.org/r/20250122025519.361873-1-howardchu95@gmail.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Mar 1, 2025
[ Upstream commit c7b87ce0dd10b64b68a0b22cb83bbd556e28fe81 ]

libtraceevent parses and returns an array of argument fields, sometimes
larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr",
idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6
elements max, creating an out-of-bounds access. This runtime error is
found by UBsan. The error message:

  $ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1
  builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]'
    #0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966
    #1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110
    #2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436
    #3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897
    #4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335
    #5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502
    #6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351
    #7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404
    #8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448
    #9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556
    #10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360
    #12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6)

     0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1)                                      = 1

Fixes: 5e58fcf ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint")
Signed-off-by: Howard Chu <howardchu95@gmail.com>
Link: https://lore.kernel.org/r/20250122025519.361873-1-howardchu95@gmail.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Mar 1, 2025
[ Upstream commit 2c2ebb2b49573e5f8726112ad06b1dffc3c9ea03 ]

Fix the suspend/resume path by ensuring the rtnl lock is held where
required. Calls to ravb_open, ravb_close and wol operations must be
performed under the rtnl lock to prevent conflicts with ongoing ndo
operations.

Without this fix, the following warning is triggered:
[   39.032969] =============================
[   39.032983] WARNING: suspicious RCU usage
[   39.033019] -----------------------------
[   39.033033] drivers/net/phy/phy_device.c:2004 suspicious
rcu_dereference_protected() usage!
...
[   39.033597] stack backtrace:
[   39.033613] CPU: 0 UID: 0 PID: 174 Comm: python3 Not tainted
6.13.0-rc7-next-20250116-arm64-renesas-00002-g35245dfdc62c #7
[   39.033623] Hardware name: Renesas SMARC EVK version 2 based on
r9a08g045s33 (DT)
[   39.033628] Call trace:
[   39.033633]  show_stack+0x14/0x1c (C)
[   39.033652]  dump_stack_lvl+0xb4/0xc4
[   39.033664]  dump_stack+0x14/0x1c
[   39.033671]  lockdep_rcu_suspicious+0x16c/0x22c
[   39.033682]  phy_detach+0x160/0x190
[   39.033694]  phy_disconnect+0x40/0x54
[   39.033703]  ravb_close+0x6c/0x1cc
[   39.033714]  ravb_suspend+0x48/0x120
[   39.033721]  dpm_run_callback+0x4c/0x14c
[   39.033731]  device_suspend+0x11c/0x4dc
[   39.033740]  dpm_suspend+0xdc/0x214
[   39.033748]  dpm_suspend_start+0x48/0x60
[   39.033758]  suspend_devices_and_enter+0x124/0x574
[   39.033769]  pm_suspend+0x1ac/0x274
[   39.033778]  state_store+0x88/0x124
[   39.033788]  kobj_attr_store+0x14/0x24
[   39.033798]  sysfs_kf_write+0x48/0x6c
[   39.033808]  kernfs_fop_write_iter+0x118/0x1a8
[   39.033817]  vfs_write+0x27c/0x378
[   39.033825]  ksys_write+0x64/0xf4
[   39.033833]  __arm64_sys_write+0x18/0x20
[   39.033841]  invoke_syscall+0x44/0x104
[   39.033852]  el0_svc_common.constprop.0+0xb4/0xd4
[   39.033862]  do_el0_svc+0x18/0x20
[   39.033870]  el0_svc+0x3c/0xf0
[   39.033880]  el0t_64_sync_handler+0xc0/0xc4
[   39.033888]  el0t_64_sync+0x154/0x158
[   39.041274] ravb 11c30000.ethernet eth0: Link is Down

Reported-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@tuxon.dev/
Fixes: 0184165 ("ravb: add sleep PM suspend/resume support")
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Mar 1, 2025
[ Upstream commit c7b87ce0dd10b64b68a0b22cb83bbd556e28fe81 ]

libtraceevent parses and returns an array of argument fields, sometimes
larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr",
idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6
elements max, creating an out-of-bounds access. This runtime error is
found by UBsan. The error message:

  $ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1
  builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]'
    #0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966
    #1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110
    #2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436
    #3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897
    #4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335
    #5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502
    #6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351
    #7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404
    #8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448
    #9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556
    #10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360
    #12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6)

     0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1)                                      = 1

Fixes: 5e58fcf ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint")
Signed-off-by: Howard Chu <howardchu95@gmail.com>
Link: https://lore.kernel.org/r/20250122025519.361873-1-howardchu95@gmail.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Mar 1, 2025
[ Upstream commit 2c2ebb2b49573e5f8726112ad06b1dffc3c9ea03 ]

Fix the suspend/resume path by ensuring the rtnl lock is held where
required. Calls to ravb_open, ravb_close and wol operations must be
performed under the rtnl lock to prevent conflicts with ongoing ndo
operations.

Without this fix, the following warning is triggered:
[   39.032969] =============================
[   39.032983] WARNING: suspicious RCU usage
[   39.033019] -----------------------------
[   39.033033] drivers/net/phy/phy_device.c:2004 suspicious
rcu_dereference_protected() usage!
...
[   39.033597] stack backtrace:
[   39.033613] CPU: 0 UID: 0 PID: 174 Comm: python3 Not tainted
6.13.0-rc7-next-20250116-arm64-renesas-00002-g35245dfdc62c #7
[   39.033623] Hardware name: Renesas SMARC EVK version 2 based on
r9a08g045s33 (DT)
[   39.033628] Call trace:
[   39.033633]  show_stack+0x14/0x1c (C)
[   39.033652]  dump_stack_lvl+0xb4/0xc4
[   39.033664]  dump_stack+0x14/0x1c
[   39.033671]  lockdep_rcu_suspicious+0x16c/0x22c
[   39.033682]  phy_detach+0x160/0x190
[   39.033694]  phy_disconnect+0x40/0x54
[   39.033703]  ravb_close+0x6c/0x1cc
[   39.033714]  ravb_suspend+0x48/0x120
[   39.033721]  dpm_run_callback+0x4c/0x14c
[   39.033731]  device_suspend+0x11c/0x4dc
[   39.033740]  dpm_suspend+0xdc/0x214
[   39.033748]  dpm_suspend_start+0x48/0x60
[   39.033758]  suspend_devices_and_enter+0x124/0x574
[   39.033769]  pm_suspend+0x1ac/0x274
[   39.033778]  state_store+0x88/0x124
[   39.033788]  kobj_attr_store+0x14/0x24
[   39.033798]  sysfs_kf_write+0x48/0x6c
[   39.033808]  kernfs_fop_write_iter+0x118/0x1a8
[   39.033817]  vfs_write+0x27c/0x378
[   39.033825]  ksys_write+0x64/0xf4
[   39.033833]  __arm64_sys_write+0x18/0x20
[   39.033841]  invoke_syscall+0x44/0x104
[   39.033852]  el0_svc_common.constprop.0+0xb4/0xd4
[   39.033862]  do_el0_svc+0x18/0x20
[   39.033870]  el0_svc+0x3c/0xf0
[   39.033880]  el0t_64_sync_handler+0xc0/0xc4
[   39.033888]  el0t_64_sync+0x154/0x158
[   39.041274] ravb 11c30000.ethernet eth0: Link is Down

Reported-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Closes: https://lore.kernel.org/netdev/4c6419d8-c06b-495c-b987-d66c2e1ff848@tuxon.dev/
Fixes: 0184165 ("ravb: add sleep PM suspend/resume support")
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
anthraxx pushed a commit that referenced this issue Mar 1, 2025
[ Upstream commit a216542027b892e6651c1b4e076012140d04afaf ]

When COWing a relocation tree path, at relocation.c:replace_path(), we
can trigger a lockdep splat while we are in the btrfs_search_slot() call
against the relocation root. This happens in that callchain at
ctree.c:read_block_for_search() when we happen to find a child extent
buffer already loaded through the fs tree with a lockdep class set to
the fs tree. So when we attempt to lock that extent buffer through a
relocation tree we have to reset the lockdep class to the class for a
relocation tree, since a relocation tree has extent buffers that used
to belong to a fs tree and may currently be already loaded (we swap
extent buffers between the two trees at the end of replace_path()).

However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset
the lockdep class at ctree.c:read_block_for_search() before we read lock
an extent buffer, just like we did for btrfs_search_slot() in commit
b40130b ("btrfs: fix lockdep splat with reloc root extent buffers").

So add the missing btrfs_maybe_reset_lockdep_class() calls before the
attempts to read lock an extent buffer at ctree.c:read_block_for_search().

The lockdep splat was reported by syzbot and it looks like this:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted
   ------------------------------------------------------
   syz.0.0/5335 is trying to acquire lock:
   ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

   but task is already holding lock:
   ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #2 (btrfs-treloc-02/1){+.+.}-{4:4}:
          reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
          __lock_release kernel/locking/lockdep.c:5563 [inline]
          lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
          up_write+0x79/0x590 kernel/locking/rwsem.c:1629
          btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #1 (btrfs-tree-01/1){+.+.}-{4:4}:
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
          btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
          btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline]
          btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132
          btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351
          btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline]
          btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330
          btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline]
          btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374
          vfs_rename+0xbdb/0xf00 fs/namei.c:5067
          do_renameat2+0xd94/0x13f0 fs/namei.c:5224
          __do_sys_renameat2 fs/namei.c:5258 [inline]
          __se_sys_renameat2 fs/namei.c:5255 [inline]
          __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #0 (btrfs-tree-01){++++}-{4:4}:
          check_prev_add kernel/locking/lockdep.c:3161 [inline]
          check_prevs_add kernel/locking/lockdep.c:3280 [inline]
          validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
          __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
          btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
          btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
          read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
          btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   other info that might help us debug this:

   Chain exists of:
     btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(btrfs-treloc-02/1);
                                  lock(btrfs-tree-01/1);
                                  lock(btrfs-treloc-02/1);
     rlock(btrfs-tree-01);

    *** DEADLOCK ***

   8 locks held by syz.0.0/5335:
    #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
    #1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183
    #2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086
    #3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659
    #4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
    #7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   stack backtrace:
   CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
    check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
    check_prev_add kernel/locking/lockdep.c:3161 [inline]
    check_prevs_add kernel/locking/lockdep.c:3280 [inline]
    validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
    __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
    down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
    btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
    btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
    read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
    btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
    replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
    merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
    merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
    relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1ac6985d29
   Code: ff ff c3 (...)
   RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007
   RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88
    </TASK>

Reported-by: syzbot+63913e558c084f7f8fdc@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/677b3014.050a0220.3b53b0.0064.GAE@google.com/
Fixes: 9978599 ("btrfs: reduce lock contention when eb cache miss for btree search")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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