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gregkh pushed a commit that referenced this pull request Jul 25, 2020
commit 311eab8 upstream.

devm_gpiod_get_index() doesn't return NULL but -ENOENT when the
requested GPIO doesn't exist,  leading to the following messages:

[    2.742468] gpiod_direction_input: invalid GPIO (errorpointer)
[    2.748147] can't set direction for gpio #2: -2
[    2.753081] gpiod_direction_input: invalid GPIO (errorpointer)
[    2.758724] can't set direction for gpio #3: -2
[    2.763666] gpiod_direction_output: invalid GPIO (errorpointer)
[    2.769394] can't set direction for gpio #4: -2
[    2.774341] gpiod_direction_input: invalid GPIO (errorpointer)
[    2.779981] can't set direction for gpio #5: -2
[    2.784545] ff000a20.serial: ttyCPM1 at MMIO 0xfff00a20 (irq = 39, base_baud = 8250000) is a CPM UART

Use devm_gpiod_get_index_optional() instead.

At the same time, handle the error case and properly exit
with an error.

Fixes: 97cbaf2 ("tty: serial: cpm_uart: Convert to use GPIO descriptors")
Cc: stable@vger.kernel.org
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/694a25fdce548c5ee8b060ef6a4b02746b8f25c0.1591986307.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jul 25, 2020
devm_gpiod_get_index() doesn't return NULL but -ENOENT when the
requested GPIO doesn't exist,  leading to the following messages:

[    2.742468] gpiod_direction_input: invalid GPIO (errorpointer)
[    2.748147] can't set direction for gpio #2: -2
[    2.753081] gpiod_direction_input: invalid GPIO (errorpointer)
[    2.758724] can't set direction for gpio #3: -2
[    2.763666] gpiod_direction_output: invalid GPIO (errorpointer)
[    2.769394] can't set direction for gpio #4: -2
[    2.774341] gpiod_direction_input: invalid GPIO (errorpointer)
[    2.779981] can't set direction for gpio #5: -2
[    2.784545] ff000a20.serial: ttyCPM1 at MMIO 0xfff00a20 (irq = 39, base_baud = 8250000) is a CPM UART

Use devm_gpiod_get_index_optional() instead.

At the same time, handle the error case and properly exit
with an error.

Fixes: 97cbaf2 ("tty: serial: cpm_uart: Convert to use GPIO descriptors")
Cc: stable@vger.kernel.org
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/694a25fdce548c5ee8b060ef6a4b02746b8f25c0.1591986307.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jul 25, 2020
In pci_disable_sriov(), i.e.,

 # echo 0 > /sys/class/net/enp11s0f1np1/device/sriov_numvfs

iommu_release_device
  iommu_group_remove_device
    arm_smmu_domain_free
      kfree(smmu_domain)

Later,

iommu_release_device
  arm_smmu_release_device
    arm_smmu_detach_dev
      spin_lock_irqsave(&smmu_domain->devices_lock,

would trigger an use-after-free. Fixed it by call
arm_smmu_release_device() first before iommu_group_remove_device().

 BUG: KASAN: use-after-free in __lock_acquire+0x3458/0x4440
  __lock_acquire at kernel/locking/lockdep.c:4250
 Read of size 8 at addr ffff0089df1a6f68 by task bash/3356

 CPU: 5 PID: 3356 Comm: bash Not tainted 5.8.0-rc3-next-20200630 #2
 Hardware name: HPE Apollo 70             /C01_APACHE_MB         , BIOS L50_5.13_1.11 06/18/2019
 Call trace:
  dump_backtrace+0x0/0x398
  show_stack+0x14/0x20
  dump_stack+0x140/0x1b8
  print_address_description.isra.12+0x54/0x4a8
  kasan_report+0x134/0x1b8
  __asan_report_load8_noabort+0x2c/0x50
  __lock_acquire+0x3458/0x4440
  lock_acquire+0x204/0xf10
  _raw_spin_lock_irqsave+0xf8/0x180
  arm_smmu_detach_dev+0xd8/0x4a0
  arm_smmu_detach_dev at drivers/iommu/arm-smmu-v3.c:2776
  arm_smmu_release_device+0xb4/0x1c8
  arm_smmu_disable_pasid at drivers/iommu/arm-smmu-v3.c:2754
  (inlined by) arm_smmu_release_device at drivers/iommu/arm-smmu-v3.c:3000
  iommu_release_device+0xc0/0x178
  iommu_release_device at drivers/iommu/iommu.c:302
  iommu_bus_notifier+0x118/0x160
  notifier_call_chain+0xa4/0x128
  __blocking_notifier_call_chain+0x70/0xa8
  blocking_notifier_call_chain+0x14/0x20
  device_del+0x618/0xa00
  pci_remove_bus_device+0x108/0x2d8
  pci_stop_and_remove_bus_device+0x1c/0x28
  pci_iov_remove_virtfn+0x228/0x368
  sriov_disable+0x8c/0x348
  pci_disable_sriov+0x5c/0x70
  mlx5_core_sriov_configure+0xd8/0x260 [mlx5_core]
  sriov_numvfs_store+0x240/0x318
  dev_attr_store+0x38/0x68
  sysfs_kf_write+0xdc/0x128
  kernfs_fop_write+0x23c/0x448
  __vfs_write+0x54/0xe8
  vfs_write+0x124/0x3f0
  ksys_write+0xe8/0x1b8
  __arm64_sys_write+0x68/0x98
  do_el0_svc+0x124/0x220
  el0_sync_handler+0x260/0x408
  el0_sync+0x140/0x180

 Allocated by task 3356:
  save_stack+0x24/0x50
  __kasan_kmalloc.isra.13+0xc4/0xe0
  kasan_kmalloc+0xc/0x18
  kmem_cache_alloc_trace+0x1ec/0x318
  arm_smmu_domain_alloc+0x54/0x148
  iommu_group_alloc_default_domain+0xc0/0x440
  iommu_probe_device+0x1c0/0x308
  iort_iommu_configure+0x434/0x518
  acpi_dma_configure+0xf0/0x128
  pci_dma_configure+0x114/0x160
  really_probe+0x124/0x6d8
  driver_probe_device+0xc4/0x180
  __device_attach_driver+0x184/0x1e8
  bus_for_each_drv+0x114/0x1a0
  __device_attach+0x19c/0x2a8
  device_attach+0x10/0x18
  pci_bus_add_device+0x70/0xf8
  pci_iov_add_virtfn+0x7b4/0xb40
  sriov_enable+0x5c8/0xc30
  pci_enable_sriov+0x64/0x80
  mlx5_core_sriov_configure+0x58/0x260 [mlx5_core]
  sriov_numvfs_store+0x1c0/0x318
  dev_attr_store+0x38/0x68
  sysfs_kf_write+0xdc/0x128
  kernfs_fop_write+0x23c/0x448
  __vfs_write+0x54/0xe8
  vfs_write+0x124/0x3f0
  ksys_write+0xe8/0x1b8
  __arm64_sys_write+0x68/0x98
  do_el0_svc+0x124/0x220
  el0_sync_handler+0x260/0x408
  el0_sync+0x140/0x180

 Freed by task 3356:
  save_stack+0x24/0x50
  __kasan_slab_free+0x124/0x198
  kasan_slab_free+0x10/0x18
  slab_free_freelist_hook+0x110/0x298
  kfree+0x128/0x668
  arm_smmu_domain_free+0xf4/0x1a0
  iommu_group_release+0xec/0x160
  kobject_put+0xf4/0x238
  kobject_del+0x110/0x190
  kobject_put+0x1e4/0x238
  iommu_group_remove_device+0x394/0x938
  iommu_release_device+0x9c/0x178
  iommu_release_device at drivers/iommu/iommu.c:300
  iommu_bus_notifier+0x118/0x160
  notifier_call_chain+0xa4/0x128
  __blocking_notifier_call_chain+0x70/0xa8
  blocking_notifier_call_chain+0x14/0x20
  device_del+0x618/0xa00
  pci_remove_bus_device+0x108/0x2d8
  pci_stop_and_remove_bus_device+0x1c/0x28
  pci_iov_remove_virtfn+0x228/0x368
  sriov_disable+0x8c/0x348
  pci_disable_sriov+0x5c/0x70
  mlx5_core_sriov_configure+0xd8/0x260 [mlx5_core]
  sriov_numvfs_store+0x240/0x318
  dev_attr_store+0x38/0x68
  sysfs_kf_write+0xdc/0x128
  kernfs_fop_write+0x23c/0x448
  __vfs_write+0x54/0xe8
  vfs_write+0x124/0x3f0
  ksys_write+0xe8/0x1b8
  __arm64_sys_write+0x68/0x98
  do_el0_svc+0x124/0x220
  el0_sync_handler+0x260/0x408
  el0_sync+0x140/0x180

 The buggy address belongs to the object at ffff0089df1a6e00
  which belongs to the cache kmalloc-512 of size 512
 The buggy address is located 360 bytes inside of
  512-byte region [ffff0089df1a6e00, ffff0089df1a7000)
 The buggy address belongs to the page:
 page:ffffffe02257c680 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0089df1a1400
 flags: 0x7ffff800000200(slab)
 raw: 007ffff800000200 ffffffe02246b8c8 ffffffe02257ff88 ffff000000320680
 raw: ffff0089df1a1400 00000000002a000e 00000001ffffffff ffff0089df1a5001
 page dumped because: kasan: bad access detected
 page->mem_cgroup:ffff0089df1a5001

 Memory state around the buggy address:
  ffff0089df1a6e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff0089df1a6e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 >ffff0089df1a6f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                           ^
  ffff0089df1a6f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff0089df1a7000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: a6a4c7e ("iommu: Add probe_device() and release_device() call-backs")
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200704001003.2303-1-cai@lca.pw
Signed-off-by: Joerg Roedel <jroedel@suse.de>
baruchsiach referenced this pull request in siklu/linux Jul 26, 2020
Jakub Sitnicki says:

====================
This patch set prepares ground for link-based multi-prog attachment for
future netns attach types, with BPF_SK_LOOKUP attach type in mind [0].

Two changes are needed in order to attach and run a series of BPF programs:

  1) an bpf_prog_array of programs to run (patch #2), and
  2) a list of attached links to keep track of attachments (patch #3).

Nothing changes for BPF flow_dissector. Just as before only one program can
be attached to netns.

In v3 I've simplified patch #2 that introduces bpf_prog_array to take
advantage of the fact that it will hold at most one program for now.

In particular, I'm no longer using bpf_prog_array_copy. It turned out to be
less suitable for link operations than I thought as it fails to append the
same BPF program.

bpf_prog_array_replace_item is also gone, because we know we always want to
replace the first element in prog_array.

Naturally the code that handles bpf_prog_array will need change once
more when there is a program type that allows multi-prog attachment. But I
feel it will be better to do it gradually and present it together with
tests that actually exercise multi-prog code paths.

[0] https://lore.kernel.org/bpf/20200511185218.1422406-1-jakub@cloudflare.com/

v2 -> v3:
- Don't check if run_array is null in link update callback. (Martin)
- Allow updating the link with the same BPF program. (Andrii)
- Add patch #4 with a test for the above case.
- Kill bpf_prog_array_replace_item. Access the run_array directly.
- Switch from bpf_prog_array_copy() to bpf_prog_array_alloc(1, ...).
- Replace rcu_deref_protected & RCU_INIT_POINTER with rcu_replace_pointer.
- Drop Andrii's Ack from patch #2. Code changed.

v1 -> v2:

- Show with a (void) cast that bpf_prog_array_replace_item() return value
  is ignored on purpose. (Andrii)
- Explain why bpf-cgroup cannot replace programs in bpf_prog_array based
  on bpf_prog pointer comparison in patch #2 description. (Andrii)
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
baruchsiach referenced this pull request in siklu/linux Jul 26, 2020
…kernel/git/kvmarm/kvmarm into kvm-master

KVM/arm fixes for 5.8, take #2

- Make sure a vcpu becoming non-resident doesn't race against the doorbell delivery
- Only advertise pvtime if accounting is enabled
- Return the correct error code if reset fails with SVE
- Make sure that pseudo-NMI functions are annotated as __always_inline
baruchsiach referenced this pull request in siklu/linux Jul 26, 2020
In BRM_status_show(), if the condition "!ioc->is_warpdrive" tested on entry
to the function is true, a "goto out" is called. This results in unlocking
ioc->pci_access_mutex without this mutex lock being taken.  This generates
the following splat:

[ 1148.539883] mpt3sas_cm2: BRM_status_show: BRM attribute is only for warpdrive
[ 1148.547184]
[ 1148.548708] =====================================
[ 1148.553501] WARNING: bad unlock balance detected!
[ 1148.558277] 5.8.0-rc3+ #827 Not tainted
[ 1148.562183] -------------------------------------
[ 1148.566959] cat/5008 is trying to release lock (&ioc->pci_access_mutex) at:
[ 1148.574035] [<ffffffffc070b7a3>] BRM_status_show+0xd3/0x100 [mpt3sas]
[ 1148.580574] but there are no more locks to release!
[ 1148.585524]
[ 1148.585524] other info that might help us debug this:
[ 1148.599624] 3 locks held by cat/5008:
[ 1148.607085]  #0: ffff92aea3e392c0 (&p->lock){+.+.}-{3:3}, at: seq_read+0x34/0x480
[ 1148.618509]  #1: ffff922ef14c4888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x2a/0xb0
[ 1148.630729]  #2: ffff92aedb5d7310 (kn->active#224){.+.+}-{0:0}, at: kernfs_seq_start+0x32/0xb0
[ 1148.643347]
[ 1148.643347] stack backtrace:
[ 1148.655259] CPU: 73 PID: 5008 Comm: cat Not tainted 5.8.0-rc3+ #827
[ 1148.665309] Hardware name: HGST H4060-S/S2600STB, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019
[ 1148.678394] Call Trace:
[ 1148.684750]  dump_stack+0x78/0xa0
[ 1148.691802]  lock_release.cold+0x45/0x4a
[ 1148.699451]  __mutex_unlock_slowpath+0x35/0x270
[ 1148.707675]  BRM_status_show+0xd3/0x100 [mpt3sas]
[ 1148.716092]  dev_attr_show+0x19/0x40
[ 1148.723664]  sysfs_kf_seq_show+0x87/0x100
[ 1148.731193]  seq_read+0xbc/0x480
[ 1148.737882]  vfs_read+0xa0/0x160
[ 1148.744514]  ksys_read+0x58/0xd0
[ 1148.751129]  do_syscall_64+0x4c/0xa0
[ 1148.757941]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1148.766240] RIP: 0033:0x7f1230566542
[ 1148.772957] Code: Bad RIP value.
[ 1148.779206] RSP: 002b:00007ffeac1bcac8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 1148.790063] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f1230566542
[ 1148.800284] RDX: 0000000000020000 RSI: 00007f1223460000 RDI: 0000000000000003
[ 1148.810474] RBP: 00007f1223460000 R08: 00007f122345f010 R09: 0000000000000000
[ 1148.820641] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000
[ 1148.830728] R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000

Fix this by returning immediately instead of jumping to the out label.

Link: https://lore.kernel.org/r/20200701085254.51740-1-damien.lemoal@wdc.com
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
baruchsiach referenced this pull request in siklu/linux Jul 26, 2020
Ido Schimmel says:

====================
mlxsw: Various fixes

Fix two issues found by syzkaller.

Patch #1 removes inappropriate usage of WARN_ON() following memory
allocation failure. Constantly triggered when syzkaller injects faults.

Patch #2 fixes a use-after-free that can be triggered by 'devlink dev
info' following a failed devlink reload.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
[ Upstream commit ab8b65b ]

It is unsafe to traverse kvm->arch.spapr_tce_tables and
stt->iommu_tables without the RCU read lock held. Also, add
cond_resched_rcu() in places with the RCU read lock held that could take
a while to finish.

 arch/powerpc/kvm/book3s_64_vio.c:76 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 no locks held by qemu-kvm/4265.

 stack backtrace:
 CPU: 96 PID: 4265 Comm: qemu-kvm Not tainted 5.7.0-rc4-next-20200508+ gregkh#2
 Call Trace:
 [c000201a8690f720] [c000000000715948] dump_stack+0xfc/0x174 (unreliable)
 [c000201a8690f770] [c0000000001d9470] lockdep_rcu_suspicious+0x140/0x164
 [c000201a8690f7f0] [c008000010b9fb48] kvm_spapr_tce_release_iommu_group+0x1f0/0x220 [kvm]
 [c000201a8690f870] [c008000010b8462c] kvm_spapr_tce_release_vfio_group+0x54/0xb0 [kvm]
 [c000201a8690f8a0] [c008000010b84710] kvm_vfio_destroy+0x88/0x140 [kvm]
 [c000201a8690f8f0] [c008000010b7d488] kvm_put_kvm+0x370/0x600 [kvm]
 [c000201a8690f990] [c008000010b7e3c0] kvm_vm_release+0x38/0x60 [kvm]
 [c000201a8690f9c0] [c0000000005223f4] __fput+0x124/0x330
 [c000201a8690fa20] [c000000000151cd8] task_work_run+0xb8/0x130
 [c000201a8690fa70] [c0000000001197e8] do_exit+0x4e8/0xfa0
 [c000201a8690fb70] [c00000000011a374] do_group_exit+0x64/0xd0
 [c000201a8690fbb0] [c000000000132c90] get_signal+0x1f0/0x1200
 [c000201a8690fcc0] [c000000000020690] do_notify_resume+0x130/0x3c0
 [c000201a8690fda0] [c000000000038d64] syscall_exit_prepare+0x1a4/0x280
 [c000201a8690fe20] [c00000000000c8f8] system_call_common+0xf8/0x278

 ====
 arch/powerpc/kvm/book3s_64_vio.c:368 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 2 locks held by qemu-kvm/4264:
  #0: c000201ae2d000d8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0xdc/0x950 [kvm]
  gregkh#1: c000200c9ed0c468 (&kvm->srcu){....}-{0:0}, at: kvmppc_h_put_tce+0x88/0x340 [kvm]

 ====
 arch/powerpc/kvm/book3s_64_vio.c:108 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by qemu-kvm/4257:
  #0: c000200b1b363a40 (&kv->lock){+.+.}-{3:3}, at: kvm_vfio_set_attr+0x598/0x6c0 [kvm]

 ====
 arch/powerpc/kvm/book3s_64_vio.c:146 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by qemu-kvm/4257:
  #0: c000200b1b363a40 (&kv->lock){+.+.}-{3:3}, at: kvm_vfio_set_attr+0x598/0x6c0 [kvm]

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
[ Upstream commit 027690c ]

I made every global per-network-namespace instead.  But perhaps doing
that to this slab was a step too far.

The kmem_cache_create call in our net init method also seems to be
responsible for this lockdep warning:

[   45.163710] Unable to find swap-space signature
[   45.375718] trinity-c1 (855): attempted to duplicate a private mapping with mremap.  This is not supported.
[   46.055744] futex_wake_op: trinity-c1 tries to shift op by -209; fix this program
[   51.011723]
[   51.013378] ======================================================
[   51.013875] WARNING: possible circular locking dependency detected
[   51.014378] 5.2.0-rc2 gregkh#1 Not tainted
[   51.014672] ------------------------------------------------------
[   51.015182] trinity-c2/886 is trying to acquire lock:
[   51.015593] 000000005405f099 (slab_mutex){+.+.}, at: slab_attr_store+0xa2/0x130
[   51.016190]
[   51.016190] but task is already holding lock:
[   51.016652] 00000000ac662005 (kn->count#43){++++}, at: kernfs_fop_write+0x286/0x500
[   51.017266]
[   51.017266] which lock already depends on the new lock.
[   51.017266]
[   51.017909]
[   51.017909] the existing dependency chain (in reverse order) is:
[   51.018497]
[   51.018497] -> gregkh#1 (kn->count#43){++++}:
[   51.018956]        __lock_acquire+0x7cf/0x1a20
[   51.019317]        lock_acquire+0x17d/0x390
[   51.019658]        __kernfs_remove+0x892/0xae0
[   51.020020]        kernfs_remove_by_name_ns+0x78/0x110
[   51.020435]        sysfs_remove_link+0x55/0xb0
[   51.020832]        sysfs_slab_add+0xc1/0x3e0
[   51.021332]        __kmem_cache_create+0x155/0x200
[   51.021720]        create_cache+0xf5/0x320
[   51.022054]        kmem_cache_create_usercopy+0x179/0x320
[   51.022486]        kmem_cache_create+0x1a/0x30
[   51.022867]        nfsd_reply_cache_init+0x278/0x560
[   51.023266]        nfsd_init_net+0x20f/0x5e0
[   51.023623]        ops_init+0xcb/0x4b0
[   51.023928]        setup_net+0x2fe/0x670
[   51.024315]        copy_net_ns+0x30a/0x3f0
[   51.024653]        create_new_namespaces+0x3c5/0x820
[   51.025257]        unshare_nsproxy_namespaces+0xd1/0x240
[   51.025881]        ksys_unshare+0x506/0x9c0
[   51.026381]        __x64_sys_unshare+0x3a/0x50
[   51.026937]        do_syscall_64+0x110/0x10b0
[   51.027509]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   51.028175]
[   51.028175] -> #0 (slab_mutex){+.+.}:
[   51.028817]        validate_chain+0x1c51/0x2cc0
[   51.029422]        __lock_acquire+0x7cf/0x1a20
[   51.029947]        lock_acquire+0x17d/0x390
[   51.030438]        __mutex_lock+0x100/0xfa0
[   51.030995]        mutex_lock_nested+0x27/0x30
[   51.031516]        slab_attr_store+0xa2/0x130
[   51.032020]        sysfs_kf_write+0x11d/0x180
[   51.032529]        kernfs_fop_write+0x32a/0x500
[   51.033056]        do_loop_readv_writev+0x21d/0x310
[   51.033627]        do_iter_write+0x2e5/0x380
[   51.034148]        vfs_writev+0x170/0x310
[   51.034616]        do_pwritev+0x13e/0x160
[   51.035100]        __x64_sys_pwritev+0xa3/0x110
[   51.035633]        do_syscall_64+0x110/0x10b0
[   51.036200]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   51.036924]
[   51.036924] other info that might help us debug this:
[   51.036924]
[   51.037876]  Possible unsafe locking scenario:
[   51.037876]
[   51.038556]        CPU0                    CPU1
[   51.039130]        ----                    ----
[   51.039676]   lock(kn->count#43);
[   51.040084]                                lock(slab_mutex);
[   51.040597]                                lock(kn->count#43);
[   51.041062]   lock(slab_mutex);
[   51.041320]
[   51.041320]  *** DEADLOCK ***
[   51.041320]
[   51.041793] 3 locks held by trinity-c2/886:
[   51.042128]  #0: 000000001f55e152 (sb_writers#5){.+.+}, at: vfs_writev+0x2b9/0x310
[   51.042739]  gregkh#1: 00000000c7d6c034 (&of->mutex){+.+.}, at: kernfs_fop_write+0x25b/0x500
[   51.043400]  gregkh#2: 00000000ac662005 (kn->count#43){++++}, at: kernfs_fop_write+0x286/0x500

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 3ba7583 "drc containerization"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
[ Upstream commit 2d3a8e2 ]

In blkdev_get() we call __blkdev_get() to do some internal jobs and if
there is some errors in __blkdev_get(), the bdput() is called which
means we have released the refcount of the bdev (actually the refcount of
the bdev inode). This means we cannot access bdev after that point. But
acctually bdev is still accessed in blkdev_get() after calling
__blkdev_get(). This results in use-after-free if the refcount is the
last one we released in __blkdev_get(). Let's take a look at the
following scenerio:

  CPU0            CPU1                    CPU2
blkdev_open     blkdev_open           Remove disk
                  bd_acquire
		  blkdev_get
		    __blkdev_get      del_gendisk
					bdev_unhash_inode
  bd_acquire          bdev_get_gendisk
    bd_forget           failed because of unhashed
	  bdput
	              bdput (the last one)
		        bdev_evict_inode

	  	    access bdev => use after free

[  459.350216] BUG: KASAN: use-after-free in __lock_acquire+0x24c1/0x31b0
[  459.351190] Read of size 8 at addr ffff88806c815a80 by task syz-executor.0/20132
[  459.352347]
[  459.352594] CPU: 0 PID: 20132 Comm: syz-executor.0 Not tainted 4.19.90 gregkh#2
[  459.353628] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[  459.354947] Call Trace:
[  459.355337]  dump_stack+0x111/0x19e
[  459.355879]  ? __lock_acquire+0x24c1/0x31b0
[  459.356523]  print_address_description+0x60/0x223
[  459.357248]  ? __lock_acquire+0x24c1/0x31b0
[  459.357887]  kasan_report.cold+0xae/0x2d8
[  459.358503]  __lock_acquire+0x24c1/0x31b0
[  459.359120]  ? _raw_spin_unlock_irq+0x24/0x40
[  459.359784]  ? lockdep_hardirqs_on+0x37b/0x580
[  459.360465]  ? _raw_spin_unlock_irq+0x24/0x40
[  459.361123]  ? finish_task_switch+0x125/0x600
[  459.361812]  ? finish_task_switch+0xee/0x600
[  459.362471]  ? mark_held_locks+0xf0/0xf0
[  459.363108]  ? __schedule+0x96f/0x21d0
[  459.363716]  lock_acquire+0x111/0x320
[  459.364285]  ? blkdev_get+0xce/0xbe0
[  459.364846]  ? blkdev_get+0xce/0xbe0
[  459.365390]  __mutex_lock+0xf9/0x12a0
[  459.365948]  ? blkdev_get+0xce/0xbe0
[  459.366493]  ? bdev_evict_inode+0x1f0/0x1f0
[  459.367130]  ? blkdev_get+0xce/0xbe0
[  459.367678]  ? destroy_inode+0xbc/0x110
[  459.368261]  ? mutex_trylock+0x1a0/0x1a0
[  459.368867]  ? __blkdev_get+0x3e6/0x1280
[  459.369463]  ? bdev_disk_changed+0x1d0/0x1d0
[  459.370114]  ? blkdev_get+0xce/0xbe0
[  459.370656]  blkdev_get+0xce/0xbe0
[  459.371178]  ? find_held_lock+0x2c/0x110
[  459.371774]  ? __blkdev_get+0x1280/0x1280
[  459.372383]  ? lock_downgrade+0x680/0x680
[  459.373002]  ? lock_acquire+0x111/0x320
[  459.373587]  ? bd_acquire+0x21/0x2c0
[  459.374134]  ? do_raw_spin_unlock+0x4f/0x250
[  459.374780]  blkdev_open+0x202/0x290
[  459.375325]  do_dentry_open+0x49e/0x1050
[  459.375924]  ? blkdev_get_by_dev+0x70/0x70
[  459.376543]  ? __x64_sys_fchdir+0x1f0/0x1f0
[  459.377192]  ? inode_permission+0xbe/0x3a0
[  459.377818]  path_openat+0x148c/0x3f50
[  459.378392]  ? kmem_cache_alloc+0xd5/0x280
[  459.379016]  ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.379802]  ? path_lookupat.isra.0+0x900/0x900
[  459.380489]  ? __lock_is_held+0xad/0x140
[  459.381093]  do_filp_open+0x1a1/0x280
[  459.381654]  ? may_open_dev+0xf0/0xf0
[  459.382214]  ? find_held_lock+0x2c/0x110
[  459.382816]  ? lock_downgrade+0x680/0x680
[  459.383425]  ? __lock_is_held+0xad/0x140
[  459.384024]  ? do_raw_spin_unlock+0x4f/0x250
[  459.384668]  ? _raw_spin_unlock+0x1f/0x30
[  459.385280]  ? __alloc_fd+0x448/0x560
[  459.385841]  do_sys_open+0x3c3/0x500
[  459.386386]  ? filp_open+0x70/0x70
[  459.386911]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[  459.387610]  ? trace_hardirqs_off_caller+0x55/0x1c0
[  459.388342]  ? do_syscall_64+0x1a/0x520
[  459.388930]  do_syscall_64+0xc3/0x520
[  459.389490]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.390248] RIP: 0033:0x416211
[  459.390720] Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83
04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f
   05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d
      01
[  459.393483] RSP: 002b:00007fe45dfe9a60 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
[  459.394610] RAX: ffffffffffffffda RBX: 00007fe45dfea6d4 RCX: 0000000000416211
[  459.395678] RDX: 00007fe45dfe9b0a RSI: 0000000000000002 RDI: 00007fe45dfe9b00
[  459.396758] RBP: 000000000076bf20 R08: 0000000000000000 R09: 000000000000000a
[  459.397930] R10: 0000000000000075 R11: 0000000000000293 R12: 00000000ffffffff
[  459.399022] R13: 0000000000000bd9 R14: 00000000004cdb80 R15: 000000000076bf2c
[  459.400168]
[  459.400430] Allocated by task 20132:
[  459.401038]  kasan_kmalloc+0xbf/0xe0
[  459.401652]  kmem_cache_alloc+0xd5/0x280
[  459.402330]  bdev_alloc_inode+0x18/0x40
[  459.402970]  alloc_inode+0x5f/0x180
[  459.403510]  iget5_locked+0x57/0xd0
[  459.404095]  bdget+0x94/0x4e0
[  459.404607]  bd_acquire+0xfa/0x2c0
[  459.405113]  blkdev_open+0x110/0x290
[  459.405702]  do_dentry_open+0x49e/0x1050
[  459.406340]  path_openat+0x148c/0x3f50
[  459.406926]  do_filp_open+0x1a1/0x280
[  459.407471]  do_sys_open+0x3c3/0x500
[  459.408010]  do_syscall_64+0xc3/0x520
[  459.408572]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.409415]
[  459.409679] Freed by task 1262:
[  459.410212]  __kasan_slab_free+0x129/0x170
[  459.410919]  kmem_cache_free+0xb2/0x2a0
[  459.411564]  rcu_process_callbacks+0xbb2/0x2320
[  459.412318]  __do_softirq+0x225/0x8ac

Fix this by delaying bdput() to the end of blkdev_get() which means we
have finished accessing bdev.

Fixes: 77ea887 ("implement in-kernel gendisk events handling")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
commit e5a15e1 upstream.

The following kernel panic was captured when running nfs server over
ocfs2, at that time ocfs2_test_inode_bit() was checking whether one
inode locating at "blkno" 5 was valid, that is ocfs2 root inode, its
"suballoc_slot" was OCFS2_INVALID_SLOT(65535) and it was allocted from
//global_inode_alloc, but here it wrongly assumed that it was got from per
slot inode alloctor which would cause array overflow and trigger kernel
panic.

  BUG: unable to handle kernel paging request at 0000000000001088
  IP: [<ffffffff816f6898>] _raw_spin_lock+0x18/0xf0
  PGD 1e06ba067 PUD 1e9e7d067 PMD 0
  Oops: 0002 [gregkh#1] SMP
  CPU: 6 PID: 24873 Comm: nfsd Not tainted 4.1.12-124.36.1.el6uek.x86_64 gregkh#2
  Hardware name: Huawei CH121 V3/IT11SGCA1, BIOS 3.87 02/02/2018
  RIP: _raw_spin_lock+0x18/0xf0
  RSP: e02b:ffff88005ae97908  EFLAGS: 00010206
  RAX: ffff88005ae98000 RBX: 0000000000001088 RCX: 0000000000000000
  RDX: 0000000000020000 RSI: 0000000000000009 RDI: 0000000000001088
  RBP: ffff88005ae97928 R08: 0000000000000000 R09: ffff880212878e00
  R10: 0000000000007ff0 R11: 0000000000000000 R12: 0000000000001088
  R13: ffff8800063c0aa8 R14: ffff8800650c27d0 R15: 000000000000ffff
  FS:  0000000000000000(0000) GS:ffff880218180000(0000) knlGS:ffff880218180000
  CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000001088 CR3: 00000002033d0000 CR4: 0000000000042660
  Call Trace:
    igrab+0x1e/0x60
    ocfs2_get_system_file_inode+0x63/0x3a0 [ocfs2]
    ocfs2_test_inode_bit+0x328/0xa00 [ocfs2]
    ocfs2_get_parent+0xba/0x3e0 [ocfs2]
    reconnect_path+0xb5/0x300
    exportfs_decode_fh+0xf6/0x2b0
    fh_verify+0x350/0x660 [nfsd]
    nfsd4_putfh+0x4d/0x60 [nfsd]
    nfsd4_proc_compound+0x3d3/0x6f0 [nfsd]
    nfsd_dispatch+0xe0/0x290 [nfsd]
    svc_process_common+0x412/0x6a0 [sunrpc]
    svc_process+0x123/0x210 [sunrpc]
    nfsd+0xff/0x170 [nfsd]
    kthread+0xcb/0xf0
    ret_from_fork+0x61/0x90
  Code: 83 c2 02 0f b7 f2 e8 18 dc 91 ff 66 90 eb bf 0f 1f 40 00 55 48 89 e5 41 56 41 55 41 54 53 0f 1f 44 00 00 48 89 fb ba 00 00 02 00 <f0> 0f c1 17 89 d0 45 31 e4 45 31 ed c1 e8 10 66 39 d0 41 89 c6
  RIP   _raw_spin_lock+0x18/0xf0
  CR2: 0000000000001088
  ---[ end trace 7264463cd1aac8f9 ]---
  Kernel panic - not syncing: Fatal exception

Link: http://lkml.kernel.org/r/20200616183829.87211-4-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
[ Upstream commit 440ab9e ]

At times when I'm using kgdb I see a splat on my console about
suspicious RCU usage.  I managed to come up with a case that could
reproduce this that looked like this:

  WARNING: suspicious RCU usage
  5.7.0-rc4+ #609 Not tainted
  -----------------------------
  kernel/pid.c:395 find_task_by_pid_ns() needs rcu_read_lock() protection!

  other info that might help us debug this:

    rcu_scheduler_active = 2, debug_locks = 1
  3 locks held by swapper/0/1:
   #0: ffffff81b6b8e988 (&dev->mutex){....}-{3:3}, at: __device_attach+0x40/0x13c
   gregkh#1: ffffffd01109e9e8 (dbg_master_lock){....}-{2:2}, at: kgdb_cpu_enter+0x20c/0x7ac
   gregkh#2: ffffffd01109ea90 (dbg_slave_lock){....}-{2:2}, at: kgdb_cpu_enter+0x3ec/0x7ac

  stack backtrace:
  CPU: 7 PID: 1 Comm: swapper/0 Not tainted 5.7.0-rc4+ #609
  Hardware name: Google Cheza (rev3+) (DT)
  Call trace:
   dump_backtrace+0x0/0x1b8
   show_stack+0x1c/0x24
   dump_stack+0xd4/0x134
   lockdep_rcu_suspicious+0xf0/0x100
   find_task_by_pid_ns+0x5c/0x80
   getthread+0x8c/0xb0
   gdb_serial_stub+0x9d4/0xd04
   kgdb_cpu_enter+0x284/0x7ac
   kgdb_handle_exception+0x174/0x20c
   kgdb_brk_fn+0x24/0x30
   call_break_hook+0x6c/0x7c
   brk_handler+0x20/0x5c
   do_debug_exception+0x1c8/0x22c
   el1_sync_handler+0x3c/0xe4
   el1_sync+0x7c/0x100
   rpmh_rsc_probe+0x38/0x420
   platform_drv_probe+0x94/0xb4
   really_probe+0x134/0x300
   driver_probe_device+0x68/0x100
   __device_attach_driver+0x90/0xa8
   bus_for_each_drv+0x84/0xcc
   __device_attach+0xb4/0x13c
   device_initial_probe+0x18/0x20
   bus_probe_device+0x38/0x98
   device_add+0x38c/0x420

If I understand properly we should just be able to blanket kgdb under
one big RCU read lock and the problem should go away.  We'll add it to
the beast-of-a-function known as kgdb_cpu_enter().

With this I no longer get any splats and things seem to work fine.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200602154729.v2.1.I70e0d4fd46d5ed2aaf0c98a355e8e1b7a5bb7e4e@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
commit 54505a1 upstream.

The commits cd0e00c and 92d7223 broke boot on the Alpha Avanti
platform. The patches move memory barriers after a write before the write.
The result is that if there's iowrite followed by ioread, there is no
barrier between them.

The Alpha architecture allows reordering of the accesses to the I/O space,
and the missing barrier between write and read causes hang with serial
port and real time clock.

This patch makes barriers confiorm to the specification.

1. We add mb() before readX_relaxed and writeX_relaxed -
   memory-barriers.txt claims that these functions must be ordered w.r.t.
   each other. Alpha doesn't order them, so we need an explicit barrier.
2. We add mb() before reads from the I/O space - so that if there's a
   write followed by a read, there should be a barrier between them.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: cd0e00c ("alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering")
Fixes: 92d7223 ("alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering gregkh#2")
Cc: stable@vger.kernel.org      # v4.17+
Acked-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
[ Upstream commit ab8b65b ]

It is unsafe to traverse kvm->arch.spapr_tce_tables and
stt->iommu_tables without the RCU read lock held. Also, add
cond_resched_rcu() in places with the RCU read lock held that could take
a while to finish.

 arch/powerpc/kvm/book3s_64_vio.c:76 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 no locks held by qemu-kvm/4265.

 stack backtrace:
 CPU: 96 PID: 4265 Comm: qemu-kvm Not tainted 5.7.0-rc4-next-20200508+ gregkh#2
 Call Trace:
 [c000201a8690f720] [c000000000715948] dump_stack+0xfc/0x174 (unreliable)
 [c000201a8690f770] [c0000000001d9470] lockdep_rcu_suspicious+0x140/0x164
 [c000201a8690f7f0] [c008000010b9fb48] kvm_spapr_tce_release_iommu_group+0x1f0/0x220 [kvm]
 [c000201a8690f870] [c008000010b8462c] kvm_spapr_tce_release_vfio_group+0x54/0xb0 [kvm]
 [c000201a8690f8a0] [c008000010b84710] kvm_vfio_destroy+0x88/0x140 [kvm]
 [c000201a8690f8f0] [c008000010b7d488] kvm_put_kvm+0x370/0x600 [kvm]
 [c000201a8690f990] [c008000010b7e3c0] kvm_vm_release+0x38/0x60 [kvm]
 [c000201a8690f9c0] [c0000000005223f4] __fput+0x124/0x330
 [c000201a8690fa20] [c000000000151cd8] task_work_run+0xb8/0x130
 [c000201a8690fa70] [c0000000001197e8] do_exit+0x4e8/0xfa0
 [c000201a8690fb70] [c00000000011a374] do_group_exit+0x64/0xd0
 [c000201a8690fbb0] [c000000000132c90] get_signal+0x1f0/0x1200
 [c000201a8690fcc0] [c000000000020690] do_notify_resume+0x130/0x3c0
 [c000201a8690fda0] [c000000000038d64] syscall_exit_prepare+0x1a4/0x280
 [c000201a8690fe20] [c00000000000c8f8] system_call_common+0xf8/0x278

 ====
 arch/powerpc/kvm/book3s_64_vio.c:368 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 2 locks held by qemu-kvm/4264:
  #0: c000201ae2d000d8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0xdc/0x950 [kvm]
  gregkh#1: c000200c9ed0c468 (&kvm->srcu){....}-{0:0}, at: kvmppc_h_put_tce+0x88/0x340 [kvm]

 ====
 arch/powerpc/kvm/book3s_64_vio.c:108 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by qemu-kvm/4257:
  #0: c000200b1b363a40 (&kv->lock){+.+.}-{3:3}, at: kvm_vfio_set_attr+0x598/0x6c0 [kvm]

 ====
 arch/powerpc/kvm/book3s_64_vio.c:146 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by qemu-kvm/4257:
  #0: c000200b1b363a40 (&kv->lock){+.+.}-{3:3}, at: kvm_vfio_set_attr+0x598/0x6c0 [kvm]

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
[ Upstream commit 027690c ]

I made every global per-network-namespace instead.  But perhaps doing
that to this slab was a step too far.

The kmem_cache_create call in our net init method also seems to be
responsible for this lockdep warning:

[   45.163710] Unable to find swap-space signature
[   45.375718] trinity-c1 (855): attempted to duplicate a private mapping with mremap.  This is not supported.
[   46.055744] futex_wake_op: trinity-c1 tries to shift op by -209; fix this program
[   51.011723]
[   51.013378] ======================================================
[   51.013875] WARNING: possible circular locking dependency detected
[   51.014378] 5.2.0-rc2 gregkh#1 Not tainted
[   51.014672] ------------------------------------------------------
[   51.015182] trinity-c2/886 is trying to acquire lock:
[   51.015593] 000000005405f099 (slab_mutex){+.+.}, at: slab_attr_store+0xa2/0x130
[   51.016190]
[   51.016190] but task is already holding lock:
[   51.016652] 00000000ac662005 (kn->count#43){++++}, at: kernfs_fop_write+0x286/0x500
[   51.017266]
[   51.017266] which lock already depends on the new lock.
[   51.017266]
[   51.017909]
[   51.017909] the existing dependency chain (in reverse order) is:
[   51.018497]
[   51.018497] -> gregkh#1 (kn->count#43){++++}:
[   51.018956]        __lock_acquire+0x7cf/0x1a20
[   51.019317]        lock_acquire+0x17d/0x390
[   51.019658]        __kernfs_remove+0x892/0xae0
[   51.020020]        kernfs_remove_by_name_ns+0x78/0x110
[   51.020435]        sysfs_remove_link+0x55/0xb0
[   51.020832]        sysfs_slab_add+0xc1/0x3e0
[   51.021332]        __kmem_cache_create+0x155/0x200
[   51.021720]        create_cache+0xf5/0x320
[   51.022054]        kmem_cache_create_usercopy+0x179/0x320
[   51.022486]        kmem_cache_create+0x1a/0x30
[   51.022867]        nfsd_reply_cache_init+0x278/0x560
[   51.023266]        nfsd_init_net+0x20f/0x5e0
[   51.023623]        ops_init+0xcb/0x4b0
[   51.023928]        setup_net+0x2fe/0x670
[   51.024315]        copy_net_ns+0x30a/0x3f0
[   51.024653]        create_new_namespaces+0x3c5/0x820
[   51.025257]        unshare_nsproxy_namespaces+0xd1/0x240
[   51.025881]        ksys_unshare+0x506/0x9c0
[   51.026381]        __x64_sys_unshare+0x3a/0x50
[   51.026937]        do_syscall_64+0x110/0x10b0
[   51.027509]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   51.028175]
[   51.028175] -> #0 (slab_mutex){+.+.}:
[   51.028817]        validate_chain+0x1c51/0x2cc0
[   51.029422]        __lock_acquire+0x7cf/0x1a20
[   51.029947]        lock_acquire+0x17d/0x390
[   51.030438]        __mutex_lock+0x100/0xfa0
[   51.030995]        mutex_lock_nested+0x27/0x30
[   51.031516]        slab_attr_store+0xa2/0x130
[   51.032020]        sysfs_kf_write+0x11d/0x180
[   51.032529]        kernfs_fop_write+0x32a/0x500
[   51.033056]        do_loop_readv_writev+0x21d/0x310
[   51.033627]        do_iter_write+0x2e5/0x380
[   51.034148]        vfs_writev+0x170/0x310
[   51.034616]        do_pwritev+0x13e/0x160
[   51.035100]        __x64_sys_pwritev+0xa3/0x110
[   51.035633]        do_syscall_64+0x110/0x10b0
[   51.036200]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   51.036924]
[   51.036924] other info that might help us debug this:
[   51.036924]
[   51.037876]  Possible unsafe locking scenario:
[   51.037876]
[   51.038556]        CPU0                    CPU1
[   51.039130]        ----                    ----
[   51.039676]   lock(kn->count#43);
[   51.040084]                                lock(slab_mutex);
[   51.040597]                                lock(kn->count#43);
[   51.041062]   lock(slab_mutex);
[   51.041320]
[   51.041320]  *** DEADLOCK ***
[   51.041320]
[   51.041793] 3 locks held by trinity-c2/886:
[   51.042128]  #0: 000000001f55e152 (sb_writers#5){.+.+}, at: vfs_writev+0x2b9/0x310
[   51.042739]  gregkh#1: 00000000c7d6c034 (&of->mutex){+.+.}, at: kernfs_fop_write+0x25b/0x500
[   51.043400]  gregkh#2: 00000000ac662005 (kn->count#43){++++}, at: kernfs_fop_write+0x286/0x500

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 3ba7583 "drc containerization"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
[ Upstream commit 2d3a8e2 ]

In blkdev_get() we call __blkdev_get() to do some internal jobs and if
there is some errors in __blkdev_get(), the bdput() is called which
means we have released the refcount of the bdev (actually the refcount of
the bdev inode). This means we cannot access bdev after that point. But
acctually bdev is still accessed in blkdev_get() after calling
__blkdev_get(). This results in use-after-free if the refcount is the
last one we released in __blkdev_get(). Let's take a look at the
following scenerio:

  CPU0            CPU1                    CPU2
blkdev_open     blkdev_open           Remove disk
                  bd_acquire
		  blkdev_get
		    __blkdev_get      del_gendisk
					bdev_unhash_inode
  bd_acquire          bdev_get_gendisk
    bd_forget           failed because of unhashed
	  bdput
	              bdput (the last one)
		        bdev_evict_inode

	  	    access bdev => use after free

[  459.350216] BUG: KASAN: use-after-free in __lock_acquire+0x24c1/0x31b0
[  459.351190] Read of size 8 at addr ffff88806c815a80 by task syz-executor.0/20132
[  459.352347]
[  459.352594] CPU: 0 PID: 20132 Comm: syz-executor.0 Not tainted 4.19.90 gregkh#2
[  459.353628] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[  459.354947] Call Trace:
[  459.355337]  dump_stack+0x111/0x19e
[  459.355879]  ? __lock_acquire+0x24c1/0x31b0
[  459.356523]  print_address_description+0x60/0x223
[  459.357248]  ? __lock_acquire+0x24c1/0x31b0
[  459.357887]  kasan_report.cold+0xae/0x2d8
[  459.358503]  __lock_acquire+0x24c1/0x31b0
[  459.359120]  ? _raw_spin_unlock_irq+0x24/0x40
[  459.359784]  ? lockdep_hardirqs_on+0x37b/0x580
[  459.360465]  ? _raw_spin_unlock_irq+0x24/0x40
[  459.361123]  ? finish_task_switch+0x125/0x600
[  459.361812]  ? finish_task_switch+0xee/0x600
[  459.362471]  ? mark_held_locks+0xf0/0xf0
[  459.363108]  ? __schedule+0x96f/0x21d0
[  459.363716]  lock_acquire+0x111/0x320
[  459.364285]  ? blkdev_get+0xce/0xbe0
[  459.364846]  ? blkdev_get+0xce/0xbe0
[  459.365390]  __mutex_lock+0xf9/0x12a0
[  459.365948]  ? blkdev_get+0xce/0xbe0
[  459.366493]  ? bdev_evict_inode+0x1f0/0x1f0
[  459.367130]  ? blkdev_get+0xce/0xbe0
[  459.367678]  ? destroy_inode+0xbc/0x110
[  459.368261]  ? mutex_trylock+0x1a0/0x1a0
[  459.368867]  ? __blkdev_get+0x3e6/0x1280
[  459.369463]  ? bdev_disk_changed+0x1d0/0x1d0
[  459.370114]  ? blkdev_get+0xce/0xbe0
[  459.370656]  blkdev_get+0xce/0xbe0
[  459.371178]  ? find_held_lock+0x2c/0x110
[  459.371774]  ? __blkdev_get+0x1280/0x1280
[  459.372383]  ? lock_downgrade+0x680/0x680
[  459.373002]  ? lock_acquire+0x111/0x320
[  459.373587]  ? bd_acquire+0x21/0x2c0
[  459.374134]  ? do_raw_spin_unlock+0x4f/0x250
[  459.374780]  blkdev_open+0x202/0x290
[  459.375325]  do_dentry_open+0x49e/0x1050
[  459.375924]  ? blkdev_get_by_dev+0x70/0x70
[  459.376543]  ? __x64_sys_fchdir+0x1f0/0x1f0
[  459.377192]  ? inode_permission+0xbe/0x3a0
[  459.377818]  path_openat+0x148c/0x3f50
[  459.378392]  ? kmem_cache_alloc+0xd5/0x280
[  459.379016]  ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.379802]  ? path_lookupat.isra.0+0x900/0x900
[  459.380489]  ? __lock_is_held+0xad/0x140
[  459.381093]  do_filp_open+0x1a1/0x280
[  459.381654]  ? may_open_dev+0xf0/0xf0
[  459.382214]  ? find_held_lock+0x2c/0x110
[  459.382816]  ? lock_downgrade+0x680/0x680
[  459.383425]  ? __lock_is_held+0xad/0x140
[  459.384024]  ? do_raw_spin_unlock+0x4f/0x250
[  459.384668]  ? _raw_spin_unlock+0x1f/0x30
[  459.385280]  ? __alloc_fd+0x448/0x560
[  459.385841]  do_sys_open+0x3c3/0x500
[  459.386386]  ? filp_open+0x70/0x70
[  459.386911]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[  459.387610]  ? trace_hardirqs_off_caller+0x55/0x1c0
[  459.388342]  ? do_syscall_64+0x1a/0x520
[  459.388930]  do_syscall_64+0xc3/0x520
[  459.389490]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.390248] RIP: 0033:0x416211
[  459.390720] Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83
04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f
   05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d
      01
[  459.393483] RSP: 002b:00007fe45dfe9a60 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
[  459.394610] RAX: ffffffffffffffda RBX: 00007fe45dfea6d4 RCX: 0000000000416211
[  459.395678] RDX: 00007fe45dfe9b0a RSI: 0000000000000002 RDI: 00007fe45dfe9b00
[  459.396758] RBP: 000000000076bf20 R08: 0000000000000000 R09: 000000000000000a
[  459.397930] R10: 0000000000000075 R11: 0000000000000293 R12: 00000000ffffffff
[  459.399022] R13: 0000000000000bd9 R14: 00000000004cdb80 R15: 000000000076bf2c
[  459.400168]
[  459.400430] Allocated by task 20132:
[  459.401038]  kasan_kmalloc+0xbf/0xe0
[  459.401652]  kmem_cache_alloc+0xd5/0x280
[  459.402330]  bdev_alloc_inode+0x18/0x40
[  459.402970]  alloc_inode+0x5f/0x180
[  459.403510]  iget5_locked+0x57/0xd0
[  459.404095]  bdget+0x94/0x4e0
[  459.404607]  bd_acquire+0xfa/0x2c0
[  459.405113]  blkdev_open+0x110/0x290
[  459.405702]  do_dentry_open+0x49e/0x1050
[  459.406340]  path_openat+0x148c/0x3f50
[  459.406926]  do_filp_open+0x1a1/0x280
[  459.407471]  do_sys_open+0x3c3/0x500
[  459.408010]  do_syscall_64+0xc3/0x520
[  459.408572]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  459.409415]
[  459.409679] Freed by task 1262:
[  459.410212]  __kasan_slab_free+0x129/0x170
[  459.410919]  kmem_cache_free+0xb2/0x2a0
[  459.411564]  rcu_process_callbacks+0xbb2/0x2320
[  459.412318]  __do_softirq+0x225/0x8ac

Fix this by delaying bdput() to the end of blkdev_get() which means we
have finished accessing bdev.

Fixes: 77ea887 ("implement in-kernel gendisk events handling")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
commit e5a15e1 upstream.

The following kernel panic was captured when running nfs server over
ocfs2, at that time ocfs2_test_inode_bit() was checking whether one
inode locating at "blkno" 5 was valid, that is ocfs2 root inode, its
"suballoc_slot" was OCFS2_INVALID_SLOT(65535) and it was allocted from
//global_inode_alloc, but here it wrongly assumed that it was got from per
slot inode alloctor which would cause array overflow and trigger kernel
panic.

  BUG: unable to handle kernel paging request at 0000000000001088
  IP: [<ffffffff816f6898>] _raw_spin_lock+0x18/0xf0
  PGD 1e06ba067 PUD 1e9e7d067 PMD 0
  Oops: 0002 [gregkh#1] SMP
  CPU: 6 PID: 24873 Comm: nfsd Not tainted 4.1.12-124.36.1.el6uek.x86_64 gregkh#2
  Hardware name: Huawei CH121 V3/IT11SGCA1, BIOS 3.87 02/02/2018
  RIP: _raw_spin_lock+0x18/0xf0
  RSP: e02b:ffff88005ae97908  EFLAGS: 00010206
  RAX: ffff88005ae98000 RBX: 0000000000001088 RCX: 0000000000000000
  RDX: 0000000000020000 RSI: 0000000000000009 RDI: 0000000000001088
  RBP: ffff88005ae97928 R08: 0000000000000000 R09: ffff880212878e00
  R10: 0000000000007ff0 R11: 0000000000000000 R12: 0000000000001088
  R13: ffff8800063c0aa8 R14: ffff8800650c27d0 R15: 000000000000ffff
  FS:  0000000000000000(0000) GS:ffff880218180000(0000) knlGS:ffff880218180000
  CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000001088 CR3: 00000002033d0000 CR4: 0000000000042660
  Call Trace:
    igrab+0x1e/0x60
    ocfs2_get_system_file_inode+0x63/0x3a0 [ocfs2]
    ocfs2_test_inode_bit+0x328/0xa00 [ocfs2]
    ocfs2_get_parent+0xba/0x3e0 [ocfs2]
    reconnect_path+0xb5/0x300
    exportfs_decode_fh+0xf6/0x2b0
    fh_verify+0x350/0x660 [nfsd]
    nfsd4_putfh+0x4d/0x60 [nfsd]
    nfsd4_proc_compound+0x3d3/0x6f0 [nfsd]
    nfsd_dispatch+0xe0/0x290 [nfsd]
    svc_process_common+0x412/0x6a0 [sunrpc]
    svc_process+0x123/0x210 [sunrpc]
    nfsd+0xff/0x170 [nfsd]
    kthread+0xcb/0xf0
    ret_from_fork+0x61/0x90
  Code: 83 c2 02 0f b7 f2 e8 18 dc 91 ff 66 90 eb bf 0f 1f 40 00 55 48 89 e5 41 56 41 55 41 54 53 0f 1f 44 00 00 48 89 fb ba 00 00 02 00 <f0> 0f c1 17 89 d0 45 31 e4 45 31 ed c1 e8 10 66 39 d0 41 89 c6
  RIP   _raw_spin_lock+0x18/0xf0
  CR2: 0000000000001088
  ---[ end trace 7264463cd1aac8f9 ]---
  Kernel panic - not syncing: Fatal exception

Link: http://lkml.kernel.org/r/20200616183829.87211-4-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 26, 2020
[ Upstream commit 440ab9e ]

At times when I'm using kgdb I see a splat on my console about
suspicious RCU usage.  I managed to come up with a case that could
reproduce this that looked like this:

  WARNING: suspicious RCU usage
  5.7.0-rc4+ #609 Not tainted
  -----------------------------
  kernel/pid.c:395 find_task_by_pid_ns() needs rcu_read_lock() protection!

  other info that might help us debug this:

    rcu_scheduler_active = 2, debug_locks = 1
  3 locks held by swapper/0/1:
   #0: ffffff81b6b8e988 (&dev->mutex){....}-{3:3}, at: __device_attach+0x40/0x13c
   gregkh#1: ffffffd01109e9e8 (dbg_master_lock){....}-{2:2}, at: kgdb_cpu_enter+0x20c/0x7ac
   gregkh#2: ffffffd01109ea90 (dbg_slave_lock){....}-{2:2}, at: kgdb_cpu_enter+0x3ec/0x7ac

  stack backtrace:
  CPU: 7 PID: 1 Comm: swapper/0 Not tainted 5.7.0-rc4+ #609
  Hardware name: Google Cheza (rev3+) (DT)
  Call trace:
   dump_backtrace+0x0/0x1b8
   show_stack+0x1c/0x24
   dump_stack+0xd4/0x134
   lockdep_rcu_suspicious+0xf0/0x100
   find_task_by_pid_ns+0x5c/0x80
   getthread+0x8c/0xb0
   gdb_serial_stub+0x9d4/0xd04
   kgdb_cpu_enter+0x284/0x7ac
   kgdb_handle_exception+0x174/0x20c
   kgdb_brk_fn+0x24/0x30
   call_break_hook+0x6c/0x7c
   brk_handler+0x20/0x5c
   do_debug_exception+0x1c8/0x22c
   el1_sync_handler+0x3c/0xe4
   el1_sync+0x7c/0x100
   rpmh_rsc_probe+0x38/0x420
   platform_drv_probe+0x94/0xb4
   really_probe+0x134/0x300
   driver_probe_device+0x68/0x100
   __device_attach_driver+0x90/0xa8
   bus_for_each_drv+0x84/0xcc
   __device_attach+0xb4/0x13c
   device_initial_probe+0x18/0x20
   bus_probe_device+0x38/0x98
   device_add+0x38c/0x420

If I understand properly we should just be able to blanket kgdb under
one big RCU read lock and the problem should go away.  We'll add it to
the beast-of-a-function known as kgdb_cpu_enter().

With this I no longer get any splats and things seem to work fine.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200602154729.v2.1.I70e0d4fd46d5ed2aaf0c98a355e8e1b7a5bb7e4e@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Jul 29, 2020
[ Upstream commit cb551b8 ]

In BRM_status_show(), if the condition "!ioc->is_warpdrive" tested on entry
to the function is true, a "goto out" is called. This results in unlocking
ioc->pci_access_mutex without this mutex lock being taken.  This generates
the following splat:

[ 1148.539883] mpt3sas_cm2: BRM_status_show: BRM attribute is only for warpdrive
[ 1148.547184]
[ 1148.548708] =====================================
[ 1148.553501] WARNING: bad unlock balance detected!
[ 1148.558277] 5.8.0-rc3+ #827 Not tainted
[ 1148.562183] -------------------------------------
[ 1148.566959] cat/5008 is trying to release lock (&ioc->pci_access_mutex) at:
[ 1148.574035] [<ffffffffc070b7a3>] BRM_status_show+0xd3/0x100 [mpt3sas]
[ 1148.580574] but there are no more locks to release!
[ 1148.585524]
[ 1148.585524] other info that might help us debug this:
[ 1148.599624] 3 locks held by cat/5008:
[ 1148.607085]  #0: ffff92aea3e392c0 (&p->lock){+.+.}-{3:3}, at: seq_read+0x34/0x480
[ 1148.618509]  gregkh#1: ffff922ef14c4888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x2a/0xb0
[ 1148.630729]  gregkh#2: ffff92aedb5d7310 (kn->active#224){.+.+}-{0:0}, at: kernfs_seq_start+0x32/0xb0
[ 1148.643347]
[ 1148.643347] stack backtrace:
[ 1148.655259] CPU: 73 PID: 5008 Comm: cat Not tainted 5.8.0-rc3+ #827
[ 1148.665309] Hardware name: HGST H4060-S/S2600STB, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019
[ 1148.678394] Call Trace:
[ 1148.684750]  dump_stack+0x78/0xa0
[ 1148.691802]  lock_release.cold+0x45/0x4a
[ 1148.699451]  __mutex_unlock_slowpath+0x35/0x270
[ 1148.707675]  BRM_status_show+0xd3/0x100 [mpt3sas]
[ 1148.716092]  dev_attr_show+0x19/0x40
[ 1148.723664]  sysfs_kf_seq_show+0x87/0x100
[ 1148.731193]  seq_read+0xbc/0x480
[ 1148.737882]  vfs_read+0xa0/0x160
[ 1148.744514]  ksys_read+0x58/0xd0
[ 1148.751129]  do_syscall_64+0x4c/0xa0
[ 1148.757941]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1148.766240] RIP: 0033:0x7f1230566542
[ 1148.772957] Code: Bad RIP value.
[ 1148.779206] RSP: 002b:00007ffeac1bcac8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 1148.790063] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f1230566542
[ 1148.800284] RDX: 0000000000020000 RSI: 00007f1223460000 RDI: 0000000000000003
[ 1148.810474] RBP: 00007f1223460000 R08: 00007f122345f010 R09: 0000000000000000
[ 1148.820641] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000
[ 1148.830728] R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000

Fix this by returning immediately instead of jumping to the out label.

Link: https://lore.kernel.org/r/20200701085254.51740-1-damien.lemoal@wdc.com
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jul 31, 2020
[ Upstream commit cb551b8 ]

In BRM_status_show(), if the condition "!ioc->is_warpdrive" tested on entry
to the function is true, a "goto out" is called. This results in unlocking
ioc->pci_access_mutex without this mutex lock being taken.  This generates
the following splat:

[ 1148.539883] mpt3sas_cm2: BRM_status_show: BRM attribute is only for warpdrive
[ 1148.547184]
[ 1148.548708] =====================================
[ 1148.553501] WARNING: bad unlock balance detected!
[ 1148.558277] 5.8.0-rc3+ #827 Not tainted
[ 1148.562183] -------------------------------------
[ 1148.566959] cat/5008 is trying to release lock (&ioc->pci_access_mutex) at:
[ 1148.574035] [<ffffffffc070b7a3>] BRM_status_show+0xd3/0x100 [mpt3sas]
[ 1148.580574] but there are no more locks to release!
[ 1148.585524]
[ 1148.585524] other info that might help us debug this:
[ 1148.599624] 3 locks held by cat/5008:
[ 1148.607085]  #0: ffff92aea3e392c0 (&p->lock){+.+.}-{3:3}, at: seq_read+0x34/0x480
[ 1148.618509]  #1: ffff922ef14c4888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x2a/0xb0
[ 1148.630729]  #2: ffff92aedb5d7310 (kn->active#224){.+.+}-{0:0}, at: kernfs_seq_start+0x32/0xb0
[ 1148.643347]
[ 1148.643347] stack backtrace:
[ 1148.655259] CPU: 73 PID: 5008 Comm: cat Not tainted 5.8.0-rc3+ #827
[ 1148.665309] Hardware name: HGST H4060-S/S2600STB, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019
[ 1148.678394] Call Trace:
[ 1148.684750]  dump_stack+0x78/0xa0
[ 1148.691802]  lock_release.cold+0x45/0x4a
[ 1148.699451]  __mutex_unlock_slowpath+0x35/0x270
[ 1148.707675]  BRM_status_show+0xd3/0x100 [mpt3sas]
[ 1148.716092]  dev_attr_show+0x19/0x40
[ 1148.723664]  sysfs_kf_seq_show+0x87/0x100
[ 1148.731193]  seq_read+0xbc/0x480
[ 1148.737882]  vfs_read+0xa0/0x160
[ 1148.744514]  ksys_read+0x58/0xd0
[ 1148.751129]  do_syscall_64+0x4c/0xa0
[ 1148.757941]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1148.766240] RIP: 0033:0x7f1230566542
[ 1148.772957] Code: Bad RIP value.
[ 1148.779206] RSP: 002b:00007ffeac1bcac8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 1148.790063] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f1230566542
[ 1148.800284] RDX: 0000000000020000 RSI: 00007f1223460000 RDI: 0000000000000003
[ 1148.810474] RBP: 00007f1223460000 R08: 00007f122345f010 R09: 0000000000000000
[ 1148.820641] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000
[ 1148.830728] R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000

Fix this by returning immediately instead of jumping to the out label.

Link: https://lore.kernel.org/r/20200701085254.51740-1-damien.lemoal@wdc.com
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
imaami pushed a commit to imaami/linux that referenced this pull request Aug 2, 2020
Ido Schimmel says:

====================
mlxsw fixes

This patch set contains various fixes for mlxsw.

Patches gregkh#1-gregkh#2 fix two trap related issues introduced in previous cycle.

Patches gregkh#3-gregkh#5 fix rare use-after-frees discovered by syzkaller. After
over a week of fuzzing with the fixes, the bugs did not reproduce.

Patch gregkh#6 from Amit fixes an issue in the ethtool selftest that was
recently discovered after running the test on a new platform that
supports only 1Gbps and 10Gbps speeds.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
imaami pushed a commit to imaami/linux that referenced this pull request Aug 2, 2020
This patch fixes a race condition that causes a use-after-free during
amdgpu_dm_atomic_commit_tail. This can occur when 2 non-blocking commits
are requested and the second one finishes before the first. Essentially,
this bug occurs when the following sequence of events happens:

1. Non-blocking commit gregkh#1 is requested w/ a new dm_state gregkh#1 and is
deferred to the workqueue.

2. Non-blocking commit gregkh#2 is requested w/ a new dm_state gregkh#2 and is
deferred to the workqueue.

3. Commit gregkh#2 starts before commit gregkh#1, dm_state gregkh#1 is used in the
commit_tail and commit gregkh#2 completes, freeing dm_state gregkh#1.

4. Commit gregkh#1 starts after commit gregkh#2 completes, uses the freed dm_state
1 and dereferences a freelist pointer while setting the context.

Since this bug has only been spotted with fast commits, this patch fixes
the bug by clearing the dm_state instead of using the old dc_state for
fast updates. In addition, since dm_state is only used for its dc_state
and amdgpu_dm_atomic_commit_tail will retain the dc_state if none is found,
removing the dm_state should not have any consequences in fast updates.

This use-after-free bug has existed for a while now, but only caused a
noticeable issue starting from 5.7-rc1 due to 3202fa6 ("slub: relocate
freelist pointer to middle of object") moving the freelist pointer from
dm_state->base (which was unused) to dm_state->context (which is
dereferenced).

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207383
Fixes: bd200d1 ("drm/amd/display: Don't replace the dc_state for fast updates")
Reported-by: Duncan <1i5t5.duncan@cox.net>
Signed-off-by: Mazin Rezk <mnrzk@protonmail.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
imaami pushed a commit to imaami/linux that referenced this pull request Aug 2, 2020
I compiled with AddressSanitizer and I had these memory leaks while I
was using the tep_parse_format function:

    Direct leak of 28 byte(s) in 4 object(s) allocated from:
        #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe)
        gregkh#1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985
        gregkh#2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140
        gregkh#3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206
        gregkh#4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291
        gregkh#5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299
        gregkh#6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849
        gregkh#7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161
        gregkh#8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207
        gregkh#9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786
        gregkh#10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285
        gregkh#11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369
        gregkh#12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335
        gregkh#13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389
        gregkh#14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431
        gregkh#15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251
        gregkh#16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284
        gregkh#17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593
        gregkh#18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727
        gregkh#19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048
        gregkh#20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127
        gregkh#21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152
        #22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252
        #23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347
        #24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461
        #25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673
        #26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

The token variable in the process_dynamic_array_len function is
allocated in the read_expect_type function, but is not freed before
calling the read_token function.

Free the token variable before calling read_token in order to plug the
leak.

Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
steev pushed a commit to steev/linux-1 that referenced this pull request Aug 4, 2020
GFP_KERNEL flag specifies a normal kernel allocation in which executing
in process context without any locks and can sleep.
mmio_diff takes sometime to finish all the diff compare and it has
locks, continue using GFP_KERNEL will output below trace if LOCKDEP
enabled.

Use GFP_ATOMIC instead.

V2: Rebase.

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.7.0-rc2 #400 Not tainted
-----------------------------------------------------
is trying to acquire:
ffffffffb47bea20 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_acquire.part.0+0x0/0x30

               and this task is already holding:
ffff88845b85cc90 (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2}, at: vgpu_mmio_diff_show+0xcf/0x2e0
which would create a new lock dependency:
 (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2} -> (fs_reclaim){+.+.}-{0:0}

               but this new dependency connects a SOFTIRQ-irq-safe lock:
 (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2}

               ... which became SOFTIRQ-irq-safe at:
  lock_acquire+0x175/0x4e0
  _raw_spin_lock_irqsave+0x2b/0x40
  shadow_context_status_change+0xfe/0x2f0
  notifier_call_chain+0x6a/0xa0
  __atomic_notifier_call_chain+0x5f/0xf0
  execlists_schedule_out+0x42a/0x820
  process_csb+0xe7/0x3e0
  execlists_submission_tasklet+0x5c/0x1d0
  tasklet_action_common.isra.0+0xeb/0x260
  __do_softirq+0x11d/0x56f
  irq_exit+0xf6/0x100
  do_IRQ+0x7f/0x160
  ret_from_intr+0x0/0x2a
  cpuidle_enter_state+0xcd/0x5b0
  cpuidle_enter+0x37/0x60
  do_idle+0x337/0x3f0
  cpu_startup_entry+0x14/0x20
  start_kernel+0x58b/0x5c5
  secondary_startup_64+0xa4/0xb0

               to a SOFTIRQ-irq-unsafe lock:
 (fs_reclaim){+.+.}-{0:0}

               ... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x175/0x4e0
  fs_reclaim_acquire.part.0+0x20/0x30
  kmem_cache_alloc_node_trace+0x2e/0x290
  alloc_worker+0x2b/0xb0
  init_rescuer.part.0+0x17/0xe0
  workqueue_init+0x293/0x3bb
  kernel_init_freeable+0x149/0x325
  kernel_init+0x8/0x116
  ret_from_fork+0x3a/0x50

               other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(fs_reclaim);
                               local_irq_disable();
                               lock(&gvt->scheduler.mmio_context_lock);
                               lock(fs_reclaim);
  <Interrupt>
    lock(&gvt->scheduler.mmio_context_lock);

                *** DEADLOCK ***

3 locks held by cat/1439:
 #0: ffff888444a23698 (&p->lock){+.+.}-{3:3}, at: seq_read+0x49/0x680
 gregkh#1: ffff88845b858068 (&gvt->lock){+.+.}-{3:3}, at: vgpu_mmio_diff_show+0xc7/0x2e0
 gregkh#2: ffff88845b85cc90 (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2}, at: vgpu_mmio_diff_show+0xcf/0x2e0

               the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2} ops: 31 {
   HARDIRQ-ON-W at:
                    lock_acquire+0x175/0x4e0
                    _raw_spin_lock_bh+0x2f/0x40
                    vgpu_mmio_diff_show+0xcf/0x2e0
                    seq_read+0x242/0x680
                    full_proxy_read+0x95/0xc0
                    vfs_read+0xc2/0x1b0
                    ksys_read+0xc4/0x160
                    do_syscall_64+0x63/0x290
                    entry_SYSCALL_64_after_hwframe+0x49/0xb3
   IN-SOFTIRQ-W at:
                    lock_acquire+0x175/0x4e0
                    _raw_spin_lock_irqsave+0x2b/0x40
                    shadow_context_status_change+0xfe/0x2f0
                    notifier_call_chain+0x6a/0xa0
                    __atomic_notifier_call_chain+0x5f/0xf0
                    execlists_schedule_out+0x42a/0x820
                    process_csb+0xe7/0x3e0
                    execlists_submission_tasklet+0x5c/0x1d0
                    tasklet_action_common.isra.0+0xeb/0x260
                    __do_softirq+0x11d/0x56f
                    irq_exit+0xf6/0x100
                    do_IRQ+0x7f/0x160
                    ret_from_intr+0x0/0x2a
                    cpuidle_enter_state+0xcd/0x5b0
                    cpuidle_enter+0x37/0x60
                    do_idle+0x337/0x3f0
                    cpu_startup_entry+0x14/0x20
                    start_kernel+0x58b/0x5c5
                    secondary_startup_64+0xa4/0xb0
   INITIAL USE at:
                   lock_acquire+0x175/0x4e0
                   _raw_spin_lock_irqsave+0x2b/0x40
                   shadow_context_status_change+0xfe/0x2f0
                   notifier_call_chain+0x6a/0xa0
                   __atomic_notifier_call_chain+0x5f/0xf0
                   execlists_schedule_in+0x2c8/0x690
                   __execlists_submission_tasklet+0x1303/0x1930
                   execlists_submit_request+0x1e7/0x230
                   submit_notify+0x105/0x2a4
                   __i915_sw_fence_complete+0xaa/0x380
                   __engine_park+0x313/0x5a0
                   ____intel_wakeref_put_last+0x3e/0x90
                   intel_gt_resume+0x41e/0x440
                   intel_gt_init+0x283/0xbc0
                   i915_gem_init+0x197/0x240
                   i915_driver_probe+0xc2d/0x12e0
                   i915_pci_probe+0xa2/0x1e0
                   local_pci_probe+0x6f/0xb0
                   pci_device_probe+0x171/0x230
                   really_probe+0x17a/0x380
                   driver_probe_device+0x70/0xf0
                   device_driver_attach+0x82/0x90
                   __driver_attach+0x60/0x100
                   bus_for_each_dev+0xe4/0x140
                   bus_add_driver+0x257/0x2a0
                   driver_register+0xd3/0x150
                   i915_init+0x6d/0x80
                   do_one_initcall+0xb8/0x3a0
                   kernel_init_freeable+0x2b4/0x325
                   kernel_init+0x8/0x116
                   ret_from_fork+0x3a/0x50
 }
__key.77812+0x0/0x40
 ... acquired at:
   lock_acquire+0x175/0x4e0
   fs_reclaim_acquire.part.0+0x20/0x30
   kmem_cache_alloc_trace+0x2e/0x260
   mmio_diff_handler+0xc0/0x150
   intel_gvt_for_each_tracked_mmio+0x7b/0x140
   vgpu_mmio_diff_show+0x111/0x2e0
   seq_read+0x242/0x680
   full_proxy_read+0x95/0xc0
   vfs_read+0xc2/0x1b0
   ksys_read+0xc4/0x160
   do_syscall_64+0x63/0x290
   entry_SYSCALL_64_after_hwframe+0x49/0xb3

               the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
-> (fs_reclaim){+.+.}-{0:0} ops: 1999031 {
   HARDIRQ-ON-W at:
                    lock_acquire+0x175/0x4e0
                    fs_reclaim_acquire.part.0+0x20/0x30
                    kmem_cache_alloc_node_trace+0x2e/0x290
                    alloc_worker+0x2b/0xb0
                    init_rescuer.part.0+0x17/0xe0
                    workqueue_init+0x293/0x3bb
                    kernel_init_freeable+0x149/0x325
                    kernel_init+0x8/0x116
                    ret_from_fork+0x3a/0x50
   SOFTIRQ-ON-W at:
                    lock_acquire+0x175/0x4e0
                    fs_reclaim_acquire.part.0+0x20/0x30
                    kmem_cache_alloc_node_trace+0x2e/0x290
                    alloc_worker+0x2b/0xb0
                    init_rescuer.part.0+0x17/0xe0
                    workqueue_init+0x293/0x3bb
                    kernel_init_freeable+0x149/0x325
                    kernel_init+0x8/0x116
                    ret_from_fork+0x3a/0x50
   INITIAL USE at:
                   lock_acquire+0x175/0x4e0
                   fs_reclaim_acquire.part.0+0x20/0x30
                   kmem_cache_alloc_node_trace+0x2e/0x290
                   alloc_worker+0x2b/0xb0
                   init_rescuer.part.0+0x17/0xe0
                   workqueue_init+0x293/0x3bb
                   kernel_init_freeable+0x149/0x325
                   kernel_init+0x8/0x116
                   ret_from_fork+0x3a/0x50
 }
__fs_reclaim_map+0x0/0x60
 ... acquired at:
   lock_acquire+0x175/0x4e0
   fs_reclaim_acquire.part.0+0x20/0x30
   kmem_cache_alloc_trace+0x2e/0x260
   mmio_diff_handler+0xc0/0x150
   intel_gvt_for_each_tracked_mmio+0x7b/0x140
   vgpu_mmio_diff_show+0x111/0x2e0
   seq_read+0x242/0x680
   full_proxy_read+0x95/0xc0
   vfs_read+0xc2/0x1b0
   ksys_read+0xc4/0x160
   do_syscall_64+0x63/0x290
   entry_SYSCALL_64_after_hwframe+0x49/0xb3

               stack backtrace:
CPU: 5 PID: 1439 Comm: cat Not tainted 5.7.0-rc2 #400
Hardware name: Intel(R) Client Systems NUC8i7BEH/NUC8BEB, BIOS BECFL357.86A.0056.2018.1128.1717 11/28/2018
Call Trace:
 dump_stack+0x97/0xe0
 check_irq_usage.cold+0x428/0x434
 ? check_usage_forwards+0x2c0/0x2c0
 ? class_equal+0x11/0x20
 ? __bfs+0xd2/0x2d0
 ? in_any_class_list+0xa0/0xa0
 ? check_path+0x22/0x40
 ? check_noncircular+0x150/0x2b0
 ? print_circular_bug.isra.0+0x1b0/0x1b0
 ? mark_lock+0x13d/0xc50
 ? __lock_acquire+0x1e32/0x39b0
 __lock_acquire+0x1e32/0x39b0
 ? timerqueue_add+0xc1/0x130
 ? register_lock_class+0xa60/0xa60
 ? mark_lock+0x13d/0xc50
 lock_acquire+0x175/0x4e0
 ? __zone_pcp_update+0x80/0x80
 ? check_flags.part.0+0x210/0x210
 ? mark_held_locks+0x65/0x90
 ? _raw_spin_unlock_irqrestore+0x32/0x40
 ? lockdep_hardirqs_on+0x190/0x290
 ? fwtable_read32+0x163/0x480
 ? mmio_diff_handler+0xc0/0x150
 fs_reclaim_acquire.part.0+0x20/0x30
 ? __zone_pcp_update+0x80/0x80
 kmem_cache_alloc_trace+0x2e/0x260
 mmio_diff_handler+0xc0/0x150
 ? vgpu_mmio_diff_open+0x30/0x30
 intel_gvt_for_each_tracked_mmio+0x7b/0x140
 vgpu_mmio_diff_show+0x111/0x2e0
 ? mmio_diff_handler+0x150/0x150
 ? rcu_read_lock_sched_held+0xa0/0xb0
 ? rcu_read_lock_bh_held+0xc0/0xc0
 ? kasan_unpoison_shadow+0x33/0x40
 ? __kasan_kmalloc.constprop.0+0xc2/0xd0
 seq_read+0x242/0x680
 ? debugfs_locked_down.isra.0+0x70/0x70
 full_proxy_read+0x95/0xc0
 vfs_read+0xc2/0x1b0
 ksys_read+0xc4/0x160
 ? kernel_write+0xb0/0xb0
 ? mark_held_locks+0x24/0x90
 do_syscall_64+0x63/0x290
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x7ffbe3e6efb2
Code: c0 e9 c2 fe ff ff 50 48 8d 3d ca cb 0a 00 e8 f5 19 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
RSP: 002b:00007ffd021c08a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007ffbe3e6efb2
RDX: 0000000000020000 RSI: 00007ffbe34cd000 RDI: 0000000000000003
RBP: 00007ffbe34cd000 R08: 00007ffbe34cc010 R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000562b6f0a11f0
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000
------------[ cut here ]------------

Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200601035556.19999-1-colin.xu@intel.com
imaami pushed a commit to imaami/linux that referenced this pull request Aug 5, 2020
commit fde9f39 upstream.

This patch fixes a race condition that causes a use-after-free during
amdgpu_dm_atomic_commit_tail. This can occur when 2 non-blocking commits
are requested and the second one finishes before the first. Essentially,
this bug occurs when the following sequence of events happens:

1. Non-blocking commit gregkh#1 is requested w/ a new dm_state gregkh#1 and is
deferred to the workqueue.

2. Non-blocking commit gregkh#2 is requested w/ a new dm_state gregkh#2 and is
deferred to the workqueue.

3. Commit gregkh#2 starts before commit gregkh#1, dm_state gregkh#1 is used in the
commit_tail and commit gregkh#2 completes, freeing dm_state gregkh#1.

4. Commit gregkh#1 starts after commit gregkh#2 completes, uses the freed dm_state
1 and dereferences a freelist pointer while setting the context.

Since this bug has only been spotted with fast commits, this patch fixes
the bug by clearing the dm_state instead of using the old dc_state for
fast updates. In addition, since dm_state is only used for its dc_state
and amdgpu_dm_atomic_commit_tail will retain the dc_state if none is found,
removing the dm_state should not have any consequences in fast updates.

This use-after-free bug has existed for a while now, but only caused a
noticeable issue starting from 5.7-rc1 due to 3202fa6 ("slub: relocate
freelist pointer to middle of object") moving the freelist pointer from
dm_state->base (which was unused) to dm_state->context (which is
dereferenced).

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207383
Fixes: bd200d1 ("drm/amd/display: Don't replace the dc_state for fast updates")
Reported-by: Duncan <1i5t5.duncan@cox.net>
Signed-off-by: Mazin Rezk <mnrzk@protonmail.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Aug 7, 2020
commit fde9f39 upstream.

This patch fixes a race condition that causes a use-after-free during
amdgpu_dm_atomic_commit_tail. This can occur when 2 non-blocking commits
are requested and the second one finishes before the first. Essentially,
this bug occurs when the following sequence of events happens:

1. Non-blocking commit #1 is requested w/ a new dm_state #1 and is
deferred to the workqueue.

2. Non-blocking commit #2 is requested w/ a new dm_state #2 and is
deferred to the workqueue.

3. Commit #2 starts before commit #1, dm_state #1 is used in the
commit_tail and commit #2 completes, freeing dm_state #1.

4. Commit #1 starts after commit #2 completes, uses the freed dm_state
1 and dereferences a freelist pointer while setting the context.

Since this bug has only been spotted with fast commits, this patch fixes
the bug by clearing the dm_state instead of using the old dc_state for
fast updates. In addition, since dm_state is only used for its dc_state
and amdgpu_dm_atomic_commit_tail will retain the dc_state if none is found,
removing the dm_state should not have any consequences in fast updates.

This use-after-free bug has existed for a while now, but only caused a
noticeable issue starting from 5.7-rc1 due to 3202fa6 ("slub: relocate
freelist pointer to middle of object") moving the freelist pointer from
dm_state->base (which was unused) to dm_state->context (which is
dereferenced).

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207383
Fixes: bd200d1 ("drm/amd/display: Don't replace the dc_state for fast updates")
Reported-by: Duncan <1i5t5.duncan@cox.net>
Signed-off-by: Mazin Rezk <mnrzk@protonmail.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Aug 11, 2020
[ Upstream commit e24c644 ]

I compiled with AddressSanitizer and I had these memory leaks while I
was using the tep_parse_format function:

    Direct leak of 28 byte(s) in 4 object(s) allocated from:
        #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe)
        #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985
        #2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140
        #3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206
        #4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291
        #5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299
        #6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849
        #7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161
        #8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207
        #9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786
        #10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285
        #11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369
        #12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335
        #13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389
        #14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431
        #15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251
        #16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284
        #17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593
        #18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727
        #19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048
        #20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127
        #21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152
        #22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252
        #23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347
        #24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461
        #25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673
        #26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

The token variable in the process_dynamic_array_len function is
allocated in the read_expect_type function, but is not freed before
calling the read_token function.

Free the token variable before calling read_token in order to plug the
leak.

Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Aug 11, 2020
[ Upstream commit e24c644 ]

I compiled with AddressSanitizer and I had these memory leaks while I
was using the tep_parse_format function:

    Direct leak of 28 byte(s) in 4 object(s) allocated from:
        #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe)
        #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985
        #2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140
        #3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206
        #4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291
        #5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299
        #6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849
        #7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161
        #8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207
        #9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786
        #10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285
        #11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369
        #12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335
        #13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389
        #14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431
        #15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251
        #16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284
        #17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593
        #18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727
        #19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048
        #20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127
        #21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152
        #22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252
        #23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347
        #24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461
        #25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673
        #26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

The token variable in the process_dynamic_array_len function is
allocated in the read_expect_type function, but is not freed before
calling the read_token function.

Free the token variable before calling read_token in order to plug the
leak.

Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
piso77 pushed a commit to piso77/linux that referenced this pull request Sep 18, 2025
syzkaller has caught us red-handed once more, this time nesting regular
spinlocks behind raw spinlocks:

  =============================
  [ BUG: Invalid wait context ]
  6.16.0-rc3-syzkaller-g7b8346bd9fce #0 Not tainted
  -----------------------------
  syz.0.29/3743 is trying to lock:
  a3ff80008e2e9e18 (&xa->xa_lock#20){....}-{3:3}, at: vgic_put_irq+0xb4/0x190 arch/arm64/kvm/vgic/vgic.c:137
  other info that might help us debug this:
  context-{5:5}
  3 locks held by syz.0.29/3743:
   #0: a3ff80008e2e90a8 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vgic_destroy+0x50/0x624 arch/arm64/kvm/vgic/vgic-init.c:499
   gregkh#1: a3ff80008e2e9fa0 (&kvm->arch.config_lock){+.+.}-{4:4}, at: kvm_vgic_destroy+0x5c/0x624 arch/arm64/kvm/vgic/vgic-init.c:500
   gregkh#2: 58f0000021be1428 (&vgic_cpu->ap_list_lock){....}-{2:2}, at: vgic_flush_pending_lpis+0x3c/0x31c arch/arm64/kvm/vgic/vgic.c:150
  stack backtrace:
  CPU: 0 UID: 0 PID: 3743 Comm: syz.0.29 Not tainted 6.16.0-rc3-syzkaller-g7b8346bd9fce #0 PREEMPT
  Hardware name: linux,dummy-virt (DT)
  Call trace:
   show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
   __dump_stack+0x30/0x40 lib/dump_stack.c:94
   dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
   dump_stack+0x1c/0x28 lib/dump_stack.c:129
   print_lock_invalid_wait_context kernel/locking/lockdep.c:4833 [inline]
   check_wait_context kernel/locking/lockdep.c:4905 [inline]
   __lock_acquire+0x978/0x299c kernel/locking/lockdep.c:5190
   lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5871
   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
   _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162
   vgic_put_irq+0xb4/0x190 arch/arm64/kvm/vgic/vgic.c:137
   vgic_flush_pending_lpis+0x24c/0x31c arch/arm64/kvm/vgic/vgic.c:158
   __kvm_vgic_vcpu_destroy+0x44/0x500 arch/arm64/kvm/vgic/vgic-init.c:455
   kvm_vgic_destroy+0x100/0x624 arch/arm64/kvm/vgic/vgic-init.c:505
   kvm_arch_destroy_vm+0x80/0x138 arch/arm64/kvm/arm.c:244
   kvm_destroy_vm virt/kvm/kvm_main.c:1308 [inline]
   kvm_put_kvm+0x800/0xff8 virt/kvm/kvm_main.c:1344
   kvm_vm_release+0x58/0x78 virt/kvm/kvm_main.c:1367
   __fput+0x4ac/0x980 fs/file_table.c:465
   ____fput+0x20/0x58 fs/file_table.c:493
   task_work_run+0x1bc/0x254 kernel/task_work.c:227
   resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
   do_notify_resume+0x1b4/0x270 arch/arm64/kernel/entry-common.c:151
   exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]
   exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]
   el0_svc+0xb4/0x160 arch/arm64/kernel/entry-common.c:768
   el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
   el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

This is of course no good, but is at odds with how LPI refcounts are
managed. Solve the locking mess by deferring the release of unreferenced
LPIs after the ap_list_lock is released. Mark these to-be-released LPIs
specially to avoid racing with vgic_put_irq() and causing a double-free.

Since references can only be taken on LPIs with a nonzero refcount,
extending the lifetime of freed LPIs is still safe.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Reported-by: syzbot+cef594105ac7e60c6d93@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/kvmarm/68acd0d9.a00a0220.33401d.048b.GAE@google.com/
Link: https://lore.kernel.org/r/20250905100531.282980-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
piso77 pushed a commit to piso77/linux that referenced this pull request Sep 18, 2025
…ostcopy

When you run a KVM guest with vhost-net and migrate that guest to
another host, and you immediately enable postcopy after starting the
migration, there is a big chance that the network connection of the
guest won't work anymore on the destination side after the migration.

With a debug kernel v6.16.0, there is also a call trace that looks
like this:

 FAULT_FLAG_ALLOW_RETRY missing 881
 CPU: 6 UID: 0 PID: 549 Comm: kworker/6:2 Kdump: loaded Not tainted 6.16.0 #56 NONE
 Hardware name: IBM 3931 LA1 400 (LPAR)
 Workqueue: events irqfd_inject [kvm]
 Call Trace:
  [<00003173cbecc634>] dump_stack_lvl+0x104/0x168
  [<00003173cca69588>] handle_userfault+0xde8/0x1310
  [<00003173cc756f0c>] handle_pte_fault+0x4fc/0x760
  [<00003173cc759212>] __handle_mm_fault+0x452/0xa00
  [<00003173cc7599ba>] handle_mm_fault+0x1fa/0x6a0
  [<00003173cc73409a>] __get_user_pages+0x4aa/0xba0
  [<00003173cc7349e8>] get_user_pages_remote+0x258/0x770
  [<000031734be6f052>] get_map_page+0xe2/0x190 [kvm]
  [<000031734be6f910>] adapter_indicators_set+0x50/0x4a0 [kvm]
  [<000031734be7f674>] set_adapter_int+0xc4/0x170 [kvm]
  [<000031734be2f268>] kvm_set_irq+0x228/0x3f0 [kvm]
  [<000031734be27000>] irqfd_inject+0xd0/0x150 [kvm]
  [<00003173cc00c9ec>] process_one_work+0x87c/0x1490
  [<00003173cc00dda6>] worker_thread+0x7a6/0x1010
  [<00003173cc02dc36>] kthread+0x3b6/0x710
  [<00003173cbed2f0c>] __ret_from_fork+0xdc/0x7f0
  [<00003173cdd737ca>] ret_from_fork+0xa/0x30
 3 locks held by kworker/6:2/549:
  #0: 00000000800bc958 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7ee/0x1490
  gregkh#1: 000030f3d527fbd0 ((work_completion)(&irqfd->inject)){+.+.}-{0:0}, at: process_one_work+0x81c/0x1490
  gregkh#2: 00000000f99862b0 (&mm->mmap_lock){++++}-{3:3}, at: get_map_page+0xa8/0x190 [kvm]

The "FAULT_FLAG_ALLOW_RETRY missing" indicates that handle_userfaultfd()
saw a page fault request without ALLOW_RETRY flag set, hence userfaultfd
cannot remotely resolve it (because the caller was asking for an immediate
resolution, aka, FAULT_FLAG_NOWAIT, while remote faults can take time).
With that, get_map_page() failed and the irq was lost.

We should not be strictly in an atomic environment here and the worker
should be sleepable (the call is done during an ioctl from userspace),
so we can allow adapter_indicators_set() to just sleep waiting for the
remote fault instead.

Link: https://issues.redhat.com/browse/RHEL-42486
Signed-off-by: Peter Xu <peterx@redhat.com>
[thuth: Assembled patch description and fixed some cosmetical issues]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: f654706 ("KVM: s390/interrupt: do not pin adapter interrupt pages")
[frankja: Added fixes tag]
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
zhuyj pushed a commit to zhuyj/linux that referenced this pull request Sep 18, 2025
Problem description
===================

Lockdep reports a possible circular locking dependency (AB/BA) between
&pl->state_mutex and &phy->lock, as follows.

phylink_resolve() // acquires &pl->state_mutex
-> phylink_major_config()
   -> phy_config_inband() // acquires &pl->phydev->lock

whereas all the other call sites where &pl->state_mutex and
&pl->phydev->lock have the locking scheme reversed. Everywhere else,
&pl->phydev->lock is acquired at the top level, and &pl->state_mutex at
the lower level. A clear example is phylink_bringup_phy().

The outlier is the newly introduced phy_config_inband() and the existing
lock order is the correct one. To understand why it cannot be the other
way around, it is sufficient to consider phylink_phy_change(), phylink's
callback from the PHY device's phy->phy_link_change() virtual method,
invoked by the PHY state machine.

phy_link_up() and phy_link_down(), the (indirect) callers of
phylink_phy_change(), are called with &phydev->lock acquired.
Then phylink_phy_change() acquires its own &pl->state_mutex, to
serialize changes made to its pl->phy_state and pl->link_config.
So all other instances of &pl->state_mutex and &phydev->lock must be
consistent with this order.

Problem impact
==============

I think the kernel runs a serious deadlock risk if an existing
phylink_resolve() thread, which results in a phy_config_inband() call,
is concurrent with a phy_link_up() or phy_link_down() call, which will
deadlock on &pl->state_mutex in phylink_phy_change(). Practically
speaking, the impact may be limited by the slow speed of the medium
auto-negotiation protocol, which makes it unlikely for the current state
to still be unresolved when a new one is detected, but I think the
problem is there. Nonetheless, the problem was discovered using lockdep.

Proposed solution
=================

Practically speaking, the phy_config_inband() requirement of having
phydev->lock acquired must transfer to the caller (phylink is the only
caller). There, it must bubble up until immediately before
&pl->state_mutex is acquired, for the cases where that takes place.

Solution details, considerations, notes
=======================================

This is the phy_config_inband() call graph:

                          sfp_upstream_ops :: connect_phy()
                          |
                          v
                          phylink_sfp_connect_phy()
                          |
                          v
                          phylink_sfp_config_phy()
                          |
                          |   sfp_upstream_ops :: module_insert()
                          |   |
                          |   v
                          |   phylink_sfp_module_insert()
                          |   |
                          |   |   sfp_upstream_ops :: module_start()
                          |   |   |
                          |   |   v
                          |   |   phylink_sfp_module_start()
                          |   |   |
                          |   v   v
                          |   phylink_sfp_config_optical()
 phylink_start()          |   |
   |   phylink_resume()   v   v
   |   |  phylink_sfp_set_config()
   |   |  |
   v   v  v
 phylink_mac_initial_config()
   |   phylink_resolve()
   |   |  phylink_ethtool_ksettings_set()
   v   v  v
   phylink_major_config()
            |
            v
    phy_config_inband()

phylink_major_config() caller gregkh#1, phylink_mac_initial_config(), does not
acquire &pl->state_mutex nor do its callers. It must acquire
&pl->phydev->lock prior to calling phylink_major_config().

phylink_major_config() caller gregkh#2, phylink_resolve() acquires
&pl->state_mutex, thus also needs to acquire &pl->phydev->lock.

phylink_major_config() caller gregkh#3, phylink_ethtool_ksettings_set(), is
completely uninteresting, because it only calls phylink_major_config()
if pl->phydev is NULL (otherwise it calls phy_ethtool_ksettings_set()).
We need to change nothing there.

Other solutions
===============

The lock inversion between &pl->state_mutex and &pl->phydev->lock has
occurred at least once before, as seen in commit c718af2 ("net:
phylink: fix ethtool -A with attached PHYs"). The solution there was to
simply not call phy_set_asym_pause() under the &pl->state_mutex. That
cannot be extended to our case though, where the phy_config_inband()
call is much deeper inside the &pl->state_mutex section.

Fixes: 5fd0f1a ("net: phylink: add negotiation of in-band capabilities")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250904125238.193990-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
zhuyj pushed a commit to zhuyj/linux that referenced this pull request Sep 18, 2025
5da3d94 ("PCI: mvebu: Use for_each_of_range() iterator for parsing
"ranges"") simplified code by using the for_each_of_range() iterator, but
it broke PCI enumeration on Turris Omnia (and probably other mvebu
targets).

Issue gregkh#1:

To determine range.flags, of_pci_range_parser_one() uses bus->get_flags(),
which resolves to of_bus_pci_get_flags(), which already returns an
IORESOURCE bit field, and NOT the original flags from the "ranges"
resource.

Then mvebu_get_tgt_attr() attempts the very same conversion again.  Remove
the misinterpretation of range.flags in mvebu_get_tgt_attr(), to restore
the intended behavior.

Issue gregkh#2:

The driver needs target and attributes, which are encoded in the raw
address values of the "/soc/pcie/ranges" resource. According to
of_pci_range_parser_one(), the raw values are stored in range.bus_addr and
range.parent_bus_addr, respectively. range.cpu_addr is a translated version
of range.parent_bus_addr, and not relevant here.

Use the correct range structure member, to extract target and attributes.
This restores the intended behavior.

Fixes: 5da3d94 ("PCI: mvebu: Use for_each_of_range() iterator for parsing "ranges"")
Reported-by: Jan Palus <jpalus@fastmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220479
Signed-off-by: Klaus Kudielka <klaus.kudielka@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Tony Dinh <mibodhi@gmail.com>
Tested-by: Jan Palus <jpalus@fastmail.com>
Link: https://patch.msgid.link/20250907102303.29735-1-klaus.kudielka@gmail.com
gregkh pushed a commit that referenced this pull request Sep 19, 2025
[ Upstream commit e2a10da ]

Problem description
===================

Lockdep reports a possible circular locking dependency (AB/BA) between
&pl->state_mutex and &phy->lock, as follows.

phylink_resolve() // acquires &pl->state_mutex
-> phylink_major_config()
   -> phy_config_inband() // acquires &pl->phydev->lock

whereas all the other call sites where &pl->state_mutex and
&pl->phydev->lock have the locking scheme reversed. Everywhere else,
&pl->phydev->lock is acquired at the top level, and &pl->state_mutex at
the lower level. A clear example is phylink_bringup_phy().

The outlier is the newly introduced phy_config_inband() and the existing
lock order is the correct one. To understand why it cannot be the other
way around, it is sufficient to consider phylink_phy_change(), phylink's
callback from the PHY device's phy->phy_link_change() virtual method,
invoked by the PHY state machine.

phy_link_up() and phy_link_down(), the (indirect) callers of
phylink_phy_change(), are called with &phydev->lock acquired.
Then phylink_phy_change() acquires its own &pl->state_mutex, to
serialize changes made to its pl->phy_state and pl->link_config.
So all other instances of &pl->state_mutex and &phydev->lock must be
consistent with this order.

Problem impact
==============

I think the kernel runs a serious deadlock risk if an existing
phylink_resolve() thread, which results in a phy_config_inband() call,
is concurrent with a phy_link_up() or phy_link_down() call, which will
deadlock on &pl->state_mutex in phylink_phy_change(). Practically
speaking, the impact may be limited by the slow speed of the medium
auto-negotiation protocol, which makes it unlikely for the current state
to still be unresolved when a new one is detected, but I think the
problem is there. Nonetheless, the problem was discovered using lockdep.

Proposed solution
=================

Practically speaking, the phy_config_inband() requirement of having
phydev->lock acquired must transfer to the caller (phylink is the only
caller). There, it must bubble up until immediately before
&pl->state_mutex is acquired, for the cases where that takes place.

Solution details, considerations, notes
=======================================

This is the phy_config_inband() call graph:

                          sfp_upstream_ops :: connect_phy()
                          |
                          v
                          phylink_sfp_connect_phy()
                          |
                          v
                          phylink_sfp_config_phy()
                          |
                          |   sfp_upstream_ops :: module_insert()
                          |   |
                          |   v
                          |   phylink_sfp_module_insert()
                          |   |
                          |   |   sfp_upstream_ops :: module_start()
                          |   |   |
                          |   |   v
                          |   |   phylink_sfp_module_start()
                          |   |   |
                          |   v   v
                          |   phylink_sfp_config_optical()
 phylink_start()          |   |
   |   phylink_resume()   v   v
   |   |  phylink_sfp_set_config()
   |   |  |
   v   v  v
 phylink_mac_initial_config()
   |   phylink_resolve()
   |   |  phylink_ethtool_ksettings_set()
   v   v  v
   phylink_major_config()
            |
            v
    phy_config_inband()

phylink_major_config() caller #1, phylink_mac_initial_config(), does not
acquire &pl->state_mutex nor do its callers. It must acquire
&pl->phydev->lock prior to calling phylink_major_config().

phylink_major_config() caller #2, phylink_resolve() acquires
&pl->state_mutex, thus also needs to acquire &pl->phydev->lock.

phylink_major_config() caller #3, phylink_ethtool_ksettings_set(), is
completely uninteresting, because it only calls phylink_major_config()
if pl->phydev is NULL (otherwise it calls phy_ethtool_ksettings_set()).
We need to change nothing there.

Other solutions
===============

The lock inversion between &pl->state_mutex and &pl->phydev->lock has
occurred at least once before, as seen in commit c718af2 ("net:
phylink: fix ethtool -A with attached PHYs"). The solution there was to
simply not call phy_set_asym_pause() under the &pl->state_mutex. That
cannot be extended to our case though, where the phy_config_inband()
call is much deeper inside the &pl->state_mutex section.

Fixes: 5fd0f1a ("net: phylink: add negotiation of in-band capabilities")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250904125238.193990-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Sep 19, 2025
[ Upstream commit b816265 ]

5da3d94 ("PCI: mvebu: Use for_each_of_range() iterator for parsing
"ranges"") simplified code by using the for_each_of_range() iterator, but
it broke PCI enumeration on Turris Omnia (and probably other mvebu
targets).

Issue #1:

To determine range.flags, of_pci_range_parser_one() uses bus->get_flags(),
which resolves to of_bus_pci_get_flags(), which already returns an
IORESOURCE bit field, and NOT the original flags from the "ranges"
resource.

Then mvebu_get_tgt_attr() attempts the very same conversion again.  Remove
the misinterpretation of range.flags in mvebu_get_tgt_attr(), to restore
the intended behavior.

Issue #2:

The driver needs target and attributes, which are encoded in the raw
address values of the "/soc/pcie/ranges" resource. According to
of_pci_range_parser_one(), the raw values are stored in range.bus_addr and
range.parent_bus_addr, respectively. range.cpu_addr is a translated version
of range.parent_bus_addr, and not relevant here.

Use the correct range structure member, to extract target and attributes.
This restores the intended behavior.

Fixes: 5da3d94 ("PCI: mvebu: Use for_each_of_range() iterator for parsing "ranges"")
Reported-by: Jan Palus <jpalus@fastmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220479
Signed-off-by: Klaus Kudielka <klaus.kudielka@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Tony Dinh <mibodhi@gmail.com>
Tested-by: Jan Palus <jpalus@fastmail.com>
Link: https://patch.msgid.link/20250907102303.29735-1-klaus.kudielka@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
github-actions bot pushed a commit to sirdarckcat/linux-1 that referenced this pull request Sep 25, 2025
This attemps to fix possible UAFs caused by struct mgmt_pending being
freed while still being processed like in the following trace, in order
to fix mgmt_pending_valid is introduce and use to check if the
mgmt_pending hasn't been removed from the pending list, on the complete
callbacks it is used to check and in addtion remove the cmd from the list
while holding mgmt_pending_lock to avoid TOCTOU problems since if the cmd
is left on the list it can still be accessed and freed.

BUG: KASAN: slab-use-after-free in mgmt_add_adv_patterns_monitor_sync+0x35/0x50 net/bluetooth/mgmt.c:5223
Read of size 8 at addr ffff8880709d4dc0 by task kworker/u11:0/55

CPU: 0 UID: 0 PID: 55 Comm: kworker/u11:0 Not tainted 6.16.4 gregkh#2 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 mgmt_add_adv_patterns_monitor_sync+0x35/0x50 net/bluetooth/mgmt.c:5223
 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16.4/arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 12210:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4364
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 mgmt_pending_new+0x65/0x1e0 net/bluetooth/mgmt_util.c:269
 mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296
 __add_adv_patterns_monitor+0x130/0x200 net/bluetooth/mgmt.c:5247
 add_adv_patterns_monitor+0x214/0x360 net/bluetooth/mgmt.c:5364
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 sock_write_iter+0x258/0x330 net/socket.c:1133
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 12221:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4648 [inline]
 kfree+0x18e/0x440 mm/slub.c:4847
 mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline]
 mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257
 __mgmt_power_off+0x169/0x350 net/bluetooth/mgmt.c:9444
 hci_dev_close_sync+0x754/0x1330 net/bluetooth/hci_sync.c:5290
 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline]
 hci_dev_close+0x108/0x200 net/bluetooth/hci_core.c:526
 sock_do_ioctl+0xd9/0x300 net/socket.c:1192
 sock_ioctl+0x576/0x790 net/socket.c:1313
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: cf75ad8 ("Bluetooth: hci_sync: Convert MGMT_SET_POWERED")
Fixes: 2bd1b23 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_DISCOVERABLE to use cmd_sync")
Fixes: f056a65 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_CONNECTABLE to use cmd_sync")
Fixes: 3244845 ("Bluetooth: hci_sync: Convert MGMT_OP_SSP")
Fixes: d81a494 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_LE")
Fixes: b338d91 ("Bluetooth: Implement support for Mesh")
Fixes: 6f6ff38 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_LOCAL_NAME")
Fixes: 71efbb0 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_PHY_CONFIGURATION")
Fixes: b747a83 ("Bluetooth: hci_sync: Refactor add Adv Monitor")
Fixes: abfeea4 ("Bluetooth: hci_sync: Convert MGMT_OP_START_DISCOVERY")
Fixes: 26ac4c5 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_ADVERTISING")
Reported-by: cen zhang <zzzccc427@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
github-actions bot pushed a commit to sirdarckcat/linux-1 that referenced this pull request Sep 25, 2025
Ido Schimmel says:

====================
nexthop: Various fixes

Patch gregkh#1 fixes a NPD that was recently reported by syzbot.

Patch gregkh#2 fixes an issue in the existing FIB nexthop selftest.

Patch gregkh#3 extends the selftest with test cases for the bug that was fixed
in the first patch.
====================

Link: https://patch.msgid.link/20250921150824.149157-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 1, 2025
Leon Hwang says:

====================
bpf: Allow union argument in trampoline based programs

While tracing 'release_pages' with bpfsnoop[0], the verifier reports:

The function release_pages arg0 type UNION is unsupported.

However, it should be acceptable to trace functions that have 'union'
arguments.

This patch set enables such support in the verifier by allowing 'union'
as a valid argument type.

Changes:
v3 -> v4:
* Address comments from Alexei:
  * Trim bpftrace output in patch gregkh#1 log.
  * Drop the referenced commit info and the test output in patch gregkh#2 log.

v2 -> v3:
* Address comments from Alexei:
  * Reuse the existing flag BTF_FMODEL_STRUCT_ARG.
  * Update the comment of the flag BTF_FMODEL_STRUCT_ARG.

v1 -> v2:
* Add 16B 'union' argument support in x86_64 trampoline.
* Update selftests using bpf_testmod.
* Add test case about 16-bytes 'union' argument.
* Address comments from Alexei:
  * Study the patch set about 'struct' argument support.
  * Update selftests to cover more cases.
v1: https://lore.kernel.org/bpf/20250905133226.84675-1-leon.hwang@linux.dev/

Links:
[0] https://github.com/bpfsnoop/bpfsnoop
====================

Link: https://patch.msgid.link/20250919044110.23729-1-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
gregkh pushed a commit that referenced this pull request Oct 2, 2025
[ Upstream commit 1a251f5 ]

This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics.  The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.

These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:

 - trivial duplicated macro definitions have been removed

   Note that 'trivial' here means that it's obviously kernel code that
   already included all the major kernel headers, and thus gets the new
   generic MIN/MAX macros automatically.

 - non-trivial duplicated macro definitions are guarded with #ifndef

   This is the "yes, they define their own versions, but no, the include
   situation is not entirely obvious, and maybe they don't get the
   generic version automatically" case.

 - strange use case #1

   A couple of drivers decided that the way they want to describe their
   versioning is with

	#define MAJ 1
	#define MIN 2
	#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)

   which adds zero value and I just did my Alexander the Great
   impersonation, and rewrote that pointless Gordian knot as

	#define DRV_VERSION "1.2"

   instead.

 - strange use case #2

   A couple of drivers thought that it's a good idea to have a random
   'MIN' or 'MAX' define for a value or index into a table, rather than
   the traditional macro that takes arguments.

   These values were re-written as C enum's instead. The new
   function-line macros only expand when followed by an open
   parenthesis, and thus don't clash with enum use.

Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.

Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eliav Farber <farbere@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Oct 2, 2025
[ Upstream commit 65c7cde ]

The discussion about removing the side effect of irq_set_affinity_hint() of
actually applying the cpumask (if not NULL) as affinity to the interrupt,
unearthed a few unpleasantries:

  1) The modular perf drivers rely on the current behaviour for the very
     wrong reasons.

  2) While none of the other drivers prevents user space from changing
     the affinity, a cursorily inspection shows that there are at least
     expectations in some drivers.

#1 needs to be cleaned up anyway, so that's not a problem

#2 might result in subtle regressions especially when irqbalanced (which
   nowadays ignores the affinity hint) is disabled.

Provide new interfaces:

  irq_update_affinity_hint()  - Only sets the affinity hint pointer
  irq_set_affinity_and_hint() - Set the pointer and apply the affinity to
                                the interrupt

Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and
document it to be phased out.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com
Link: https://lore.kernel.org/r/20210903152430.244937-2-nitesh@redhat.com
Stable-dep-of: 915470e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path")
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Oct 2, 2025
[ Upstream commit 302a1f6 ]

This attemps to fix possible UAFs caused by struct mgmt_pending being
freed while still being processed like in the following trace, in order
to fix mgmt_pending_valid is introduce and use to check if the
mgmt_pending hasn't been removed from the pending list, on the complete
callbacks it is used to check and in addtion remove the cmd from the list
while holding mgmt_pending_lock to avoid TOCTOU problems since if the cmd
is left on the list it can still be accessed and freed.

BUG: KASAN: slab-use-after-free in mgmt_add_adv_patterns_monitor_sync+0x35/0x50 net/bluetooth/mgmt.c:5223
Read of size 8 at addr ffff8880709d4dc0 by task kworker/u11:0/55

CPU: 0 UID: 0 PID: 55 Comm: kworker/u11:0 Not tainted 6.16.4 #2 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 mgmt_add_adv_patterns_monitor_sync+0x35/0x50 net/bluetooth/mgmt.c:5223
 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16.4/arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 12210:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4364
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 mgmt_pending_new+0x65/0x1e0 net/bluetooth/mgmt_util.c:269
 mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296
 __add_adv_patterns_monitor+0x130/0x200 net/bluetooth/mgmt.c:5247
 add_adv_patterns_monitor+0x214/0x360 net/bluetooth/mgmt.c:5364
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 sock_write_iter+0x258/0x330 net/socket.c:1133
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 12221:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4648 [inline]
 kfree+0x18e/0x440 mm/slub.c:4847
 mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline]
 mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257
 __mgmt_power_off+0x169/0x350 net/bluetooth/mgmt.c:9444
 hci_dev_close_sync+0x754/0x1330 net/bluetooth/hci_sync.c:5290
 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline]
 hci_dev_close+0x108/0x200 net/bluetooth/hci_core.c:526
 sock_do_ioctl+0xd9/0x300 net/socket.c:1192
 sock_ioctl+0x576/0x790 net/socket.c:1313
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: cf75ad8 ("Bluetooth: hci_sync: Convert MGMT_SET_POWERED")
Fixes: 2bd1b23 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_DISCOVERABLE to use cmd_sync")
Fixes: f056a65 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_CONNECTABLE to use cmd_sync")
Fixes: 3244845 ("Bluetooth: hci_sync: Convert MGMT_OP_SSP")
Fixes: d81a494 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_LE")
Fixes: b338d91 ("Bluetooth: Implement support for Mesh")
Fixes: 6f6ff38 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_LOCAL_NAME")
Fixes: 71efbb0 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_PHY_CONFIGURATION")
Fixes: b747a83 ("Bluetooth: hci_sync: Refactor add Adv Monitor")
Fixes: abfeea4 ("Bluetooth: hci_sync: Convert MGMT_OP_START_DISCOVERY")
Fixes: 26ac4c5 ("Bluetooth: hci_sync: Convert MGMT_OP_SET_ADVERTISING")
Reported-by: cen zhang <zzzccc427@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Oct 2, 2025
[ Upstream commit 1a251f5 ]

This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics.  The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.

These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:

 - trivial duplicated macro definitions have been removed

   Note that 'trivial' here means that it's obviously kernel code that
   already included all the major kernel headers, and thus gets the new
   generic MIN/MAX macros automatically.

 - non-trivial duplicated macro definitions are guarded with #ifndef

   This is the "yes, they define their own versions, but no, the include
   situation is not entirely obvious, and maybe they don't get the
   generic version automatically" case.

 - strange use case #1

   A couple of drivers decided that the way they want to describe their
   versioning is with

	#define MAJ 1
	#define MIN 2
	#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)

   which adds zero value and I just did my Alexander the Great
   impersonation, and rewrote that pointless Gordian knot as

	#define DRV_VERSION "1.2"

   instead.

 - strange use case #2

   A couple of drivers thought that it's a good idea to have a random
   'MIN' or 'MAX' define for a value or index into a table, rather than
   the traditional macro that takes arguments.

   These values were re-written as C enum's instead. The new
   function-line macros only expand when followed by an open
   parenthesis, and thus don't clash with enum use.

Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.

Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eliav Farber <farbere@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Oct 2, 2025
[ Upstream commit 65c7cde ]

The discussion about removing the side effect of irq_set_affinity_hint() of
actually applying the cpumask (if not NULL) as affinity to the interrupt,
unearthed a few unpleasantries:

  1) The modular perf drivers rely on the current behaviour for the very
     wrong reasons.

  2) While none of the other drivers prevents user space from changing
     the affinity, a cursorily inspection shows that there are at least
     expectations in some drivers.

#1 needs to be cleaned up anyway, so that's not a problem

#2 might result in subtle regressions especially when irqbalanced (which
   nowadays ignores the affinity hint) is disabled.

Provide new interfaces:

  irq_update_affinity_hint()  - Only sets the affinity hint pointer
  irq_set_affinity_and_hint() - Set the pointer and apply the affinity to
                                the interrupt

Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and
document it to be phased out.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com
Link: https://lore.kernel.org/r/20210903152430.244937-2-nitesh@redhat.com
Stable-dep-of: 915470e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path")
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Oct 2, 2025
[ Upstream commit 65c7cde ]

The discussion about removing the side effect of irq_set_affinity_hint() of
actually applying the cpumask (if not NULL) as affinity to the interrupt,
unearthed a few unpleasantries:

  1) The modular perf drivers rely on the current behaviour for the very
     wrong reasons.

  2) While none of the other drivers prevents user space from changing
     the affinity, a cursorily inspection shows that there are at least
     expectations in some drivers.

#1 needs to be cleaned up anyway, so that's not a problem

#2 might result in subtle regressions especially when irqbalanced (which
   nowadays ignores the affinity hint) is disabled.

Provide new interfaces:

  irq_update_affinity_hint()  - Only sets the affinity hint pointer
  irq_set_affinity_and_hint() - Set the pointer and apply the affinity to
                                the interrupt

Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and
document it to be phased out.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com
Link: https://lore.kernel.org/r/20210903152430.244937-2-nitesh@redhat.com
Stable-dep-of: 915470e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path")
Signed-off-by: Sasha Levin <sashal@kernel.org>
github-actions bot pushed a commit to sirdarckcat/linux-1 that referenced this pull request Oct 2, 2025
Following deadlock can be triggered easily by lockdep:

WARNING: possible circular locking dependency detected
6.17.0-rc3-00124-ga12c2658ced0 #1665 Not tainted
------------------------------------------------------
check/1334 is trying to acquire lock:
ff1100011d9d0678 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_unregister_queue+0x53/0x180

but task is already holding lock:
ff1100011d9d00e0 (&q->q_usage_counter(queue)gregkh#3){++++}-{0:0}, at: del_gendisk+0xba/0x110

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> gregkh#2 (&q->q_usage_counter(queue)gregkh#3){++++}-{0:0}:
       blk_queue_enter+0x40b/0x470
       blkg_conf_prep+0x7b/0x3c0
       tg_set_limit+0x10a/0x3e0
       cgroup_file_write+0xc6/0x420
       kernfs_fop_write_iter+0x189/0x280
       vfs_write+0x256/0x490
       ksys_write+0x83/0x190
       __x64_sys_write+0x21/0x30
       x64_sys_call+0x4608/0x4630
       do_syscall_64+0xdb/0x6b0
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

-> gregkh#1 (&q->rq_qos_mutex){+.+.}-{4:4}:
       __mutex_lock+0xd8/0xf50
       mutex_lock_nested+0x2b/0x40
       wbt_init+0x17e/0x280
       wbt_enable_default+0xe9/0x140
       blk_register_queue+0x1da/0x2e0
       __add_disk+0x38c/0x5d0
       add_disk_fwnode+0x89/0x250
       device_add_disk+0x18/0x30
       virtblk_probe+0x13a3/0x1800
       virtio_dev_probe+0x389/0x610
       really_probe+0x136/0x620
       __driver_probe_device+0xb3/0x230
       driver_probe_device+0x2f/0xe0
       __driver_attach+0x158/0x250
       bus_for_each_dev+0xa9/0x130
       driver_attach+0x26/0x40
       bus_add_driver+0x178/0x3d0
       driver_register+0x7d/0x1c0
       __register_virtio_driver+0x2c/0x60
       virtio_blk_init+0x6f/0xe0
       do_one_initcall+0x94/0x540
       kernel_init_freeable+0x56a/0x7b0
       kernel_init+0x2b/0x270
       ret_from_fork+0x268/0x4c0
       ret_from_fork_asm+0x1a/0x30

-> #0 (&q->sysfs_lock){+.+.}-{4:4}:
       __lock_acquire+0x1835/0x2940
       lock_acquire+0xf9/0x450
       __mutex_lock+0xd8/0xf50
       mutex_lock_nested+0x2b/0x40
       blk_unregister_queue+0x53/0x180
       __del_gendisk+0x226/0x690
       del_gendisk+0xba/0x110
       sd_remove+0x49/0xb0 [sd_mod]
       device_remove+0x87/0xb0
       device_release_driver_internal+0x11e/0x230
       device_release_driver+0x1a/0x30
       bus_remove_device+0x14d/0x220
       device_del+0x1e1/0x5a0
       __scsi_remove_device+0x1ff/0x2f0
       scsi_remove_device+0x37/0x60
       sdev_store_delete+0x77/0x100
       dev_attr_store+0x1f/0x40
       sysfs_kf_write+0x65/0x90
       kernfs_fop_write_iter+0x189/0x280
       vfs_write+0x256/0x490
       ksys_write+0x83/0x190
       __x64_sys_write+0x21/0x30
       x64_sys_call+0x4608/0x4630
       do_syscall_64+0xdb/0x6b0
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

other info that might help us debug this:

Chain exists of:
  &q->sysfs_lock --> &q->rq_qos_mutex --> &q->q_usage_counter(queue)gregkh#3

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&q->q_usage_counter(queue)gregkh#3);
                               lock(&q->rq_qos_mutex);
                               lock(&q->q_usage_counter(queue)gregkh#3);
  lock(&q->sysfs_lock);

Root cause is that queue_usage_counter is grabbed with rq_qos_mutex
held in blkg_conf_prep(), while queue should be freezed before
rq_qos_mutex from other context.

The blk_queue_enter() from blkg_conf_prep() is used to protect against
policy deactivation, which is already protected with blkcg_mutex, hence
convert blk_queue_enter() to blkcg_mutex to fix this problem. Meanwhile,
consider that blkcg_mutex is held after queue is freezed from policy
deactivation, also convert blkg_alloc() to use GFP_NOIO.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
…ively-down'

Ido Schimmel says:

====================
bridge: Redirect to backup port when port is administratively down

Patch gregkh#1 amends the bridge to redirect to the backup port when the
primary port is administratively down and not only when it does not have
a carrier. See the commit message for more details.

Patch gregkh#2 extends the bridge backup port selftest to cover this case.
====================

Link: https://patch.msgid.link/20250812080213.325298-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
This patch fixes an issue where two different flows on the same RXq
produce the same hash resulting in continuous flow overwrites.

Flow gregkh#1: A packet for Flow gregkh#1 comes in, kernel calls the steering
         function. The driver gives back a filter id. The kernel saves
	 this filter id in the selected slot. Later, the driver's
	 service task checks if any filters have expired and then
	 installs the rule for Flow gregkh#1.
Flow gregkh#2: A packet for Flow gregkh#2 comes in. It goes through the same steps.
         But this time, the chosen slot is being used by Flow gregkh#1. The
	 driver gives a new filter id and the kernel saves it in the
	 same slot. When the driver's service task runs, it runs through
	 all the flows, checks if Flow gregkh#1 should be expired, the kernel
	 returns True as the slot has a different filter id, and then
	 the driver installs the rule for Flow gregkh#2.
Flow gregkh#1: Another packet for Flow gregkh#1 comes in. The same thing repeats.
         The slot is overwritten with a new filter id for Flow gregkh#1.

This causes a repeated cycle of flow programming for missed packets,
wasting CPU cycles while not improving performance. This problem happens
at higher rates when the RPS table is small, but tests show it still
happens even with 12,000 connections and an RPS size of 16K per queue
(global table size = 144x16K = 64K).

This patch prevents overwriting an rps_dev_flow entry if it is active.
The intention is that it is better to do aRFS for the first flow instead
of hurting all flows on the same hash. Without this, two (or more) flows
on one RX queue with the same hash can keep overwriting each other. This
causes the driver to reprogram the flow repeatedly.

Changes:
  1. Add a new 'hash' field to struct rps_dev_flow.
  2. Add rps_flow_is_active(): a helper function to check if a flow is
     active or not, extracted from rps_may_expire_flow(). It is further
     simplified as per reviewer feedback.
  3. In set_rps_cpu():
     - Avoid overwriting by programming a new filter if:
        - The slot is not in use, or
        - The slot is in use but the flow is not active, or
        - The slot has an active flow with the same hash, but target CPU
          differs.
     - Save the hash in the rps_dev_flow entry.
  4. rps_may_expire_flow(): Use earlier extracted rps_flow_is_active().

Testing & results:
  - Driver: ice (E810 NIC), Kernel: net-next
  - #CPUs = #RXq = 144 (1:1)
  - Number of flows: 12K
  - Eight RPS settings from 256 to 32768. Though RPS=256 is not ideal,
    it is still sufficient to cover 12K flows (256*144 rx-queues = 64K
    global table slots)
  - Global Table Size = 144 * RPS (effectively equal to 256 * RPS)
  - Each RPS test duration = 8 mins (org code) + 8 mins (new code).
  - Metrics captured on client

Legend for following tables:
Steer-C: #times ndo_rx_flow_steer() was Called by set_rps_cpu()
Steer-L: #times ice_arfs_flow_steer() Looped over aRFS entries
Add:     #times driver actually programmed aRFS (ice_arfs_build_entry())
Del:     #times driver deleted the flow (ice_arfs_del_flow_rules())
Units:   K = 1,000 times, M = 1 million times

  |-------|---------|------|     Org Code    |---------|---------|
  | RPS   | Latency | CPU  | Add    |  Del   | Steer-C | Steer-L |
  |-------|---------|------|--------|--------|---------|---------|
  | 256   | 227.0   | 93.2 | 1.6M   | 1.6M   | 121.7M  | 267.6M  |
  | 512   | 225.9   | 94.1 | 11.5M  | 11.2M  | 65.7M   | 199.6M  |
  | 1024  | 223.5   | 95.6 | 16.5M  | 16.5M  | 27.1M   | 187.3M  |
  | 2048  | 222.2   | 96.3 | 10.5M  | 10.5M  | 12.5M   | 115.2M  |
  | 4096  | 223.9   | 94.1 | 5.5M   | 5.5M   | 7.2M    | 65.9M   |
  | 8192  | 224.7   | 92.5 | 2.7M   | 2.7M   | 3.0M    | 29.9M   |
  | 16384 | 223.5   | 92.5 | 1.3M   | 1.3M   | 1.4M    | 13.9M   |
  | 32768 | 219.6   | 93.2 | 838.1K | 838.1K | 965.1K  | 8.9M    |
  |-------|---------|------|   New Code      |---------|---------|
  | 256   | 201.5   | 99.1 | 13.4K  | 5.0K   | 13.7K   | 75.2K   |
  | 512   | 202.5   | 98.2 | 11.2K  | 5.9K   | 11.2K   | 55.5K   |
  | 1024  | 207.3   | 93.9 | 11.5K  | 9.7K   | 11.5K   | 59.6K   |
  | 2048  | 207.5   | 96.7 | 11.8K  | 11.1K  | 15.5K   | 79.3K   |
  | 4096  | 206.9   | 96.6 | 11.8K  | 11.7K  | 11.8K   | 63.2K   |
  | 8192  | 205.8   | 96.7 | 11.9K  | 11.8K  | 11.9K   | 63.9K   |
  | 16384 | 200.9   | 98.2 | 11.9K  | 11.9K  | 11.9K   | 64.2K   |
  | 32768 | 202.5   | 98.0 | 11.9K  | 11.9K  | 11.9K   | 64.2K   |
  |-------|---------|------|--------|--------|---------|---------|

Some observations:
  1. Overall Latency improved: (1790.19-1634.94)/1790.19*100 = 8.67%
  2. Overall CPU increased:    (777.32-751.49)/751.45*100    = 3.44%
  3. Flow Management (add/delete) remained almost constant at ~11K
     compared to values in millions.

Signed-off-by: Krishna Kumar <krikku@gmail.com>
Link: https://patch.msgid.link/20250825031005.3674864-2-krikku@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
Ido Schimmel says:

====================
ipv4: icmp: Fix source IP derivation in presence of VRFs

Align IPv4 with IPv6 and in the presence of VRFs generate ICMP error
messages with a source IP that is derived from the receiving interface
and not from its VRF master. This is especially important when the error
messages are "Time Exceeded" messages as it means that utilities like
traceroute will show an incorrect packet path.

Patches gregkh#1-gregkh#2 are preparations.

Patch gregkh#3 is the actual change.

Patches gregkh#4-gregkh#7 make small improvements in the existing traceroute test.

Patch gregkh#8 extends the traceroute test with VRF test cases for both IPv4
and IPv6.

Changes since v1 [1]:
* Rebase.

[1] https://lore.kernel.org/netdev/20250901083027.183468-1-idosch@nvidia.com/
====================

Link: https://patch.msgid.link/20250908073238.119240-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
Petr Machata says:

====================
bridge: Allow keeping local FDB entries only on VLAN 0

The bridge FDB contains one local entry per port per VLAN, for the MAC of
the port in question, and likewise for the bridge itself. This allows
bridge to locally receive and punt "up" any packets whose destination MAC
address matches that of one of the bridge interfaces or of the bridge
itself.

The number of these local "service" FDB entries grows linearly with number
of bridge-global VLAN memberships, but that in turn will tend to grow
quadratically with number of ports and per-port VLAN memberships. While
that does not cause issues during forwarding lookups, it does make dumps
impractically slow.

As an example, with 100 interfaces, each on 4K VLANs, a full dump of FDB
that just contains these 400K local entries, takes 6.5s. That's _without_
considering iproute2 formatting overhead, this is just how long it takes to
walk the FDB (repeatedly), serialize it into netlink messages, and parse
the messages back in userspace.

This is to illustrate that with growing number of ports and VLANs, the time
required to dump this repetitive information blows up. Arguably 4K VLANs
per interface is not a very realistic configuration, but then modern
switches can instead have several hundred interfaces, and we have fielded
requests for >1K VLAN memberships per port among customers.

FDB entries are currently all kept on a single linked list, and then
dumping uses this linked list to walk all entries and dump them in order.
When the message buffer is full, the iteration is cut short, and later
restarted. Of course, to restart the iteration, it's first necessary to
walk the already-dumped front part of the list before starting dumping
again. So one possibility is to organize the FDB entries in different
structure more amenable to walk restarts.

One option is to walk directly the hash table. The advantage is that no
auxiliary structure needs to be introduced. With a rough sketch of this
approach, the above scenario gets dumped in not quite 3 s, saving over 50 %
of time. However hash table iteration requires maintaining an active cursor
that must be collected when the dump is aborted. It looks like that would
require changes in the NDO protocol to allow to run this cleanup. Moreover,
on hash table resize the iteration is simply restarted. FDB dumps are
currently not guaranteed to correspond to any one particular state: entries
can be missed, or be duplicated. But with hash table iteration we would get
that plus the much less graceful resize behavior, where swaths of FDB are
duplicated.

Another option is to maintain the FDB entries in a red-black tree. We have
a PoC of this approach on hand, and the above scenario is dumped in about
2.5 s. Still not as snappy as we'd like it, but better than the hash table.
However the savings come at the expense of a more expensive insertion, and
require locking during dumps, which blocks insertion.

The upside of these approaches is that they provide benefits whatever the
FDB contents. But it does not seem like either of these is workable.
However we intend to clean up the RB tree PoC and present it for
consideration later on in case the trade-offs are considered acceptable.

Yet another option might be to use in-kernel FDB filtering, and to filter
the local entries when dumping. Unfortunately, this does not help all that
much either, because the linked-list walk still needs to happen. Also, with
the obvious filtering interface built around ndm_flags / ndm_state
filtering, one can't just exclude pure local entries in one query. One
needs to dump all non-local entries first, and then to get permanent
entries in another run filter local & added_by_user. I.e. one needs to pay
the iteration overhead twice, and then integrate the result in userspace.
To get significant savings, one would need a very specific knob like "dump,
but skip/only include local entries". But if we are adding a local-specific
knobs, maybe let's have an option to just not duplicate them in the first
place.

All this FDB duplication is there merely to make things snappy during
forwarding. But high-radix switches with thousands of VLANs typically do
not process much traffic in the SW datapath at all, but rather offload vast
majority of it. So we could exchange some of the runtime performance for a
neater FDB.

To that end, in this patchset, introduce a new bridge option,
BR_BOOLOPT_FDB_LOCAL_VLAN_0, which when enabled, has local FDB entries
installed only on VLAN 0, instead of duplicating them across all VLANs.
Then to maintain the local termination behavior, on FDB miss, the bridge
does a second lookup on VLAN 0.

Enabling this option changes the bridge behavior in expected ways. Since
the entries are only kept on VLAN 0, FDB get, flush and dump will not
perceive them on non-0 VLANs. And deleting the VLAN 0 entry affects
forwarding on all VLANs.

This patchset is loosely based on a privately circulated patch by Nikolay
Aleksandrov.

The patchset progresses as follows:

- Patch gregkh#1 introduces a bridge option to enable the above feature. Then
  patches gregkh#2 to gregkh#5 gradually patch the bridge to do the right thing when
  the option is enabled. Finally patch gregkh#6 adds the UAPI knob and the code
  for when the feature is enabled or disabled.
- Patches gregkh#7, gregkh#8 and gregkh#9 contain fixes and improvements to selftest
  libraries
- Patch gregkh#10 contains a new selftest
====================

Link: https://patch.msgid.link/cover.1757004393.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
Lockdep gives a splat [1] when ser_hdl_work item is executed.  It is
scheduled at mac80211 workqueue via ieee80211_queue_work() and takes a
wiphy lock inside.  However, this workqueue can be flushed when e.g.
closing the interface and wiphy lock is already taken in that case.

Choosing wiphy_work_queue() for SER is likely not suitable.  Back on to
the global workqueue.

[1]:

 WARNING: possible circular locking dependency detected
 6.17.0-rc2 gregkh#17 Not tainted
 ------------------------------------------------------
 kworker/u32:1/61 is trying to acquire lock:
 ffff88811bc00768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ser_state_run+0x5e/0x180 [rtw89_core]

 but task is already holding lock:
 ffffc9000048fd30 ((work_completion)(&ser->ser_hdl_work)){+.+.}-{0:0}, at: process_one_work+0x7b5/0x1450

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> gregkh#2 ((work_completion)(&ser->ser_hdl_work)){+.+.}-{0:0}:
        process_one_work+0x7c6/0x1450
        worker_thread+0x49e/0xd00
        kthread+0x313/0x640
        ret_from_fork+0x221/0x300
        ret_from_fork_asm+0x1a/0x30

 -> gregkh#1 ((wq_completion)phy0){+.+.}-{0:0}:
        touch_wq_lockdep_map+0x8e/0x180
        __flush_workqueue+0x129/0x10d0
        ieee80211_stop_device+0xa8/0x110
        ieee80211_do_stop+0x14ce/0x2880
        ieee80211_stop+0x13a/0x2c0
        __dev_close_many+0x18f/0x510
        __dev_change_flags+0x25f/0x670
        netif_change_flags+0x7b/0x160
        do_setlink.isra.0+0x1640/0x35d0
        rtnl_newlink+0xd8c/0x1d30
        rtnetlink_rcv_msg+0x700/0xb80
        netlink_rcv_skb+0x11d/0x350
        netlink_unicast+0x49a/0x7a0
        netlink_sendmsg+0x759/0xc20
        ____sys_sendmsg+0x812/0xa00
        ___sys_sendmsg+0xf7/0x180
        __sys_sendmsg+0x11f/0x1b0
        do_syscall_64+0xbb/0x360
        entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -> #0 (&rdev->wiphy.mtx){+.+.}-{4:4}:
        __lock_acquire+0x124c/0x1d20
        lock_acquire+0x154/0x2e0
        __mutex_lock+0x17b/0x12f0
        ser_state_run+0x5e/0x180 [rtw89_core]
        rtw89_ser_hdl_work+0x119/0x220 [rtw89_core]
        process_one_work+0x82d/0x1450
        worker_thread+0x49e/0xd00
        kthread+0x313/0x640
        ret_from_fork+0x221/0x300
        ret_from_fork_asm+0x1a/0x30

 other info that might help us debug this:

 Chain exists of:
   &rdev->wiphy.mtx --> (wq_completion)phy0 --> (work_completion)(&ser->ser_hdl_work)

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock((work_completion)(&ser->ser_hdl_work));
                                lock((wq_completion)phy0);
                                lock((work_completion)(&ser->ser_hdl_work));
   lock(&rdev->wiphy.mtx);

  *** DEADLOCK ***

 2 locks held by kworker/u32:1/61:
  #0: ffff888103835148 ((wq_completion)phy0){+.+.}-{0:0}, at: process_one_work+0xefa/0x1450
  gregkh#1: ffffc9000048fd30 ((work_completion)(&ser->ser_hdl_work)){+.+.}-{0:0}, at: process_one_work+0x7b5/0x1450

 stack backtrace:
 CPU: 0 UID: 0 PID: 61 Comm: kworker/u32:1 Not tainted 6.17.0-rc2 gregkh#17 PREEMPT(voluntary)
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS edk2-20250523-14.fc42 05/23/2025
 Workqueue: phy0 rtw89_ser_hdl_work [rtw89_core]
 Call Trace:
  <TASK>
  dump_stack_lvl+0x5d/0x80
  print_circular_bug.cold+0x178/0x1be
  check_noncircular+0x14c/0x170
  __lock_acquire+0x124c/0x1d20
  lock_acquire+0x154/0x2e0
  __mutex_lock+0x17b/0x12f0
  ser_state_run+0x5e/0x180 [rtw89_core]
  rtw89_ser_hdl_work+0x119/0x220 [rtw89_core]
  process_one_work+0x82d/0x1450
  worker_thread+0x49e/0xd00
  kthread+0x313/0x640
  ret_from_fork+0x221/0x300
  ret_from_fork_asm+0x1a/0x30
  </TASK>

Found by Linux Verification Center (linuxtesting.org).

Fixes: ebfc919 ("wifi: rtw89: add wiphy_lock() to work that isn't held wiphy_lock() yet")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250919210852.823912-5-pchelkin@ispras.ru
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
Biju <biju.das.au@gmail.com> says:

From: Biju Das <biju.das.jz@bp.renesas.com>

The calculation formula for nominal bit rate of classical CAN is same as
that of nominal bit rate of CANFD on the RZ/G3E SoC and R-Car Gen4
compared to other SoCs. Update the nominal bit rate constants.

Apart from this, for replacing function-like macros, introduced
rcar_canfd_compute_{nominal,data}_bit_rate_cfg().

v2->v3:
 * Replaced "shared_bittiming"->"shared_can_regs" as it is same for RZ/G3E
   and R-Car Gen4.
 * Updated commit header and description for patch#1.
 * Added Rb tag from Geert for patch gregkh#2,gregkh#3 and gregkh#4.
 * Dropped _MASK suffix from RCANFD_CFG_* macros.
 * Dropped _MASK suffix from RCANFD_NCFG_NBRP_MASK macro.
 * Dropped _MASK suffix from the macro RCANFD_DCFG_DBRP_MASK.
 * Followed the order as used in struct can_bittiming{_const} for easy
   maintenance.
v1->v2:
 * Dropped patch#2 as it is accepted.
 * Moved patch#4 to patch#2.
 * Updated commit header and description for patch#2.
 * Kept RCANFD_CFG* macro definitions to give a meaning to the magic
   number using GENMASK macro and used FIELD_PREP to extract value.
 * Split patch#3 for computing nominal  and data bit rate config separate.
 * Updated rcar_canfd_compute_nominal_bit_rate_cfg() to handle
   nominal bit rate configuration for both classical CAN and CANFD.
 * Replaced RCANFD_NCFG_NBRP->RCANFD_NCFG_NBRP_MASK and used FIELD_PREP to
   extract value.
 * Replaced RCANFD_DCFG_DBRP->RCANFD_DCFG_DBRP_MASK and used FIELD_PREP to
   extract value.

Link: https://patch.msgid.link/20250908120940.147196-1-biju.das.jz@bp.renesas.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
…and struct raw_sock"

Vincent Mailhol <mailhol@kernel.org> says:

A few bytes can be shaved out of can raw's struct uniqframe and struct
raw_sock.

Patch gregkh#1 reorders struct uniqframe fields to save 8 bytes.

Patch gregkh#2 and gregkh#3 modify struct raw_sock to use bitfields and to reorder
its fields to save 24 bytes in total.

Link: https://patch.msgid.link/20250917-can-raw-repack-v2-0-395e8b3a4437@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
…CAN XL step 3/3"

Vincent Mailhol <mailhol@kernel.org> says:

In November last year, I sent an RFC to introduce CAN XL [1]. That
RFC, despite positive feedback, was put on hold due to some unanswered
question concerning the PWM encoding [2].

While stuck, some small preparation work was done in parallel in [3]
by refactoring the struct can_priv and doing some trivial clean-up and
renaming. Initially, [3] received zero feedback but was eventually
merged after splitting it in smaller parts and resending it.

Finally, in July this year, we clarified the remaining mysteries about
PWM calculation, thus unlocking the series. Summer being a bit busy
because of some personal matters brings us to now.

After doing all the refactoring and adding all the CAN XL features,
the final result is more than 30 patches, definitively too much for a
single series. So I am splitting the remaining changes three:

  - can: rework the CAN MTU logic [4]
  - can: netlink: preparation before introduction of CAN XL (this series)
  - CAN XL (will come right after the two preparation series get merged)

And thus, this series continues and finishes the preparation work done
in [3] and [4]. It contains all the refactoring needed to smoothly
introduce CAN XL. The goal is to:

  - split the functions in smaller pieces: CAN XL will introduce a
    fair amount of code. And some functions which are already fairly
    long (86 lines for can_validate(), 215 lines for can_changelink())
    would grow to disproportionate sizes if the CAN XL logic were to
    be inlined in those functions.

  - repurpose the existing code to handle both CAN FD and CAN XL: a
    huge part of CAN XL simply reuses the CAN FD logic. All the
    existing CAN FD logic is made more generic to handle both CAN FD
    and XL.

In more details:

  - Patch gregkh#1 moves struct data_bittiming_params from dev.h to
    bittiming.h and patch gregkh#2 makes can_get_relative_tdco() FD agnostic
    before also moving it to bittiming.h.

  - Patch gregkh#3 adds some comments to netlink.h tagging which IFLA
    symbols are FD specific.

  - Patches gregkh#4 to gregkh#6 are refactoring can_validate() and
    can_validate_bittiming().

  - Patches gregkh#7 to gregkh#11 are refactoring can_changelink() and
    can_tdc_changelink().

  - Patches gregkh#12 and gregkh#13 are refactoring can_get_size() and
    can_tdc_get_size().

  - Patches gregkh#14 to gregkh#17 are refactoring can_fill_info() and
    can_tdc_fill_info().

  - Patch gregkh#18 makes can_calc_tdco() FD agnostic.

  - Patch gregkh#19 adds can_get_ctrlmode_str() which converts control mode
    flags into strings. This is done in preparation of patch gregkh#20.

  - Patch gregkh#20 is the final patch and improves the user experience by
    providing detailed error messages whenever invalid parameters are
    provided. All those error messages came into handy when debugging
    the upcoming CAN XL patches.

Aside from the last patch, the other changes do not impact any of the
existing functionalities.

The follow up series which introduces CAN XL is nearly completed but
will be sent only once this one is approved: one thing at a time, I do
not want to overwhelm people (including myself).

[1] https://lore.kernel.org/linux-can/20241110155902.72807-16-mailhol.vincent@wanadoo.fr/
[2] https://lore.kernel.org/linux-can/c4771c16-c578-4a6d-baee-918fe276dbe9@wanadoo.fr/
[3] https://lore.kernel.org/linux-can/20241110155902.72807-16-mailhol.vincent@wanadoo.fr/
[4] https://lore.kernel.org/linux-can/20250923-can-fix-mtu-v2-0-984f9868db69@kernel.org/

Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-0-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
Write combining is an optimization feature in CPUs that is frequently
used by modern devices to generate 32 or 64 byte TLPs at the PCIe level.
These large TLPs allow certain optimizations in the driver to HW
communication that improve performance. As WC is unpredictable and
optional the HW designs all tolerate cases where combining doesn't
happen and simply experience a performance degradation.

Unfortunately many virtualization environments on all architectures have
done things that completely disable WC inside the VM with no generic way
to detect this. For example WC was fully blocked in ARM64 KVM until
commit 8c47ce3 ("KVM: arm64: Set io memory s2 pte as normalnc for
vfio pci device").

Trying to use WC when it is known not to work has a measurable
performance cost (~5%). Long ago mlx5 developed an boot time algorithm
to test if WC is available or not by using unique mlx5 HW features to
measure how many large TLPs the device is receiving. The SW generates a
large number of combining opportunities and if any succeed then WC is
declared working.

In mlx5 the WC optimization feature is never used by the kernel except
for the boot time test. The WC is only used by userspace in rdma-core.

Sadly modern ARM CPUs, especially NVIDIA Grace, have a combining
implementation that is very unreliable compared to pretty much
everything prior. This is being fixed architecturally in new CPUs with a
new ST64B instruction, but current shipping devices suffer this problem.

Unreliable means the SW can present thousands of combining opportunities
and the HW will not combine for any of them, which creates a performance
degradation, and critically fails the mlx5 boot test. However, the CPU
is very sensitive to the instruction sequence used, with the better
options being sufficiently good that the performance loss from the
unreliable CPU is not measurable.

Broadly there are several options, from worst to best:
1) A C loop doing a u64 memcpy.
   This was used prior to commit ef30228
   ("IB/mlx5: Use __iowrite64_copy() for write combining stores")
   and failed almost all the time on Grace CPUs.

2) ARM64 assembly with consecutive 8 byte stores. This was implemented
   as an arch-generic __iowriteXX_copy() family of functions suitable
   for performance use in drivers for WC. commit ead7911
   ("arm64/io: Provide a WC friendly __iowriteXX_copy()") provided the
   ARM implementation.

3) ARM64 assembly with consecutive 16 byte stores. This was rejected
   from kernel use over fears of virtualization failures. Common ARM
   VMMs will crash if STP is used against emulated memory.

4) A single NEON store instruction. Userspace has used this option for a
   very long time, it performs well.

5) For future silicon the new ST64B instruction is guaranteed to
   generate a 64 byte TLP 100% of the time

The past upgrade from gregkh#1 to gregkh#2 was thought to be sufficient to solve
this problem. However, more testing on more systems shows that gregkh#3 is
still problematic at a low frequency and the kernel test fails.

Thus, make the mlx5 use the same instructions as userspace during the
boot time WC self test. This way the WC test matches the userspace and
will properly detect the ability of HW to support the WC workload that
userspace will generate. While gregkh#4 still has imperfect combining
performance, it is substantially better than gregkh#2, and does actually give
a performance win to applications. Self-test failures with gregkh#2 are like
3/10 boots, on some systems, gregkh#4 has never seen a boot failure.

There is no real general use case for a NEON based WC flow in the
kernel. This is not suitable for any performance path work as getting
into/out of a NEON context is fairly expensive compared to the gain of
WC. Future CPUs are going to fix this issue by using an new ARM
instruction and __iowriteXX_copy() will be updated to use that
automatically, probably using the ALTERNATES mechanism.

Since this problem is constrained to mlx5's unique situation of needing
a non-performance code path to duplicate what mlx5 userspace is doing as
a matter of self-testing, implement it as a one line inline assembly in
the driver directly.

Lastly, this was concluded from the discussion with ARM maintainers
which confirms that this is the best approach for the solution:
https://lore.kernel.org/r/aHqN_hpJl84T1Usi@arm.com

Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/1759093688-841357-1-git-send-email-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 3, 2025
…lockup

Since we use 16-bit precision, the raw data will undergo integer division,
which may sometimes result in data loss.  This can lead to slightly
inaccurate CPU utilization calculations.  Under normal circumstances, this
isn't an issue.  However, when CPU utilization reaches 100%, the
calculated result might exceed 100%.  For example, with raw data like the
following:

sample_period 400000134 new_stat 83648414036 old_stat 83247417494

sample_period=400000134/2^24=23
new_stat=83648414036/2^24=4985
old_stat=83247417494/2^24=4961
util=105%

Below log will output:

CPU#3 Utilization every 0s during lockup:
    gregkh#1:   0% system,          0% softirq,   105% hardirq,     0% idle
    gregkh#2:   0% system,          0% softirq,   105% hardirq,     0% idle
    gregkh#3:   0% system,          0% softirq,   100% hardirq,     0% idle
    gregkh#4:   0% system,          0% softirq,   105% hardirq,     0% idle
    gregkh#5:   0% system,          0% softirq,   105% hardirq,     0% idle

To avoid confusion, we enforce a 100% display cap when calculations exceed
this threshold.

We also round to the nearest multiple of 16.8 milliseconds to improve the
accuracy.

[yaozhenguo1@gmail.com: make get_16bit_precision() more accurate, fix comment layout]
  Link: https://lkml.kernel.org/r/20250818081438.40540-1-yaozhenguo@jd.com
Link: https://lkml.kernel.org/r/20250812082510.32291-1-yaozhenguo@jd.com
Signed-off-by: ZhenguoYao <yaozhenguo1@gmail.com>
Cc: Bitao Hu <yaoma@linux.alibaba.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Max Kellermann <max.kellermann@ionos.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
github-actions bot pushed a commit to sirdarckcat/linux-1 that referenced this pull request Oct 3, 2025
generic/091 may fail, then it bisects to the bad commit ba8dac3
("f2fs: fix to zero post-eof page").

What will cause generic/091 to fail is something like below Testcase gregkh#1:
1. write 16k as compressed blocks
2. truncate to 12k
3. truncate to 20k
4. verify data in range of [12k, 16k], however data is not zero as
expected

Script of Testcase gregkh#1
mkfs.f2fs -f -O extra_attr,compression /dev/vdb
mount -t f2fs -o compress_extension=* /dev/vdb /mnt/f2fs
dd if=/dev/zero of=/mnt/f2fs/file bs=12k count=1
dd if=/dev/random of=/mnt/f2fs/file bs=4k count=1 seek=3 conv=notrunc
sync
truncate -s $((12*1024)) /mnt/f2fs/file
truncate -s $((20*1024)) /mnt/f2fs/file
dd if=/mnt/f2fs/file of=/mnt/f2fs/data bs=4k count=1 skip=3
od /mnt/f2fs/data
umount /mnt/f2fs

Analisys:
in step 2), we will redirty all data pages from #0 to gregkh#3 in compressed
cluster, and zero page gregkh#3,
in step 3), f2fs_setattr() will call f2fs_zero_post_eof_page() to drop
all page cache post eof, includeing dirtied page gregkh#3,
in step 4) when we read data from page gregkh#3, it will decompressed cluster
and extra random data to page gregkh#3, finally, we hit the non-zeroed data
post eof.

However, the commit ba8dac3 ("f2fs: fix to zero post-eof page") just
let the issue be reproduced easily, w/o the commit, it can reproduce this
bug w/ below Testcase gregkh#2:
1. write 16k as compressed blocks
2. truncate to 8k
3. truncate to 12k
4. truncate to 20k
5. verify data in range of [12k, 16k], however data is not zero as
expected

Script of Testcase gregkh#2
mkfs.f2fs -f -O extra_attr,compression /dev/vdb
mount -t f2fs -o compress_extension=* /dev/vdb /mnt/f2fs
dd if=/dev/zero of=/mnt/f2fs/file bs=12k count=1
dd if=/dev/random of=/mnt/f2fs/file bs=4k count=1 seek=3 conv=notrunc
sync
truncate -s $((8*1024)) /mnt/f2fs/file
truncate -s $((12*1024)) /mnt/f2fs/file
truncate -s $((20*1024)) /mnt/f2fs/file
echo 3 > /proc/sys/vm/drop_caches
dd if=/mnt/f2fs/file of=/mnt/f2fs/data bs=4k count=1 skip=3
od /mnt/f2fs/data
umount /mnt/f2fs

Anlysis:
in step 2), we will redirty all data pages from #0 to gregkh#3 in compressed
cluster, and zero page gregkh#2 and gregkh#3,
in step 3), we will truncate page gregkh#3 in page cache,
in step 4), expand file size,
in step 5), hit random data post eof w/ the same reason in Testcase gregkh#1.

Root Cause:
In f2fs_truncate_partial_cluster(), after we truncate partial data block
on compressed cluster, all pages in cluster including the one post eof
will be dirtied, after another tuncation, dirty page post eof will be
dropped, however on-disk compressed cluster is still valid, it may
include non-zero data post eof, result in exposing previous non-zero data
post eof while reading.

Fix:
In f2fs_truncate_partial_cluster(), let change as below to fix:
- call filemap_write_and_wait_range() to flush dirty page
- call truncate_pagecache() to drop pages or zero partial page post eof
- call f2fs_do_truncate_blocks() to truncate non-compress cluster to
  last valid block

Fixes: 3265d3d ("f2fs: support partial truncation on compressed inode")
Reported-by: Jan Prusakowski <jprusakowski@google.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
github-actions bot pushed a commit to sirdarckcat/linux-1 that referenced this pull request Oct 3, 2025
As JY reported in bugzilla [1],

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
pc : [0xffffffe51d249484] f2fs_is_cp_guaranteed+0x70/0x98
lr : [0xffffffe51d24adbc] f2fs_merge_page_bio+0x520/0x6d4
CPU: 3 UID: 0 PID: 6790 Comm: kworker/u16:3 Tainted: P    B   W  OE      6.12.30-android16-5-maybe-dirty-4k gregkh#1 5f7701c9cbf727d1eebe77c89bbbeb3371e895e5
Tainted: [P]=PROPRIETARY_MODULE, [B]=BAD_PAGE, [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Workqueue: writeback wb_workfn (flush-254:49)
Call trace:
 f2fs_is_cp_guaranteed+0x70/0x98
 f2fs_inplace_write_data+0x174/0x2f4
 f2fs_do_write_data_page+0x214/0x81c
 f2fs_write_single_data_page+0x28c/0x764
 f2fs_write_data_pages+0x78c/0xce4
 do_writepages+0xe8/0x2fc
 __writeback_single_inode+0x4c/0x4b4
 writeback_sb_inodes+0x314/0x540
 __writeback_inodes_wb+0xa4/0xf4
 wb_writeback+0x160/0x448
 wb_workfn+0x2f0/0x5dc
 process_scheduled_works+0x1c8/0x458
 worker_thread+0x334/0x3f0
 kthread+0x118/0x1ac
 ret_from_fork+0x10/0x20

[1] https://bugzilla.kernel.org/show_bug.cgi?id=220575

The panic was caused by UAF issue w/ below race condition:

kworker
- writepages
 - f2fs_write_cache_pages
  - f2fs_write_single_data_page
   - f2fs_do_write_data_page
    - f2fs_inplace_write_data
     - f2fs_merge_page_bio
      - add_inu_page
      : cache page gregkh#1 into bio & cache bio in
        io->bio_list
  - f2fs_write_single_data_page
   - f2fs_do_write_data_page
    - f2fs_inplace_write_data
     - f2fs_merge_page_bio
      - add_inu_page
      : cache page gregkh#2 into bio which is linked
        in io->bio_list
						write
						- f2fs_write_begin
						: write page gregkh#1
						 - f2fs_folio_wait_writeback
						  - f2fs_submit_merged_ipu_write
						   - f2fs_submit_write_bio
						   : submit bio which inclues page gregkh#1 and gregkh#2

						software IRQ
						- f2fs_write_end_io
						 - fscrypt_free_bounce_page
						 : freed bounced page which belongs to page gregkh#2
      - inc_page_count( , WB_DATA_TYPE(data_folio), false)
      : data_folio points to fio->encrypted_page
        the bounced page can be freed before
        accessing it in f2fs_is_cp_guarantee()

It can reproduce w/ below testcase:
Run below script in shell gregkh#1:
for ((i=1;i>0;i++)) do xfs_io -f /mnt/f2fs/enc/file \
-c "pwrite 0 32k" -c "fdatasync"

Run below script in shell gregkh#2:
for ((i=1;i>0;i++)) do xfs_io -f /mnt/f2fs/enc/file \
-c "pwrite 0 32k" -c "fdatasync"

So, in f2fs_merge_page_bio(), let's avoid using fio->encrypted_page after
commit page into internal ipu cache.

Fixes: 0b20fce ("f2fs: cache global IPU bio")
Reported-by: JY <JY.Ho@mediatek.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
piso77 pushed a commit to piso77/linux that referenced this pull request Oct 4, 2025
When running as an SNP or TDX guest under KVM, force the legacy PCI hole,
i.e. memory between Top of Lower Usable DRAM and 4GiB, to be mapped as UC
via a forced variable MTRR range.

In most KVM-based setups, legacy devices such as the HPET and TPM are
enumerated via ACPI.  ACPI enumeration includes a Memory32Fixed entry, and
optionally a SystemMemory descriptor for an OperationRegion, e.g. if the
device needs to be accessed via a Control Method.

If a SystemMemory entry is present, then the kernel's ACPI driver will
auto-ioremap the region so that it can be accessed at will.  However, the
ACPI spec doesn't provide a way to enumerate the memory type of
SystemMemory regions, i.e. there's no way to tell software that a region
must be mapped as UC vs. WB, etc.  As a result, Linux's ACPI driver always
maps SystemMemory regions using ioremap_cache(), i.e. as WB on x86.

The dedicated device drivers however, e.g. the HPET driver and TPM driver,
want to map their associated memory as UC or WC, as accessing PCI devices
using WB is unsupported.

On bare metal and non-CoCO, the conflicting requirements "work" as firmware
configures the PCI hole (and other device memory) to be UC in the MTRRs.
So even though the ACPI mappings request WB, they are forced to UC- in the
kernel's tracking due to the kernel properly handling the MTRR overrides,
and thus are compatible with the drivers' requested WC/UC-.

With force WB MTRRs on SNP and TDX guests, the ACPI mappings get their
requested WB if the ACPI mappings are established before the dedicated
driver code attempts to initialize the device.  E.g. if acpi_init()
runs before the corresponding device driver is probed, ACPI's WB mapping
will "win", and result in the driver's ioremap() failing because the
existing WB mapping isn't compatible with the requested WC/UC-.

E.g. when a TPM is emulated by the hypervisor (ignoring the security
implications of relying on what is allegedly an untrusted entity to store
measurements), the TPM driver will request UC and fail:

  [  1.730459] ioremap error for 0xfed40000-0xfed45000, requested 0x2, got 0x0
  [  1.732780] tpm_tis MSFT0101:00: probe with driver tpm_tis failed with error -12

Note, the '0x2' and '0x0' values refer to "enum page_cache_mode", not x86's
memtypes (which frustratingly are an almost pure inversion; 2 == WB, 0 == UC).
E.g. tracing mapping requests for TPM TIS yields:

 Mapping TPM TIS with req_type = 0
 WARNING: CPU: 22 PID: 1 at arch/x86/mm/pat/memtype.c:530 memtype_reserve+0x2ab/0x460
 Modules linked in:
 CPU: 22 UID: 0 PID: 1 Comm: swapper/0 Tainted: G        W           6.16.0-rc7+ gregkh#2 VOLUNTARY
 Tainted: [W]=WARN
 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/29/2025
 RIP: 0010:memtype_reserve+0x2ab/0x460
  __ioremap_caller+0x16d/0x3d0
  ioremap_cache+0x17/0x30
  x86_acpi_os_ioremap+0xe/0x20
  acpi_os_map_iomem+0x1f3/0x240
  acpi_os_map_memory+0xe/0x20
  acpi_ex_system_memory_space_handler+0x273/0x440
  acpi_ev_address_space_dispatch+0x176/0x4c0
  acpi_ex_access_region+0x2ad/0x530
  acpi_ex_field_datum_io+0xa2/0x4f0
  acpi_ex_extract_from_field+0x296/0x3e0
  acpi_ex_read_data_from_field+0xd1/0x460
  acpi_ex_resolve_node_to_value+0x2ee/0x530
  acpi_ex_resolve_to_value+0x1f2/0x540
  acpi_ds_evaluate_name_path+0x11b/0x190
  acpi_ds_exec_end_op+0x456/0x960
  acpi_ps_parse_loop+0x27a/0xa50
  acpi_ps_parse_aml+0x226/0x600
  acpi_ps_execute_method+0x172/0x3e0
  acpi_ns_evaluate+0x175/0x5f0
  acpi_evaluate_object+0x213/0x490
  acpi_evaluate_integer+0x6d/0x140
  acpi_bus_get_status+0x93/0x150
  acpi_add_single_object+0x43a/0x7c0
  acpi_bus_check_add+0x149/0x3a0
  acpi_bus_check_add_1+0x16/0x30
  acpi_ns_walk_namespace+0x22c/0x360
  acpi_walk_namespace+0x15c/0x170
  acpi_bus_scan+0x1dd/0x200
  acpi_scan_init+0xe5/0x2b0
  acpi_init+0x264/0x5b0
  do_one_initcall+0x5a/0x310
  kernel_init_freeable+0x34f/0x4f0
  kernel_init+0x1b/0x200
  ret_from_fork+0x186/0x1b0
  ret_from_fork_asm+0x1a/0x30
  </TASK>

The above traces are from a Google-VMM based VM, but the same behavior
happens with a QEMU based VM that is modified to add a SystemMemory range
for the TPM TIS address space.

The only reason this doesn't cause problems for HPET, which appears to
require a SystemMemory region, is because HPET gets special treatment via
x86_init.timers.timer_init(), and so gets a chance to create its UC-
mapping before acpi_init() clobbers things.  Disabling the early call to
hpet_time_init() yields the same behavior for HPET:

  [  0.318264] ioremap error for 0xfed00000-0xfed01000, requested 0x2, got 0x0

Hack around the ACPI gap by forcing the legacy PCI hole to UC when
overriding the (virtual) MTRRs for CoCo guest, so that ioremap handling
of MTRRs naturally kicks in and forces the ACPI mappings to be UC.

Note, the requested/mapped memtype doesn't actually matter in terms of
accessing the device.  In practically every setup, legacy PCI devices are
emulated by the hypervisor, and accesses are intercepted and handled as
emulated MMIO, i.e. never access physical memory and thus don't have an
effective memtype.

Even in a theoretical setup where such devices are passed through by the
host, i.e. point at real MMIO memory, it is KVM's (as the hypervisor)
responsibility to force the memory to be WC/UC, e.g. via EPT memtype
under TDX or real hardware MTRRs under SNP.  Not doing so cannot work,
and the hypervisor is highly motivated to do the right thing as letting
the guest access hardware MMIO with WB would likely result in a variety
of fatal #MCs.

In other words, forcing the range to be UC is all about coercing the
kernel's tracking into thinking that it has established UC mappings, so
that the ioremap code doesn't reject mappings from e.g. the TPM driver and
thus prevent the driver from loading and the device from functioning.

Note gregkh#2, relying on guest firmware to handle this scenario, e.g. by setting
virtual MTRRs and then consuming them in Linux, is not a viable option, as
the virtual MTRR state is managed by the untrusted hypervisor, and because
OVMF at least has stopped programming virtual MTRRs when running as a TDX
guest.

Link: https://lore.kernel.org/all/8137d98e-8825-415b-9282-1d2a115bb51a@linux.intel.com
Fixes: 8e690b8 ("x86/kvm: Override default caching mode for SEV-SNP and TDX")
Cc: stable@vger.kernel.org
Cc: Peter Gonda <pgonda@google.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jürgen Groß <jgross@suse.com>
Cc: Korakit Seemakhupt <korakit@google.com>
Cc: Jianxiong Gao <jxgao@google.com>
Cc: Nikolay Borisov <nik.borisov@suse.com>
Suggested-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Tested-by: Korakit Seemakhupt <korakit@google.com>
Link: https://lore.kernel.org/r/20250828005249.39339-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
github-actions bot pushed a commit to sirdarckcat/linux-1 that referenced this pull request Oct 5, 2025
We're generally not proponents of rewrites (nasty uncomfortable things
that make you late for dinner!). So why rewrite Binder?

Binder has been evolving over the past 15+ years to meet the evolving
needs of Android. Its responsibilities, expectations, and complexity
have grown considerably during that time. While we expect Binder to
continue to evolve along with Android, there are a number of factors
that currently constrain our ability to develop/maintain it. Briefly
those are:

1. Complexity: Binder is at the intersection of everything in Android and
   fulfills many responsibilities beyond IPC. It has become many things
   to many people, and due to its many features and their interactions
   with each other, its complexity is quite high. In just 6kLOC it must
   deliver transactions to the right threads. It must correctly parse
   and translate the contents of transactions, which can contain several
   objects of different types (e.g., pointers, fds) that can interact
   with each other. It controls the size of thread pools in userspace,
   and ensures that transactions are assigned to threads in ways that
   avoid deadlocks where the threadpool has run out of threads. It must
   track refcounts of objects that are shared by several processes by
   forwarding refcount changes between the processes correctly.  It must
   handle numerous error scenarios and it combines/nests 13 different
   locks, 7 reference counters, and atomic variables. Finally, It must
   do all of this as fast and efficiently as possible. Minor performance
   regressions can cause a noticeably degraded user experience.

2. Things to improve: Thousand-line functions [1], error-prone error
   handling [2], and confusing structure can occur as a code base grows
   organically. After more than a decade of development, this codebase
   could use an overhaul.

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/android/binder.c?h=v6.5#n2896
[2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/android/binder.c?h=v6.5#n3658

3. Security critical: Binder is a critical part of Android's sandboxing
   strategy. Even Android's most de-privileged sandboxes (e.g. the
   Chrome renderer, or SW Codec) have direct access to Binder. More than
   just about any other component, it's important that Binder provide
   robust security, and itself be robust against security
   vulnerabilities.

It's gregkh#1 (high complexity) that has made continuing to evolve Binder and
resolving gregkh#2 (tech debt) exceptionally difficult without causing gregkh#3
(security issues). For Binder to continue to meet Android's needs, we
need better ways to manage (and reduce!) complexity without increasing
the risk.

The biggest change is obviously the choice of programming language. We
decided to use Rust because it directly addresses a number of the
challenges within Binder that we have faced during the last years. It
prevents mistakes with ref counting, locking, bounds checking, and also
does a lot to reduce the complexity of error handling. Additionally,
we've been able to use the more expressive type system to encode the
ownership semantics of the various structs and pointers, which takes the
complexity of managing object lifetimes out of the hands of the
programmer, reducing the risk of use-after-frees and similar problems.

Rust has many different pointer types that it uses to encode ownership
semantics into the type system, and this is probably one of the most
important aspects of how it helps in Binder. The Binder driver has a lot
of different objects that have complex ownership semantics; some
pointers own a refcount, some pointers have exclusive ownership, and
some pointers just reference the object and it is kept alive in some
other manner. With Rust, we can use a different pointer type for each
kind of pointer, which enables the compiler to enforce that the
ownership semantics are implemented correctly.

Another useful feature is Rust's error handling. Rust allows for more
simplified error handling with features such as destructors, and you get
compilation failures if errors are not properly handled. This means that
even though Rust requires you to spend more lines of code than C on
things such as writing down invariants that are left implicit in C, the
Rust driver is still slightly smaller than C binder: Rust is 5.5kLOC and
C is 5.8kLOC. (These numbers are excluding blank lines, comments,
binderfs, and any debugging facilities in C that are not yet implemented
in the Rust driver. The numbers include abstractions in rust/kernel/
that are unlikely to be used by other drivers than Binder.)

Although this rewrite completely rethinks how the code is structured and
how assumptions are enforced, we do not fundamentally change *how* the
driver does the things it does. A lot of careful thought has gone into
the existing design. The rewrite is aimed rather at improving code
health, structure, readability, robustness, security, maintainability
and extensibility. We also include more inline documentation, and
improve how assumptions in the code are enforced. Furthermore, all
unsafe code is annotated with a SAFETY comment that explains why it is
correct.

We have left the binderfs filesystem component in C. Rewriting it in
Rust would be a large amount of work and requires a lot of bindings to
the file system interfaces. Binderfs has not historically had the same
challenges with security and complexity, so rewriting binderfs seems to
have lower value than the rest of Binder.

Correctness and feature parity
------------------------------

Rust binder passes all tests that validate the correctness of Binder in
the Android Open Source Project. We can boot a device, and run a variety
of apps and functionality without issues. We have performed this both on
the Cuttlefish Android emulator device, and on a Pixel 6 Pro.

As for feature parity, Rust binder currently implements all features
that C binder supports, with the exception of some debugging facilities.
The missing debugging facilities will be added before we submit the Rust
implementation upstream.

Tracepoints
-----------

I did not include all of the tracepoints as I felt that the mechansim
for making C access fields of Rust structs should be discussed on list
separately. I also did not include the support for building Rust Binder
as a module since that requires exporting a bunch of additional symbols
on the C side.

Original RFC Link with old benchmark numbers:
	https://lore.kernel.org/r/20231101-rust-binder-v1-0-08ba9197f637@google.com

Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Co-developed-by: Matt Gilbride <mattgilbride@google.com>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250919-rust-binder-v2-1-a384b09f28dd@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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