reduce hooking in TCP code #2

pabeni · 2020-03-19T10:41:04Z

the mptcp_rcv_synsent() hook can be dropped moving the related code in subflow_finish_connect()

sel_lock cannot nest in the console lock. Thanks to syzkaller, the kernel states firmly: > WARNING: possible circular locking dependency detected > 5.6.0-rc3-syzkaller #0 Not tainted > ------------------------------------------------------ > syz-executor.4/20336 is trying to acquire lock: > ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > > but task is already holding lock: > ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> multipath-tcp#2 (sel_lock){+.+.}: > mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118 > set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217 > set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181 > tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_SETSEL). Locks held on the path: console_lock -> sel_lock > -> multipath-tcp#1 (console_lock){+.+.}: > console_lock+0x46/0x70 kernel/printk/printk.c:2289 > con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223 > n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350 > do_tty_write drivers/tty/tty_io.c:962 [inline] > tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046 This is write(). Locks held on the path: termios_rwsem -> console_lock > -> #0 (&tty->termios_rwsem){++++}: > down_write+0x57/0x140 kernel/locking/rwsem.c:1534 > tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902 > tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465 > paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389 > tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_PASTESEL). Locks held on the path: sel_lock -> termios_rwsem > other info that might help us debug this: > > Chain exists of: > &tty->termios_rwsem --> console_lock --> sel_lock Clearly. From the above, we have: console_lock -> sel_lock sel_lock -> termios_rwsem termios_rwsem -> console_lock Fix this by reversing the console_lock -> sel_lock dependency in ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com Fixes: 07e6124 ("vt: selection, close sel_buffer race") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

journal_head::b_transaction and journal_head::b_next_transaction could be accessed concurrently as noticed by KCSAN, LTP: starting fsync04 /dev/zero: Can't open blockdev EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null) ================================================================== BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2] write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70: __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2] __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569 jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2] (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034 kjournald2+0x13b/0x450 [jbd2] kthread+0x1cd/0x1f0 ret_from_fork+0x27/0x50 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68: jbd2_write_access_granted+0x1b2/0x250 [jbd2] jbd2_write_access_granted at fs/jbd2/transaction.c:1155 jbd2_journal_get_write_access+0x2c/0x60 [jbd2] __ext4_journal_get_write_access+0x50/0x90 [ext4] ext4_mb_mark_diskspace_used+0x158/0x620 [ext4] ext4_mb_new_blocks+0x54f/0xca0 [ext4] ext4_ind_map_blocks+0xc79/0x1b40 [ext4] ext4_map_blocks+0x3b4/0x950 [ext4] _ext4_get_block+0xfc/0x270 [ext4] ext4_get_block+0x3b/0x50 [ext4] __block_write_begin_int+0x22e/0xae0 __block_write_begin+0x39/0x50 ext4_write_begin+0x388/0xb50 [ext4] generic_perform_write+0x15d/0x290 ext4_buffered_write_iter+0x11f/0x210 [ext4] ext4_file_write_iter+0xce/0x9e0 [ext4] new_sync_write+0x29c/0x3b0 __vfs_write+0x92/0xa0 vfs_write+0x103/0x260 ksys_write+0x9d/0x130 __x64_sys_write+0x4c/0x60 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe 5 locks held by fsync04/25724: #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260 multipath-tcp#1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4] multipath-tcp#2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2] multipath-tcp#3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4] multipath-tcp#4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2] irq event stamp: 1407125 hardirqs last enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790 softirqs last enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0 Reported by Kernel Concurrency Sanitizer on: CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ multipath-tcp#7 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 The plain reads are outside of jh->b_state_lock critical section which result in data races. Fix them by adding pairs of READ|WRITE_ONCE(). Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Qian Cai <cai@lca.pw> Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Fix NULL pointer dereference in the error flow of ib_create_qp_user when accessing to uninitialized list pointers - rdma_mrs and sig_mrs. The following crash from syzkaller revealed it. kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [multipath-tcp#1] SMP KASAN PTI CPU: 1 PID: 23167 Comm: syz-executor.1 Not tainted 5.5.0-rc5 multipath-tcp#2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 RIP: 0010:ib_mr_pool_destroy+0x81/0x1f0 Code: 00 00 fc ff df 49 c1 ec 03 4d 01 fc e8 a8 ea 72 fe 41 80 3c 24 00 0f 85 62 01 00 00 48 8b 13 48 89 d6 4c 8d 6a c8 48 c1 ee 03 <42> 80 3c 3e 00 0f 85 34 01 00 00 48 8d 7a 08 4c 8b 02 48 89 fe 48 RSP: 0018:ffffc9000951f8b0 EFLAGS: 00010046 RAX: 0000000000040000 RBX: ffff88810f268038 RCX: ffffffff82c41628 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc9000951f850 RBP: ffff88810f268020 R08: 0000000000000004 R09: fffff520012a3f0a R10: 0000000000000001 R11: fffff520012a3f0a R12: ffffed1021e4d007 R13: ffffffffffffffc8 R14: 0000000000000246 R15: dffffc0000000000 FS: 00007f54bc788700(0000) GS:ffff88811b100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000116920002 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rdma_rw_cleanup_mrs+0x15/0x30 ib_destroy_qp_user+0x674/0x7d0 ib_create_qp_user+0xb01/0x11c0 create_qp+0x1517/0x2130 ib_uverbs_create_qp+0x13e/0x190 ib_uverbs_write+0xaa5/0xdf0 __vfs_write+0x7c/0x100 vfs_write+0x168/0x4a0 ksys_write+0xc8/0x200 do_syscall_64+0x9c/0x390 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b49 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f54bc787c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000465b49 RDX: 0000000000000040 RSI: 0000000020000540 RDI: 0000000000000003 RBP: 00007f54bc787c70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f54bc7886bc R13: 00000000004ca2ec R14: 000000000070ded0 R15: 0000000000000005 Fixes: a060b56 ("IB/core: generic RDMA READ/WRITE API") Link: https://lore.kernel.org/r/20200227112708.93023-1-leon@kernel.org Signed-off-by: Maor Gottlieb <maorg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

the following packetdrill script socket(..., SOCK_STREAM, IPPROTO_MPTCP) = 3 fcntl(3, F_GETFL) = 0x2 (flags O_RDWR) fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) > S 0:0(0) <mss 1460,sackOK,TS val 100 ecr 0,nop,wscale 8,mpcapable v1 flags[flag_h] nokey> < S. 0:0(0) ack 1 win 65535 <mss 1460,sackOK,TS val 700 ecr 100,nop,wscale 8,mpcapable v1 flags[flag_h] key[skey=2]> > . 1:1(0) ack 1 win 256 <nop, nop, TS val 100 ecr 700,mpcapable v1 flags[flag_h] key[ckey,skey]> getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0 fcntl(3, F_SETFL, O_RDWR) = 0 write(3, ..., 1000) = 1000 doesn't transmit 1KB data packet after a successful three-way-handshake, using mp_capable with data as required by protocol v1, and write() hangs forever: PID: 973 TASK: ffff97dd399cae80 CPU: 1 COMMAND: "packetdrill" #0 [ffffa9b94062fb78] __schedule at ffffffff9c90a000 multipath-tcp#1 [ffffa9b94062fc08] schedule at ffffffff9c90a4a0 multipath-tcp#2 [ffffa9b94062fc18] schedule_timeout at ffffffff9c90e00d multipath-tcp#3 [ffffa9b94062fc90] wait_woken at ffffffff9c120184 multipath-tcp#4 [ffffa9b94062fcb0] sk_stream_wait_connect at ffffffff9c75b064 multipath-tcp#5 [ffffa9b94062fd20] mptcp_sendmsg at ffffffff9c8e801c multipath-tcp#6 [ffffa9b94062fdc0] sock_sendmsg at ffffffff9c747324 multipath-tcp#7 [ffffa9b94062fdd8] sock_write_iter at ffffffff9c7473c7 multipath-tcp#8 [ffffa9b94062fe48] new_sync_write at ffffffff9c302976 multipath-tcp#9 [ffffa9b94062fed0] vfs_write at ffffffff9c305685 multipath-tcp#10 [ffffa9b94062ff00] ksys_write at ffffffff9c305985 multipath-tcp#11 [ffffa9b94062ff38] do_syscall_64 at ffffffff9c004475 multipath-tcp#12 [ffffa9b94062ff50] entry_SYSCALL_64_after_hwframe at ffffffff9ca0008c RIP: 00007f959407eaf7 RSP: 00007ffe9e95a910 RFLAGS: 00000293 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f959407eaf7 RDX: 00000000000003e8 RSI: 0000000001785fe0 RDI: 0000000000000008 RBP: 0000000001785fe0 R8: 0000000000000000 R9: 0000000000000003 R10: 0000000000000007 R11: 0000000000000293 R12: 00000000000003e8 R13: 00007ffe9e95ae30 R14: 0000000000000000 R15: 0000000000000000 ORIG_RAX: 0000000000000001 CS: 0033 SS: 002b Fix it ensuring that socket state is TCP_ESTABLISHED on reception of the third ack. Fixes: 1954b86 ("mptcp: Check connection state before attempting send") Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Paul Blakey says: ==================== Introduce connection tracking offload Background ---------- The connection tracking action provides the ability to associate connection state to a packet. The connection state may be used for stateful packet processing such as stateful firewalls and NAT operations. Connection tracking in TC SW ---------------------------- The CT state may be matched only after the CT action is performed. As such, CT use cases are commonly implemented using multiple chains. Consider the following TC filters, as an example: 1. tc filter add dev ens1f0_0 ingress prio 1 chain 0 proto ip flower \ src_mac 24:8a:07:a5:28:01 ct_state -trk \ action ct \ pipe action goto chain 2 2. tc filter add dev ens1f0_0 ingress prio 1 chain 2 proto ip flower \ ct_state +trk+new \ action ct commit \ pipe action tunnel_key set \ src_ip 0.0.0.0 \ dst_ip 7.7.7.8 \ id 98 \ dst_port 4789 \ action mirred egress redirect dev vxlan0 3. tc filter add dev ens1f0_0 ingress prio 1 chain 2 proto ip flower \ ct_state +trk+est \ action tunnel_key set \ src_ip 0.0.0.0 \ dst_ip 7.7.7.8 \ id 98 \ dst_port 4789 \ action mirred egress redirect dev vxlan0 Filter multipath-tcp#1 (chain 0) decides, after initial packet classification, to send the packet to the connection tracking module (ct action). Once the ct_state is initialized by the CT action the packet processing continues on chain 2. Chain 2 classifies the packet based on the ct_state. Filter multipath-tcp#2 matches on the +trk+new CT state while filter multipath-tcp#3 matches on the +trk+est ct_state. MLX5 Connection tracking HW offload - MLX5 driver patches ------------------------------ The MLX5 hardware model aligns with the software model by realizing a multi-table architecture. In SW the TC CT action sets the CT state on the skb. Similarly, HW sets the CT state on a HW register. Driver gets this CT state while offloading a tuple with a new ct_metadata action that provides it. Matches on ct_state are translated to HW register matches. TC filter with CT action broken to two rules, a pre_ct rule, and a post_ct rule. pre_ct rule: Inserted on the corrosponding tc chain table, matches on original tc match, with actions: any pre ct actions, set fte_id, set zone, and goto the ct table. The fte_id is a register mapping uniquely identifying this filter. post_ct_rule: Inserted in a post_ct table, matches on the fte_id register mapping, with actions: counter + any post ct actions (this is usally 'goto chain X') post_ct table is a table that all the tuples inserted to the ct table goto, so if there is a tuple hit, packet will continue from ct table to post_ct table, after being marked with the CT state (mark/label..) This design ensures that the rule's actions and counters will be executed only after a CT hit. HW misses will continue processing in SW from the last chain ID that was processed in hardware. The following illustrates the HW model: +-------------------+ +--------------------+ +--------------+ + pre_ct (tc chain) +----->+ CT (nat or no nat) +--->+ post_ct +-----> + original match + | + tuple + zone match + | + fte_id match + | +-------------------+ | +--------------------+ | +--------------+ | v v v set chain miss mapping set mark original set fte_id set label filter set zone set established actions set tunnel_id do nat (if needed) do decap To fill CT table, driver registers a CB for flow offload events, for each new flow table that is passed to it from offloading ct actions. Once a flow offload event is triggered on this CB, offload this flow to the hardware CT table. Established events offload -------------------------- Currently, act_ct maintains an FT instance per ct zone. Flow table entries are created, per ct connection, when connections enter an established state and deleted otherwise. Once an entry is created, the FT assumes ownership of the entries, and manages their aging. FT is used for software offload of conntrack. FT entries associate 5-tuples with an action list. The act_ct changes in this patchset: Populate the action list with a (new) ct_metadata action, providing the connection's ct state (zone,mark and label), and mangle actions if NAT is configured. Pass the action's flow table instance as ct action entry parameter, so when the action is offloaded, the driver may register a callback on it's block to receive FT flow offload add/del/stats events. Netilter changes -------------------------- The netfilter changes export the relevant bits, and add the relevant CBs to support the above. Applying this patchset -------------------------- On top of current net-next ("r8169: simplify getting stats by using netdev_stats_to_stats64"), pull Saeed's ct-offload branch, from git git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux.git and fix the following non trivial conflict in fs_core.c as follows: Then apply this patchset. Changelog: v2->v3: Added the first two patches needed after rebasing on net-next: "net/mlx5: E-Switch, Enable reg c1 loopback when possible" "net/mlx5e: en_rep: Create uplink rep root table after eswitch offloads table" ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Sigh, this is mostly my fault for not giving commit cd82d82 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check") enough scrutiny during review. The way we're checking bandwidth limitations here is mostly wrong: For starters, drm_dp_mst_atomic_check_bw_limit() determines the pbn_limit of a branch by simply scanning each port on the current branch device, then uses the last non-zero full_pbn value that it finds. It then counts the sum of the PBN used on each branch device for that level, and compares against the full_pbn value it found before. This is wrong because ports can and will have different PBN limitations on many hubs, especially since a number of DisplayPort hubs out there will be clever and only use the smallest link rate required for each downstream sink - potentially giving every port a different full_pbn value depending on what link rate it's trained at. This means with our current code, which max PBN value we end up with is not well defined. Additionally, we also need to remember when checking bandwidth limitations that the top-most device in any MST topology is a branch device, not a port. This means that the first level of a topology doesn't technically have a full_pbn value that needs to be checked. Instead, we should assume that so long as our VCPI allocations fit we're within the bandwidth limitations of the primary MSTB. We do however, want to check full_pbn on every port including those of the primary MSTB. However, it's important to keep in mind that this value represents the minimum link rate /between a port's sink or mstb, and the mstb itself/. A quick diagram to explain: MSTB multipath-tcp#1 / \ / \ Port multipath-tcp#1 Port multipath-tcp#2 full_pbn for Port multipath-tcp#1 → | | ← full_pbn for Port multipath-tcp#2 Sink multipath-tcp#1 MSTB multipath-tcp#2 | etc... Note that in the above diagram, the combined PBN from all VCPI allocations on said hub should not exceed the full_pbn value of port multipath-tcp#2, and the display configuration on sink multipath-tcp#1 should not exceed the full_pbn value of port multipath-tcp#1. However, port multipath-tcp#1 and port multipath-tcp#2 can otherwise consume as much bandwidth as they want so long as their VCPI allocations still fit. And finally - our current bandwidth checking code also makes the mistake of not checking whether something is an end device or not before trying to traverse down it. So, let's fix it by rewriting our bandwidth checking helpers. We split the function into one part for handling branches which simply adds up the total PBN on each branch and returns it, and one for checking each port to ensure we're not going over its PBN limit. Phew. This should fix regressions seen, where we erroneously reject display configurations due to thinking they're going over our bandwidth limits when they're not. Changes since v1: * Took an even closer look at how PBN limitations are supposed to be handled, and did some experimenting with Sean Paul. Ended up rewriting these helpers again, but this time they should actually be correct! Changes since v2: * Small indenting fix * Fix pbn_used check in drm_dp_mst_atomic_check_port_bw_limit() Signed-off-by: Lyude Paul <lyude@redhat.com> Fixes: cd82d82 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check") Cc: Sean Paul <seanpaul@google.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Mikita Lipski <mikita.lipski@amd.com> Tested-by: Hans de Goede <hdegoede@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200309210131.1497545-1-lyude@redhat.com

Petr Machata says: ==================== RED: Introduce an ECN tail-dropping mode When the RED qdisc is currently configured to enable ECN, the RED algorithm is used to decide whether a certain SKB should be marked. If that SKB is not ECN-capable, it is early-dropped. It is also possible to keep all traffic in the queue, and just mark the ECN-capable subset of it, as appropriate under the RED algorithm. Some switches support this mode, and some installations make use of it. There is currently no way to put the RED qdiscs to this mode. Therefore this patchset adds a new RED flag, TC_RED_TAILDROP. When the qdisc is configured with this flag, non-ECT traffic is enqueued (and tail-dropped when the queue size is exhausted) instead of being early-dropped. Unfortunately, adding a new RED flag is not as simple as it sounds. RED flags are passed in tc_red_qopt.flags. However RED neglects to validate the flag field, and just copies it over wholesale to its internal structure, and later dumps it back. A broken userspace can therefore configure a RED qdisc with arbitrary unsupported flags, and later expect to see the flags on qdisc dump. The current ABI thus allows storage of 5 bits of custom data along with the qdisc instance. GRED, SFQ and CHOKE qdiscs are in the same situation. (GRED validates VQ flags, but not the flags for the main queue.) E.g. if SFQ ever needs to support TC_RED_ADAPTATIVE, it needs another way of doing it, and at the same time it needs to retain the possibility to store 6 bits of uninterpreted data. For RED, this problem is resolved in patch multipath-tcp#2, which adds a new attribute, and a way to separate flags from userbits that can be reused by other qdiscs. The flag itself and related behavioral changes are added in patch To test the new feature, patch multipath-tcp#1 first introduces a TDC testsuite that covers the existing RED flags. Patch multipath-tcp#5 later extends it with taildrop coverage. Patch multipath-tcp#6 contains a forwarding selftest for the offloaded datapath. To test the SW datapath, I took the mlxsw selftest and adapted it in mostly obvious ways. The test is stable enough to verify that RED, ECN and ECN taildrop actually work. However, I have no confidence in its portability to other people's machines or mildly different configurations. I therefore do not find it suitable for upstreaming. GRED and CHOKE can use the same method as RED if they ever need to support extra flags. SFQ uses the length of TCA_OPTIONS to dispatch on binary control structure version, and would therefore need a different approach. v2: - Patch multipath-tcp#1 - Require nsPlugin in each RED test - Match end-of-line to catch cases of more flags reported than requested - Patch multipath-tcp#2: - Replaced with another patch. - Patch multipath-tcp#3: - Fix red_use_taildrop() condition in red_enqueue switch for probabilistic case. - Patch multipath-tcp#5: - Require nsPlugin in each RED test - Match end-of-line to catch cases of more flags reported than requested - Add a test for creation of non-ECN taildrop, which should fail ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says: ==================== mlxsw: Offload TC action skbedit priority Petr says: The TC action "skbedit priority P" has the effect of assigning skbprio of P to SKBs that it's applied on. In HW datapath of a switch, the corresponding action is assignment of internal switch priority. Spectrum switches allow setting of packet priority based on an ACL action, which is good match for the skbedit priority gadget. This patchset therefore implements offloading of this action to the Spectrum ACL engine. After a bit of refactoring in patch #1, patch #2 extends the skbedit action to support offloading of "priority" subcommand. On mlxsw side, in patch #3, the QOS_ACTION flexible action is added, with fields necessary for priority adjustment. In patch #4, "skbedit priority" is connected to that action. Patch #5 implements a new forwarding selftest, suitable for both SW- and HW-datapath testing. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

The DMA error handler routine is currently a tasklet, scheduled to run after the DMA error IRQ was handled. However it needs to take the MDIO mutex, which is not allowed to do in a tasklet. A kernel (with debug options) complains consequently: [ 614.050361] net eth0: DMA Tx error 0x174019 [ 614.064002] net eth0: Current BD is at: 0x8f84aa0ce [ 614.080195] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 [ 614.109484] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 40, name: kworker/u4:4 [ 614.135428] 3 locks held by kworker/u4:4/40: [ 614.149075] #0: ffff000879863328 ((wq_completion)rpciod){....}, at: process_one_work+0x1f0/0x6a8 [ 614.177528] #1: ffff80001251bdf8 ((work_completion)(&task->u.tk_work)){....}, at: process_one_work+0x1f0/0x6a8 [ 614.209033] #2: ffff0008784e0110 (sk_lock-AF_INET-RPC){....}, at: tcp_sendmsg+0x24/0x58 [ 614.235429] CPU: 0 PID: 40 Comm: kworker/u4:4 Not tainted 5.6.0-rc3-00926-g4a165a9d5921 #26 [ 614.260854] Hardware name: ARM Test FPGA (DT) [ 614.274734] Workqueue: rpciod rpc_async_schedule [ 614.289022] Call trace: [ 614.296871] dump_backtrace+0x0/0x1a0 [ 614.308311] show_stack+0x14/0x20 [ 614.318751] dump_stack+0xbc/0x100 [ 614.329403] ___might_sleep+0xf0/0x140 [ 614.341018] __might_sleep+0x4c/0x80 [ 614.352201] __mutex_lock+0x5c/0x8a8 [ 614.363348] mutex_lock_nested+0x1c/0x28 [ 614.375654] axienet_dma_err_handler+0x38/0x388 [ 614.389999] tasklet_action_common.isra.15+0x160/0x1a8 [ 614.405894] tasklet_action+0x24/0x30 [ 614.417297] efi_header_end+0xe0/0x494 [ 614.429020] irq_exit+0xd0/0xd8 [ 614.439047] __handle_domain_irq+0x60/0xb0 [ 614.451877] gic_handle_irq+0xdc/0x2d0 [ 614.463486] el1_irq+0xcc/0x180 [ 614.473451] __tcp_transmit_skb+0x41c/0xb58 [ 614.486513] tcp_write_xmit+0x224/0x10a0 [ 614.498792] __tcp_push_pending_frames+0x38/0xc8 [ 614.513126] tcp_rcv_established+0x41c/0x820 [ 614.526301] tcp_v4_do_rcv+0x8c/0x218 [ 614.537784] __release_sock+0x5c/0x108 [ 614.549466] release_sock+0x34/0xa0 [ 614.560318] tcp_sendmsg+0x40/0x58 [ 614.571053] inet_sendmsg+0x40/0x68 [ 614.582061] sock_sendmsg+0x18/0x30 [ 614.593074] xs_sendpages+0x218/0x328 [ 614.604506] xs_tcp_send_request+0xa0/0x1b8 [ 614.617461] xprt_transmit+0xc8/0x4f0 [ 614.628943] call_transmit+0x8c/0xa0 [ 614.640028] __rpc_execute+0xbc/0x6f8 [ 614.651380] rpc_async_schedule+0x28/0x48 [ 614.663846] process_one_work+0x298/0x6a8 [ 614.676299] worker_thread+0x40/0x490 [ 614.687687] kthread+0x134/0x138 [ 614.697804] ret_from_fork+0x10/0x18 [ 614.717319] xilinx_axienet 7fe00000.ethernet eth0: Link is Down [ 615.748343] xilinx_axienet 7fe00000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off Since tasklets are not really popular anymore anyway, lets convert this over to a work queue, which can sleep and thus can take the MDIO mutex. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Yonghong Song says: ==================== Commit 8b401f9 ("bpf: implement bpf_send_signal() helper") introduced bpf_send_signal() helper and Commit 8482941 ("bpf: Add bpf_send_signal_thread() helper") added bpf_send_signal_thread() helper. Both helpers try to send a signel to current process or thread. When bpf_prog is called with scheduler rq_lock held, a deadlock could happen since bpf_send_signal() and bpf_send_signal_thread() will call group_send_sig_info() which may ultimately want to acquire rq_lock() again. This happens in 5.2 and 4.16 based kernels in our production environment with perf_sw_event. In a different scenario, the following is also possible in the last kernel: cpu 1: do_task_stat <- holding sighand->siglock ... task_sched_runtime <- trying to grab rq_lock cpu 2: __schedule <- holding rq_lock ... do_send_sig_info <- trying to grab sighand->siglock Commit eac9153 ("bpf/stackmap: Fix deadlock with rq_lock in bpf_get_stack()") has a similar issue with above rq_lock() deadlock. This patch set addressed the issue in a similar way. Patch #1 provided kernel solution and Patch #2 added a selftest. Changelogs: v2 -> v3: . simplify selftest send_signal_sched_switch(). The previous version has mmap/munmap inherited from Song's reproducer. They are not necessary in this context. v1 -> v2: . previous fix using task_work in nmi() is incorrect. there is no nmi() involvement here. Using task_work in all cases might be a solution. But decided to use a similar fix as in Commit eac9153. ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>

The bucket->lock is not needed in the sock_hash_free and sock_map_free calls, in fact it is causing a splat due to being inside rcu block. | BUG: sleeping function called from invalid context at net/core/sock.c:2935 | in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 62, name: kworker/0:1 | 3 locks held by kworker/0:1/62: | #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0 | #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0 | #2: ffff8881381f6df8 (&stab->lock){+...}, at: sock_map_free+0x26/0x180 | CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04008-g7b083332376e #454 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 | Workqueue: events bpf_map_free_deferred | Call Trace: | dump_stack+0x71/0xa0 | ___might_sleep.cold+0xa6/0xb6 | lock_sock_nested+0x28/0x90 | sock_map_free+0x5f/0x180 | bpf_map_free_deferred+0x58/0x80 | process_one_work+0x260/0x5e0 | worker_thread+0x4d/0x3e0 | kthread+0x108/0x140 | ? process_one_work+0x5e0/0x5e0 | ? kthread_park+0x90/0x90 | ret_from_fork+0x3a/0x50 The reason we have stab->lock and bucket->locks in sockmap code is to handle checking EEXIST in update/delete cases. We need to be careful during an update operation that we check for EEXIST and we need to ensure that the psock object is not in some partial state of removal/insertion while we do this. So both map_update_common and sock_map_delete need to guard from being run together potentially deleting an entry we are checking, etc. But by the time we get to the tear-down code in sock_{ma[|hash}_free we have already disconnected the map and we just did synchronize_rcu() in the line above so no updates/deletes should be in flight. Because of this we can drop the bucket locks from the map free'ing code, noting no update/deletes can be in-flight. Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface") Reported-by: Jakub Sitnicki <jakub@cloudflare.com> Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/158385850787.30597.8346421465837046618.stgit@john-Precision-5820-Tower

The vector management code assumes that managed interrupts cannot be migrated away from an online CPU. free_moved_vector() has a WARN_ON_ONCE() which triggers when a managed interrupt vector association on a online CPU is cleared. The CPU offline code uses a different mechanism which cannot trigger this. This assumption is not longer correct because the new CPU isolation feature which affects the placement of managed interrupts must be able to move a managed interrupt away from an online CPU. There are two reasons why this can happen: 1) When the interrupt is activated the affinity mask which was established in irq_create_affinity_masks() is handed in to the vector allocation code. This mask contains all CPUs to which the interrupt can be made affine to, but this does not take the CPU isolation 'managed_irq' mask into account. When the interrupt is finally requested by the device driver then the affinity is checked again and the CPU isolation 'managed_irq' mask is taken into account, which moves the interrupt to a non-isolated CPU if possible. 2) The interrupt can be affine to an isolated CPU because the non-isolated CPUs in the calculated affinity mask are not online. Once a non-isolated CPU which is in the mask comes online the interrupt is migrated to this non-isolated CPU In both cases the regular online migration mechanism is used which triggers the WARN_ON_ONCE() in free_moved_vector(). Case #1 could have been addressed by taking the isolation mask into account, but that would require a massive code change in the activation logic and the eventual migration event was accepted as a reasonable tradeoff when the isolation feature was developed. But even if #1 would be addressed, #2 would still trigger it. Of course the warning in free_moved_vector() was overlooked at that time and the above two cases which have been discussed during patch review have obviously never been tested before the final submission. So keep it simple and remove the warning. [ tglx: Rewrote changelog and added a comment to free_moved_vector() ] Fixes: 11ea68f ("genirq, sched/isolation: Isolate from handling managed interrupts") Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lkml.kernel.org/r/20200312205830.81796-1-peterx@redhat.com

It is safe to traverse mm->notifier_subscriptions->list either under SRCU read lock or mm->notifier_subscriptions->lock using hlist_for_each_entry_rcu(). Silence the PROVE_RCU_LIST false positives, for example, WARNING: suspicious RCU usage ----------------------------- mm/mmu_notifier.c:484 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by libvirtd/802: #0: ffff9321e3f58148 (&mm->mmap_sem#2){++++}, at: do_mprotect_pkey+0xe1/0x3e0 #1: ffffffff91ae6160 (mmu_notifier_invalidate_range_start){+.+.}, at: change_p4d_range+0x5fa/0x800 #2: ffffffff91ae6e08 (srcu){....}, at: __mmu_notifier_invalidate_range_start+0x178/0x460 stack backtrace: CPU: 7 PID: 802 Comm: libvirtd Tainted: G I 5.6.0-rc6-next-20200317+ #2 Hardware name: HP ProLiant BL460c Gen8, BIOS I31 11/02/2014 Call Trace: dump_stack+0xa4/0xfe lockdep_rcu_suspicious+0xeb/0xf5 __mmu_notifier_invalidate_range_start+0x3ff/0x460 change_p4d_range+0x746/0x800 change_protection+0x1df/0x300 mprotect_fixup+0x245/0x3e0 do_mprotect_pkey+0x23b/0x3e0 __x64_sys_mprotect+0x51/0x70 do_syscall_64+0x91/0xae8 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Link: http://lkml.kernel.org/r/20200317175640.2047-1-cai@lca.pw Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Ido Schimmel says: ==================== mlxsw: Offload TC action pedit munge dsfield Petr says: The Spectrum switches allow packet prioritization based on DSCP on ingress, and update of DSCP on egress. This is configured through the DCB APP rules. For some use cases, assigning a custom DSCP value based on an ACL match is a better tool. To that end, offload FLOW_ACTION_MANGLE to permit changing of dsfield as a whole, or DSCP and ECN values in isolation. After fixing a commentary nit in patch #1, and mlxsw naming in patch #2, patches #3 and #4 add the offload to mlxsw. Patch #5 adds a forwarding selftest for pedit dsfield, applicable to SW as well as HW datapaths. Patch #6 adds a mlxsw-specific test to verify DSCP rewrite due to DCB APP rules is not performed on pedited packets. The tests only cover IPv4 dsfield setting. We have tests for IPv6 as well, but would like to postpone their contribution until the corresponding iproute patches have been accepted. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Petr Machata says: ==================== Implement stats_update callback for pedit and skbedit The stats_update callback is used for adding HW counters to the SW ones. Both skbedit and pedit actions are actually recognized by flow_offload.h, but do not implement these callbacks. As a consequence, the reported values are only the SW ones, even where there is a HW counter available. Patch #1 adds the callback to action skbedit, patch #2 adds it to action pedit. Patch #3 tweaks an skbedit selftest with a check that would have caught this problem. The pedit test is not likewise tweaked, because the iproute2 pedit action currently does not support JSON dumping. This will be addressed later. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says: ==================== mlxsw: Various static checkers fixes Jakub told me he gets some warnings with W=1, so I decided to check with sparse, smatch and coccinelle as well. This patch set fixes all the issues found. None are actual bugs / regressions and therefore not targeted at net. Patches #1-#2 add missing kernel-doc comments. Patch #3 removes dead code. Patch #4 reworks the ACL code to avoid defining a static variable in a header file. Patch #5 removes unnecessary conversion to bool that coccinelle warns about. Patch #6 avoids false-positive uninitialized symbol errors emitted by smatch. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says: ==================== Add packet trap policers support Background ========== Devices capable of offloading the kernel's datapath and perform functions such as bridging and routing must also be able to send (trap) specific packets to the kernel (i.e., the CPU) for processing. For example, a device acting as a multicast-aware bridge must be able to trap IGMP membership reports to the kernel for processing by the bridge module. Motivation ========== In most cases, the underlying device is capable of handling packet rates that are several orders of magnitude higher compared to those that can be handled by the CPU. Therefore, in order to prevent the underlying device from overwhelming the CPU, devices usually include packet trap policers that are able to police the trapped packets to rates that can be handled by the CPU. Proposed solution ================= This patch set allows capable device drivers to register their supported packet trap policers with devlink. User space can then tune the parameters of these policers (currently, rate and burst size) and read from the device the number of packets that were dropped by the policer, if supported. These packet trap policers can then be bound to existing packet trap groups, which are used to aggregate logically related packet traps. As a result, trapped packets are policed to rates that can be handled the host CPU. Example usage ============= Instantiate netdevsim: Dump available packet trap policers: netdevsim/netdevsim10: policer 1 rate 1000 burst 128 policer 2 rate 2000 burst 256 policer 3 rate 3000 burst 512 Change the parameters of a packet trap policer: Bind a packet trap policer to a packet trap group: Dump parameters and statistics of a packet trap policer: netdevsim/netdevsim10: policer 3 rate 100 burst 16 stats: rx: dropped 92 Unbind a packet trap policer from a packet trap group: Patch set overview ================== Patch #1 adds the core infrastructure in devlink which allows capable device drivers to register their supported packet trap policers with devlink. Patch #2 extends the existing devlink-trap documentation. Patch #3 extends netdevsim to register a few dummy packet trap policers with devlink. Used later on to selftests the core infrastructure. Patches #4-#5 adds infrastructure in devlink to allow binding of packet trap policers to packet trap groups. Patch #6 extends netdevsim to allow such binding. Patch #7 adds a selftest over netdevsim that verifies the core devlink-trap policers functionality. Patches #8-#14 gradually add devlink-trap policers support in mlxsw. Patch #15 adds a selftest over mlxsw. All registered packet trap policers are verified to handle the configured rate and burst size. Future plans ============ * Allow changing default association between packet traps and packet trap groups * Add more packet traps. For example, for control packets (e.g., IGMP) v3: * Rebase v2 (address comments from Jiri and Jakub): * Patch #1: Add 'strict_start_type' in devlink policy * Patch #1: Have device drivers provide max/min rate/burst size for each policer. Use them to check validity of user provided parameters * Patch #3: Remove check about burst size being a power of 2 and instead add a debugfs knob to fail the operation * Patch #3: Provide max/min rate/burst size when registering policers and remove the validity checks from nsim_dev_devlink_trap_policer_set() * Patch #5: Check for presence of 'DEVLINK_ATTR_TRAP_POLICER_ID' in devlink_trap_group_set() and bail if not present * Patch #5: Add extack error message in case trap group was partially modified * Patch #7: Add test case with new 'fail_trap_policer_set' knob * Patch #7: Add test case for partially modified trap group * Patch #10: Provide max/min rate/burst size when registering policers * Patch #11: Remove the max/min validity checks from __mlxsw_sp_trap_policer_set() ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Fainelli says: ==================== net: dsa: b53 & bcm_sf2 updates for 7278 This patch series contains some updates to the b53 and bcm_sf2 drivers specifically for the 7278 Ethernet switch. The first patch is technically a bug fix so it should ideally be backported to -stable, provided that Dan also agress with my resolution on this. Patches #2 through #4 are minor changes to the core b53 driver to restore VLAN configuration upon system resumption as well as deny specific bridge/VLAN operations on port 7 with the 7278 which is special and does not support VLANs. Patches #5 through #9 add support for matching VLAN TCI keys/masks to the CFP code. Changes in v2: - fixed some code comments and arrange some code for easier reading ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

With the following patches: - btrfs: backref, only collect file extent items matching backref offset - btrfs: backref, not adding refs from shared block when resolving normal backref - btrfs: backref, only search backref entries from leaves of the same root we only collect the normal data refs we want, so the imprecise upper bound total_refs of that EXTENT_ITEM could now be changed to the count of the normal backref entry we want to search. Background and how the patches fit together: Btrfs has two types of data backref. For BTRFS_EXTENT_DATA_REF_KEY type of backref, we don't have the exact block number. Therefore, we need to call resolve_indirect_refs. It uses btrfs_search_slot to locate the leaf block. Then we need to walk through the leaves to search for the EXTENT_DATA items that have disk bytenr matching the extent item (add_all_parents). When resolving indirect refs, we could take entries that don't belong to the backref entry we are searching for right now. For that reason when searching backref entry, we always use total refs of that EXTENT_ITEM rather than individual count. For example: item 11 key (40831553536 EXTENT_ITEM 4194304) itemoff 15460 itemsize extent refs 24 gen 7302 flags DATA shared data backref parent 394985472 count 10 #1 extent data backref root 257 objectid 260 offset 1048576 count 3 #2 extent data backref root 256 objectid 260 offset 65536 count 6 #3 extent data backref root 257 objectid 260 offset 65536 count 5 #4 For example, when searching backref entry #4, we'll use total_refs 24, a very loose loop ending condition, instead of total_refs = 5. But using total_refs = 24 is not accurate. Sometimes, we'll never find all the refs from specific root. As a result, the loop keeps on going until we reach the end of that inode. The first 3 patches, handle 3 different types refs we might encounter. These refs do not belong to the normal backref we are searching, and hence need to be skipped. This patch changes the total_refs to correct number so that we could end loop as soon as we find all the refs we want. btrfs send uses backref to find possible clone sources, the following is a simple test to compare the results with and without this patch: $ btrfs subvolume create /sub1 $ for i in `seq 1 163840`; do dd if=/dev/zero of=/sub1/file bs=64K count=1 seek=$((i-1)) conv=notrunc oflag=direct done $ btrfs subvolume snapshot /sub1 /sub2 $ for i in `seq 1 163840`; do dd if=/dev/zero of=/sub1/file bs=4K count=1 seek=$(((i-1)*16+10)) conv=notrunc oflag=direct done $ btrfs subvolume snapshot -r /sub1 /snap1 $ time btrfs send /snap1 | btrfs receive /volume2 Without this patch: real 69m48.124s user 0m50.199s sys 70m15.600s With this patch: real 1m59.683s user 0m35.421s sys 2m42.684s Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: ethanwu <ethanwu@synology.com> [ add patchset cover letter with background and numbers ] Signed-off-by: David Sterba <dsterba@suse.com>

During unmount we can have a job from the delayed inode items work queue still running, that can lead to at least two bad things: 1) A crash, because the worker can try to create a transaction just after the fs roots were freed; 2) A transaction leak, because the worker can create a transaction before the fs roots are freed and just after we committed the last transaction and after we stopped the transaction kthread. A stack trace example of the crash: [79011.691214] kernel BUG at lib/radix-tree.c:982! [79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G W 5.6.0-rc2-btrfs-next-54 #2 (...) [79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs] [79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170 (...) [79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293 [79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0 [79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0 [79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000 [79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001 [79011.709270] FS: 0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000 [79011.710699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0 [79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [79011.715448] Call Trace: [79011.715925] record_root_in_trans+0x72/0xf0 [btrfs] [79011.716819] btrfs_record_root_in_trans+0x4b/0x70 [btrfs] [79011.717925] start_transaction+0xdd/0x5c0 [btrfs] [79011.718829] btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs] [79011.719915] btrfs_work_helper+0xaa/0x720 [btrfs] [79011.720773] process_one_work+0x26d/0x6a0 [79011.721497] worker_thread+0x4f/0x3e0 [79011.722153] ? process_one_work+0x6a0/0x6a0 [79011.722901] kthread+0x103/0x140 [79011.723481] ? kthread_create_worker_on_cpu+0x70/0x70 [79011.724379] ret_from_fork+0x3a/0x50 (...) The following diagram shows a sequence of steps that lead to the crash during ummount of the filesystem: CPU 1 CPU 2 CPU 3 btrfs_punch_hole() btrfs_btree_balance_dirty() btrfs_balance_delayed_items() --> sees fs_info->delayed_root->items with value 200, which is greater than BTRFS_DELAYED_BACKGROUND (128) and smaller than BTRFS_DELAYED_WRITEBACK (512) btrfs_wq_run_delayed_node() --> queues a job for fs_info->delayed_workers to run btrfs_async_run_delayed_root() btrfs_async_run_delayed_root() --> job queued by CPU 1 --> starts picking and running delayed nodes from the prepare_list list close_ctree() btrfs_delete_unused_bgs() btrfs_commit_super() btrfs_join_transaction() --> gets transaction N btrfs_commit_transaction(N) --> set transaction state to TRANTS_STATE_COMMIT_START btrfs_first_prepared_delayed_node() --> picks delayed node X through the prepared_list list btrfs_run_delayed_items() btrfs_first_delayed_node() --> also picks delayed node X but through the node_list list __btrfs_commit_inode_delayed_items() --> runs all delayed items from this node and drops the node's item count to 0 through call to btrfs_release_delayed_inode() --> finishes running any remaining delayed nodes --> finishes transaction commit --> stops cleaner and transaction threads btrfs_free_fs_roots() --> frees all roots and removes them from the radix tree fs_info->fs_roots_radix btrfs_join_transaction() start_transaction() btrfs_record_root_in_trans() record_root_in_trans() radix_tree_tag_set() --> crashes because the root is not in the radix tree anymore If the worker is able to call btrfs_join_transaction() before the unmount task frees the fs roots, we end up leaking a transaction and all its resources, since after the call to btrfs_commit_super() and stopping the transaction kthread, we don't expect to have any transaction open anymore. When this situation happens the worker has a delayed node that has no more items to run, since the task calling btrfs_run_delayed_items(), which is doing a transaction commit, picks the same node and runs all its items first. We can not wait for the worker to complete when running delayed items through btrfs_run_delayed_items(), because we call that function in several phases of a transaction commit, and that could cause a deadlock because the worker calls btrfs_join_transaction() and the task doing the transaction commit may have already set the transaction state to TRANS_STATE_COMMIT_DOING. Also it's not possible to get into a situation where only some of the items of a delayed node are added to the fs/subvolume tree in the current transaction and the remaining ones in the next transaction, because when running the items of a delayed inode we lock its mutex, effectively waiting for the worker if the worker is running the items of the delayed node already. Since this can only cause issues when unmounting a filesystem, fix it in a simple way by waiting for any jobs on the delayed workers queue before calling btrfs_commit_supper() at close_ctree(). This works because at this point no one can call btrfs_btree_balance_dirty() or btrfs_balance_delayed_items(), and if we end up waiting for any worker to complete, btrfs_commit_super() will commit the transaction created by the worker. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

…during probe When booting j721e the following bug is printed: [ 1.154821] BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 [ 1.154827] in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 12, name: kworker/0:1 [ 1.154832] 3 locks held by kworker/0:1/12: [ 1.154836] #0: ffff000840030728 ((wq_completion)events){+.+.}, at: process_one_work+0x1d4/0x6e8 [ 1.154852] #1: ffff80001214fdd8 (deferred_probe_work){+.+.}, at: process_one_work+0x1d4/0x6e8 [ 1.154860] #2: ffff00084060b170 (&dev->mutex){....}, at: __device_attach+0x38/0x138 [ 1.154872] irq event stamp: 63096 [ 1.154881] hardirqs last enabled at (63095): [<ffff800010b74318>] _raw_spin_unlock_irqrestore+0x70/0x78 [ 1.154887] hardirqs last disabled at (63096): [<ffff800010b740d8>] _raw_spin_lock_irqsave+0x28/0x80 [ 1.154893] softirqs last enabled at (62254): [<ffff800010080c88>] _stext+0x488/0x564 [ 1.154899] softirqs last disabled at (62247): [<ffff8000100fdb3c>] irq_exit+0x114/0x140 [ 1.154906] CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.6.0-rc6-next-20200318-00094-g45e4089b0bd3 #221 [ 1.154911] Hardware name: Texas Instruments K3 J721E SoC (DT) [ 1.154917] Workqueue: events deferred_probe_work_func [ 1.154923] Call trace: [ 1.154928] dump_backtrace+0x0/0x190 [ 1.154933] show_stack+0x14/0x20 [ 1.154940] dump_stack+0xe0/0x148 [ 1.154946] ___might_sleep+0x150/0x1f0 [ 1.154952] __might_sleep+0x4c/0x80 [ 1.154957] wait_for_completion_timeout+0x40/0x140 [ 1.154964] ti_sci_set_device_state+0xa0/0x158 [ 1.154969] ti_sci_cmd_get_device_exclusive+0x14/0x20 [ 1.154977] ti_sci_dev_start+0x34/0x50 [ 1.154984] genpd_runtime_resume+0x78/0x1f8 [ 1.154991] __rpm_callback+0x3c/0x140 [ 1.154996] rpm_callback+0x20/0x80 [ 1.155001] rpm_resume+0x568/0x758 [ 1.155007] __pm_runtime_resume+0x44/0xb0 [ 1.155013] omap8250_probe+0x2b4/0x508 [ 1.155019] platform_drv_probe+0x50/0xa0 [ 1.155023] really_probe+0xd4/0x318 [ 1.155028] driver_probe_device+0x54/0xe8 [ 1.155033] __device_attach_driver+0x80/0xb8 [ 1.155039] bus_for_each_drv+0x74/0xc0 [ 1.155044] __device_attach+0xdc/0x138 [ 1.155049] device_initial_probe+0x10/0x18 [ 1.155053] bus_probe_device+0x98/0xa0 [ 1.155058] deferred_probe_work_func+0x74/0xb0 [ 1.155063] process_one_work+0x280/0x6e8 [ 1.155068] worker_thread+0x48/0x430 [ 1.155073] kthread+0x108/0x138 [ 1.155079] ret_from_fork+0x10/0x18 To fix the bug we need to first call pm_runtime_enable() prior to any pm_runtime calls. Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Link: https://lore.kernel.org/r/20200320125200.6772-1-peter.ujfalusi@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Zygo reported the following lockdep splat while testing the balance patches ====================================================== WARNING: possible circular locking dependency detected 5.6.0-c6f0579d496a+ #53 Not tainted ------------------------------------------------------ kswapd0/1133 is trying to acquire lock: ffff888092f622c0 (&delayed_node->mutex){+.+.}, at: __btrfs_release_delayed_node+0x7c/0x5b0 but task is already holding lock: ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}: fs_reclaim_acquire.part.91+0x29/0x30 fs_reclaim_acquire+0x19/0x20 kmem_cache_alloc_trace+0x32/0x740 add_block_entry+0x45/0x260 btrfs_ref_tree_mod+0x6e2/0x8b0 btrfs_alloc_tree_block+0x789/0x880 alloc_tree_block_no_bg_flush+0xc6/0xf0 __btrfs_cow_block+0x270/0x940 btrfs_cow_block+0x1ba/0x3a0 btrfs_search_slot+0x999/0x1030 btrfs_insert_empty_items+0x81/0xe0 btrfs_insert_delayed_items+0x128/0x7d0 __btrfs_run_delayed_items+0xf4/0x2a0 btrfs_run_delayed_items+0x13/0x20 btrfs_commit_transaction+0x5cc/0x1390 insert_balance_item.isra.39+0x6b2/0x6e0 btrfs_balance+0x72d/0x18d0 btrfs_ioctl_balance+0x3de/0x4c0 btrfs_ioctl+0x30ab/0x44a0 ksys_ioctl+0xa1/0xe0 __x64_sys_ioctl+0x43/0x50 do_syscall_64+0x77/0x2c0 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&delayed_node->mutex){+.+.}: __lock_acquire+0x197e/0x2550 lock_acquire+0x103/0x220 __mutex_lock+0x13d/0xce0 mutex_lock_nested+0x1b/0x20 __btrfs_release_delayed_node+0x7c/0x5b0 btrfs_remove_delayed_node+0x49/0x50 btrfs_evict_inode+0x6fc/0x900 evict+0x19a/0x2c0 dispose_list+0xa0/0xe0 prune_icache_sb+0xbd/0xf0 super_cache_scan+0x1b5/0x250 do_shrink_slab+0x1f6/0x530 shrink_slab+0x32e/0x410 shrink_node+0x2a5/0xba0 balance_pgdat+0x4bd/0x8a0 kswapd+0x35a/0x800 kthread+0x1e9/0x210 ret_from_fork+0x3a/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&delayed_node->mutex); lock(fs_reclaim); lock(&delayed_node->mutex); *** DEADLOCK *** 3 locks held by kswapd0/1133: #0: ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30 #1: ffffffff8fc380d8 (shrinker_rwsem){++++}, at: shrink_slab+0x1e8/0x410 #2: ffff8881e0e6c0e8 (&type->s_umount_key#42){++++}, at: trylock_super+0x1b/0x70 stack backtrace: CPU: 2 PID: 1133 Comm: kswapd0 Not tainted 5.6.0-c6f0579d496a+ #53 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack+0xc1/0x11a print_circular_bug.isra.38.cold.57+0x145/0x14a check_noncircular+0x2a9/0x2f0 ? print_circular_bug.isra.38+0x130/0x130 ? stack_trace_consume_entry+0x90/0x90 ? save_trace+0x3cc/0x420 __lock_acquire+0x197e/0x2550 ? btrfs_inode_clear_file_extent_range+0x9b/0xb0 ? register_lock_class+0x960/0x960 lock_acquire+0x103/0x220 ? __btrfs_release_delayed_node+0x7c/0x5b0 __mutex_lock+0x13d/0xce0 ? __btrfs_release_delayed_node+0x7c/0x5b0 ? __asan_loadN+0xf/0x20 ? pvclock_clocksource_read+0xeb/0x190 ? __btrfs_release_delayed_node+0x7c/0x5b0 ? mutex_lock_io_nested+0xc20/0xc20 ? __kasan_check_read+0x11/0x20 ? check_chain_key+0x1e6/0x2e0 mutex_lock_nested+0x1b/0x20 ? mutex_lock_nested+0x1b/0x20 __btrfs_release_delayed_node+0x7c/0x5b0 btrfs_remove_delayed_node+0x49/0x50 btrfs_evict_inode+0x6fc/0x900 ? btrfs_setattr+0x840/0x840 ? do_raw_spin_unlock+0xa8/0x140 evict+0x19a/0x2c0 dispose_list+0xa0/0xe0 prune_icache_sb+0xbd/0xf0 ? invalidate_inodes+0x310/0x310 super_cache_scan+0x1b5/0x250 do_shrink_slab+0x1f6/0x530 shrink_slab+0x32e/0x410 ? do_shrink_slab+0x530/0x530 ? do_shrink_slab+0x530/0x530 ? __kasan_check_read+0x11/0x20 ? mem_cgroup_protected+0x13d/0x260 shrink_node+0x2a5/0xba0 balance_pgdat+0x4bd/0x8a0 ? mem_cgroup_shrink_node+0x490/0x490 ? _raw_spin_unlock_irq+0x27/0x40 ? finish_task_switch+0xce/0x390 ? rcu_read_lock_bh_held+0xb0/0xb0 kswapd+0x35a/0x800 ? _raw_spin_unlock_irqrestore+0x4c/0x60 ? balance_pgdat+0x8a0/0x8a0 ? finish_wait+0x110/0x110 ? __kasan_check_read+0x11/0x20 ? __kthread_parkme+0xc6/0xe0 ? balance_pgdat+0x8a0/0x8a0 kthread+0x1e9/0x210 ? kthread_create_worker_on_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x50 This is because we hold that delayed node's mutex while doing tree operations. Fix this by just wrapping the searches in nofs. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>

A lockdep circular locking dependency report was seen when running a keyutils test: [12537.027242] ====================================================== [12537.059309] WARNING: possible circular locking dependency detected [12537.088148] 4.18.0-147.7.1.el8_1.x86_64+debug #1 Tainted: G OE --------- - - [12537.125253] ------------------------------------------------------ [12537.153189] keyctl/25598 is trying to acquire lock: [12537.175087] 000000007c39f96c (&mm->mmap_sem){++++}, at: __might_fault+0xc4/0x1b0 [12537.208365] [12537.208365] but task is already holding lock: [12537.234507] 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220 [12537.270476] [12537.270476] which lock already depends on the new lock. [12537.270476] [12537.307209] [12537.307209] the existing dependency chain (in reverse order) is: [12537.340754] [12537.340754] -> #3 (&type->lock_class){++++}: [12537.367434] down_write+0x4d/0x110 [12537.385202] __key_link_begin+0x87/0x280 [12537.405232] request_key_and_link+0x483/0xf70 [12537.427221] request_key+0x3c/0x80 [12537.444839] dns_query+0x1db/0x5a5 [dns_resolver] [12537.468445] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs] [12537.496731] cifs_reconnect+0xe04/0x2500 [cifs] [12537.519418] cifs_readv_from_socket+0x461/0x690 [cifs] [12537.546263] cifs_read_from_socket+0xa0/0xe0 [cifs] [12537.573551] cifs_demultiplex_thread+0x311/0x2db0 [cifs] [12537.601045] kthread+0x30c/0x3d0 [12537.617906] ret_from_fork+0x3a/0x50 [12537.636225] [12537.636225] -> #2 (root_key_user.cons_lock){+.+.}: [12537.664525] __mutex_lock+0x105/0x11f0 [12537.683734] request_key_and_link+0x35a/0xf70 [12537.705640] request_key+0x3c/0x80 [12537.723304] dns_query+0x1db/0x5a5 [dns_resolver] [12537.746773] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs] [12537.775607] cifs_reconnect+0xe04/0x2500 [cifs] [12537.798322] cifs_readv_from_socket+0x461/0x690 [cifs] [12537.823369] cifs_read_from_socket+0xa0/0xe0 [cifs] [12537.847262] cifs_demultiplex_thread+0x311/0x2db0 [cifs] [12537.873477] kthread+0x30c/0x3d0 [12537.890281] ret_from_fork+0x3a/0x50 [12537.908649] [12537.908649] -> #1 (&tcp_ses->srv_mutex){+.+.}: [12537.935225] __mutex_lock+0x105/0x11f0 [12537.954450] cifs_call_async+0x102/0x7f0 [cifs] [12537.977250] smb2_async_readv+0x6c3/0xc90 [cifs] [12538.000659] cifs_readpages+0x120a/0x1e50 [cifs] [12538.023920] read_pages+0xf5/0x560 [12538.041583] __do_page_cache_readahead+0x41d/0x4b0 [12538.067047] ondemand_readahead+0x44c/0xc10 [12538.092069] filemap_fault+0xec1/0x1830 [12538.111637] __do_fault+0x82/0x260 [12538.129216] do_fault+0x419/0xfb0 [12538.146390] __handle_mm_fault+0x862/0xdf0 [12538.167408] handle_mm_fault+0x154/0x550 [12538.187401] __do_page_fault+0x42f/0xa60 [12538.207395] do_page_fault+0x38/0x5e0 [12538.225777] page_fault+0x1e/0x30 [12538.243010] [12538.243010] -> #0 (&mm->mmap_sem){++++}: [12538.267875] lock_acquire+0x14c/0x420 [12538.286848] __might_fault+0x119/0x1b0 [12538.306006] keyring_read_iterator+0x7e/0x170 [12538.327936] assoc_array_subtree_iterate+0x97/0x280 [12538.352154] keyring_read+0xe9/0x110 [12538.370558] keyctl_read_key+0x1b9/0x220 [12538.391470] do_syscall_64+0xa5/0x4b0 [12538.410511] entry_SYSCALL_64_after_hwframe+0x6a/0xdf [12538.435535] [12538.435535] other info that might help us debug this: [12538.435535] [12538.472829] Chain exists of: [12538.472829] &mm->mmap_sem --> root_key_user.cons_lock --> &type->lock_class [12538.472829] [12538.524820] Possible unsafe locking scenario: [12538.524820] [12538.551431] CPU0 CPU1 [12538.572654] ---- ---- [12538.595865] lock(&type->lock_class); [12538.613737] lock(root_key_user.cons_lock); [12538.644234] lock(&type->lock_class); [12538.672410] lock(&mm->mmap_sem); [12538.687758] [12538.687758] *** DEADLOCK *** [12538.687758] [12538.714455] 1 lock held by keyctl/25598: [12538.732097] #0: 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220 [12538.770573] [12538.770573] stack backtrace: [12538.790136] CPU: 2 PID: 25598 Comm: keyctl Kdump: loaded Tainted: G [12538.844855] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 12/27/2015 [12538.881963] Call Trace: [12538.892897] dump_stack+0x9a/0xf0 [12538.907908] print_circular_bug.isra.25.cold.50+0x1bc/0x279 [12538.932891] ? save_trace+0xd6/0x250 [12538.948979] check_prev_add.constprop.32+0xc36/0x14f0 [12538.971643] ? keyring_compare_object+0x104/0x190 [12538.992738] ? check_usage+0x550/0x550 [12539.009845] ? sched_clock+0x5/0x10 [12539.025484] ? sched_clock_cpu+0x18/0x1e0 [12539.043555] __lock_acquire+0x1f12/0x38d0 [12539.061551] ? trace_hardirqs_on+0x10/0x10 [12539.080554] lock_acquire+0x14c/0x420 [12539.100330] ? __might_fault+0xc4/0x1b0 [12539.119079] __might_fault+0x119/0x1b0 [12539.135869] ? __might_fault+0xc4/0x1b0 [12539.153234] keyring_read_iterator+0x7e/0x170 [12539.172787] ? keyring_read+0x110/0x110 [12539.190059] assoc_array_subtree_iterate+0x97/0x280 [12539.211526] keyring_read+0xe9/0x110 [12539.227561] ? keyring_gc_check_iterator+0xc0/0xc0 [12539.249076] keyctl_read_key+0x1b9/0x220 [12539.266660] do_syscall_64+0xa5/0x4b0 [12539.283091] entry_SYSCALL_64_after_hwframe+0x6a/0xdf One way to prevent this deadlock scenario from happening is to not allow writing to userspace while holding the key semaphore. Instead, an internal buffer is allocated for getting the keys out from the read method first before copying them out to userspace without holding the lock. That requires taking out the __user modifier from all the relevant read methods as well as additional changes to not use any userspace write helpers. That is, 1) The put_user() call is replaced by a direct copy. 2) The copy_to_user() call is replaced by memcpy(). 3) All the fault handling code is removed. Compiling on a x86-64 system, the size of the rxrpc_read() function is reduced from 3795 bytes to 2384 bytes with this patch. Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com>

On some EFI systems, the video BIOS is provided by the EFI firmware. The boot stub code stores the physical address of the ROM image in pdev->rom. Currently we attempt to access this pointer using phys_to_virt(), which doesn't work with CONFIG_HIGHMEM. On these systems, attempting to load the radeon module on a x86_32 kernel can result in the following: BUG: unable to handle page fault for address: 3e8ed03c #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page *pde = 00000000 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 317 Comm: systemd-udevd Not tainted 5.6.0-rc3-next-20200228 #2 Hardware name: Apple Computer, Inc. MacPro1,1/Mac-F4208DC8, BIOS MP11.88Z.005C.B08.0707021221 07/02/07 EIP: radeon_get_bios+0x5ed/0xe50 [radeon] Code: 00 00 84 c0 0f 85 12 fd ff ff c7 87 64 01 00 00 00 00 00 00 8b 47 08 8b 55 b0 e8 1e 83 e1 d6 85 c0 74 1a 8b 55 c0 85 d2 74 13 <80> 38 55 75 0e 80 78 01 aa 0f 84 a4 03 00 00 8d 74 26 00 68 dc 06 EAX: 3e8ed03c EBX: 00000000 ECX: 3e8ed03c EDX: 00010000 ESI: 00040000 EDI: eec04000 EBP: eef3fc60 ESP: eef3fbe0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010206 CR0: 80050033 CR2: 3e8ed03c CR3: 2ec77000 CR4: 000006d0 Call Trace: r520_init+0x26/0x240 [radeon] radeon_device_init+0x533/0xa50 [radeon] radeon_driver_load_kms+0x80/0x220 [radeon] drm_dev_register+0xa7/0x180 [drm] radeon_pci_probe+0x10f/0x1a0 [radeon] pci_device_probe+0xd4/0x140 Fix the issue by updating all drivers which can access a platform provided ROM. Instead of calling the helper function pci_platform_rom() which uses phys_to_virt(), call ioremap() directly on the pdev->rom. radeon_read_platform_bios() previously directly accessed an __iomem pointer. Avoid this by calling memcpy_fromio() instead of kmemdup(). pci_platform_rom() now has no remaining callers, so remove it. Link: https://lore.kernel.org/r/20200319021623.5426-1-mikel@mikelr.com Signed-off-by: Mikel Rychliski <mikel@mikelr.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alex Deucher <alexander.deucher@amd.com>

Patch series "mm: memcontrol: recursive memory.low protection", v3. The current memory.low (and memory.min) semantics require protection to be assigned to a cgroup in an untinterrupted chain from the top-level cgroup all the way to the leaf. In practice, we want to protect entire cgroup subtrees from each other (system management software vs. workload), but we would like the VM to balance memory optimally *within* each subtree, without having to make explicit weight allocations among individual components. The current semantics make that impossible. They also introduce unmanageable complexity into more advanced resource trees. For example: host root `- system.slice `- rpm upgrades `- logging `- workload.slice `- a container `- system.slice `- workload.slice `- job A `- component 1 `- component 2 `- job B At a host-level perspective, we would like to protect the outer workload.slice subtree as a whole from rpm upgrades, logging etc. But for that to be effective, right now we'd have to propagate it down through the container, the inner workload.slice, into the job cgroup and ultimately the component cgroups where memory is actually, physically allocated. This may cross several tree delegation points and namespace boundaries, which make such a setup near impossible. CPU and IO on the other hand are already distributed recursively. The user would simply configure allowances at the host level, and they would apply to the entire subtree without any downward propagation. To enable the above-mentioned usecases and bring memory in line with other resource controllers, this patch series extends memory.low/min such that settings apply recursively to the entire subtree. Users can still assign explicit shares in subgroups, but if they don't, any ancestral protection will be distributed such that children compete freely amongst each other - as if no memory control were enabled inside the subtree - but enjoy protection from neighboring trees. In the above example, the user would then be able to configure shares of CPU, IO and memory at the host level to comprehensively protect and isolate the workload.slice as a whole from system.slice activity. Patch #1 fixes an existing bug that can give a cgroup tree more protection than it should receive as per ancestor configuration. Patch #2 simplifies and documents the existing code to make it easier to reason about the changes in the next patch. Patch #3 finally implements recursive memory protection semantics. Because of a risk of regressing legacy setups, the new semantics are hidden behind a cgroup2 mount option, 'memory_recursiveprot'. More details in patch #3. This patch (of 3): When memory.low is overcommitted - i.e. the children claim more protection than their shared ancestor grants them - the allowance is distributed in proportion to how much each sibling uses their own declared protection: low_usage = min(memory.low, memory.current) elow = parent_elow * (low_usage / siblings_low_usage) However, siblings_low_usage is not the sum of all low_usages. It sums up the usages of *only those cgroups that are within their memory.low* That means that low_usage can be *bigger* than siblings_low_usage, and consequently the total protection afforded to the children can be bigger than what the ancestor grants the subtree. Consider three groups where two are in excess of their protection: A/memory.low = 10G A/A1/memory.low = 10G, memory.current = 20G A/A2/memory.low = 10G, memory.current = 20G A/A3/memory.low = 10G, memory.current = 8G siblings_low_usage = 8G (only A3 contributes) A1/elow = parent_elow(10G) * low_usage(10G) / siblings_low_usage(8G) = 12.5G -> 10G A2/elow = parent_elow(10G) * low_usage(10G) / siblings_low_usage(8G) = 12.5G -> 10G A3/elow = parent_elow(10G) * low_usage(8G) / siblings_low_usage(8G) = 10.0G (the 12.5G are capped to the explicit memory.low setting of 10G) With that, the sum of all awarded protection below A is 30G, when A only grants 10G for the entire subtree. What does this mean in practice? A1 and A2 would still be in excess of their 10G allowance and would be reclaimed, whereas A3 would not. As they eventually drop below their protection setting, they would be counted in siblings_low_usage again and the error would right itself. When reclaim was applied in a binary fashion (cgroup is reclaimed when it's above its protection, otherwise it's skipped) this would actually work out just fine. However, since 1bc63fb ("mm, memcg: make scan aggression always exclude protection"), reclaim pressure is scaled to how much a cgroup is above its protection. As a result this calculation error unduly skews pressure away from A1 and A2 toward the rest of the system. But why did we do it like this in the first place? The reasoning behind exempting groups in excess from siblings_low_usage was to go after them first during reclaim in an overcommitted subtree: A/memory.low = 2G, memory.current = 4G A/A1/memory.low = 3G, memory.current = 2G A/A2/memory.low = 1G, memory.current = 2G siblings_low_usage = 2G (only A1 contributes) A1/elow = parent_elow(2G) * low_usage(2G) / siblings_low_usage(2G) = 2G A2/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(2G) = 1G While the children combined are overcomitting A and are technically both at fault, A2 is actively declaring unprotected memory and we would like to reclaim that first. However, while this sounds like a noble goal on the face of it, it doesn't make much difference in actual memory distribution: Because A is overcommitted, reclaim will not stop once A2 gets pushed back to within its allowance; we'll have to reclaim A1 either way. The end result is still that protection is distributed proportionally, with A1 getting 3/4 (1.5G) and A2 getting 1/4 (0.5G) of A's allowance. [ If A weren't overcommitted, it wouldn't make a difference since each cgroup would just get the protection it declares: A/memory.low = 2G, memory.current = 3G A/A1/memory.low = 1G, memory.current = 1G A/A2/memory.low = 1G, memory.current = 2G With the current calculation: siblings_low_usage = 1G (only A1 contributes) A1/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(1G) = 2G -> 1G A2/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(1G) = 2G -> 1G Including excess groups in siblings_low_usage: siblings_low_usage = 2G A1/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(2G) = 1G -> 1G A2/elow = parent_elow(2G) * low_usage(1G) / siblings_low_usage(2G) = 1G -> 1G ] Simplify the calculation and fix the proportional reclaim bug by including excess cgroups in siblings_low_usage. After this patch, the effective memory.low distribution from the example above would be as follows: A/memory.low = 10G A/A1/memory.low = 10G, memory.current = 20G A/A2/memory.low = 10G, memory.current = 20G A/A3/memory.low = 10G, memory.current = 8G siblings_low_usage = 28G A1/elow = parent_elow(10G) * low_usage(10G) / siblings_low_usage(28G) = 3.5G A2/elow = parent_elow(10G) * low_usage(10G) / siblings_low_usage(28G) = 3.5G A3/elow = parent_elow(10G) * low_usage(8G) / siblings_low_usage(28G) = 2.8G Fixes: 1bc63fb ("mm, memcg: make scan aggression always exclude protection") Fixes: 2306715 ("mm: memory.low hierarchical behavior") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Chris Down <chris@chrisdown.name> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Michal Koutný <mkoutny@suse.com> Link: http://lkml.kernel.org/r/20200227195606.46212-2-hannes@cmpxchg.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Similar to commit 0266d81 ("acpi/processor: Prevent cpu hotplug deadlock") except this is for acpi_processor_ffh_cstate_probe(): "The problem is that the work is scheduled on the current CPU from the hotplug thread associated with that CPU. It's not required to invoke these functions via the workqueue because the hotplug thread runs on the target CPU already. Check whether current is a per cpu thread pinned on the target CPU and invoke the function directly to avoid the workqueue." WARNING: possible circular locking dependency detected ------------------------------------------------------ cpuhp/1/15 is trying to acquire lock: ffffc90003447a28 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: __flush_work+0x4c6/0x630 but task is already holding lock: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x3e/0xc0 irq_calc_affinity_vectors+0x5f/0x91 __pci_enable_msix_range+0x10f/0x9a0 pci_alloc_irq_vectors_affinity+0x13e/0x1f0 pci_alloc_irq_vectors_affinity at drivers/pci/msi.c:1208 pqi_ctrl_init+0x72f/0x1618 [smartpqi] pqi_pci_probe.cold.63+0x882/0x892 [smartpqi] local_pci_probe+0x7a/0xc0 work_for_cpu_fn+0x2e/0x50 process_one_work+0x57e/0xb90 worker_thread+0x363/0x5b0 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 -> #0 ((work_completion)(&wfc.work)){+.+.}-{0:0}: __lock_acquire+0x2244/0x32a0 lock_acquire+0x1a2/0x680 __flush_work+0x4e6/0x630 work_on_cpu+0x114/0x160 acpi_processor_ffh_cstate_probe+0x129/0x250 acpi_processor_evaluate_cst+0x4c8/0x580 acpi_processor_get_power_info+0x86/0x740 acpi_processor_hotplug+0xc3/0x140 acpi_soft_cpu_online+0x102/0x1d0 cpuhp_invoke_callback+0x197/0x1120 cpuhp_thread_fun+0x252/0x2f0 smpboot_thread_fn+0x255/0x440 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 other info that might help us debug this: Chain exists of: (work_completion)(&wfc.work) --> cpuhp_state-up --> cpuidle_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(cpuidle_lock); lock(cpuhp_state-up); lock(cpuidle_lock); lock((work_completion)(&wfc.work)); *** DEADLOCK *** 3 locks held by cpuhp/1/15: #0: ffffffffaf51ab10 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0 #1: ffffffffaf51ad40 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0 #2: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20 Call Trace: dump_stack+0xa0/0xea print_circular_bug.cold.52+0x147/0x14c check_noncircular+0x295/0x2d0 __lock_acquire+0x2244/0x32a0 lock_acquire+0x1a2/0x680 __flush_work+0x4e6/0x630 work_on_cpu+0x114/0x160 acpi_processor_ffh_cstate_probe+0x129/0x250 acpi_processor_evaluate_cst+0x4c8/0x580 acpi_processor_get_power_info+0x86/0x740 acpi_processor_hotplug+0xc3/0x140 acpi_soft_cpu_online+0x102/0x1d0 cpuhp_invoke_callback+0x197/0x1120 cpuhp_thread_fun+0x252/0x2f0 smpboot_thread_fn+0x255/0x440 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 Signed-off-by: Qian Cai <cai@lca.pw> Tested-by: Borislav Petkov <bp@suse.de> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Patch series "mm: Fix misuse of parent anon_vma in dup_mmap path". This patchset fixes the misuse of parenet anon_vma, which mainly caused by child vma's vm_next and vm_prev are left same as its parent after duplicate vma. Finally, code reached parent vma's neighbor by referring pointer of child vma and executed wrong logic. The first two patches fix relevant issues, and the third patch sets vm_next and vm_prev to NULL when duplicate vma to prevent potential misuse in future. Effects of the first bug is that causes rmap code to check both parent and child's page table, although a page couldn't be mapped by both parent and child, because child vma has WIPEONFORK so all pages mapped by child are 'new' and not relevant to parent. Effects of the second bug is that the relationship of anon_vma of parent and child are totallyconvoluted. It would cause 'son', 'grandson', ..., etc, to share 'parent' anon_vma, which disobey the design rule of reusing anon_vma (the rule to be followed is that reusing should among vma of same process, and vma should not gone through fork). So, both issues should cause unnecessary rmap walking and have unexpected complexity. These two issues would not be directly visible, I used debugging code to check the anon_vma pointers of parent and child when inspecting the suspicious implementation of issue #2, then find the problem. This patch (of 3): In dup_mmap(), anon_vma_prepare() is called for vma has VM_WIPEONFORK, and parameter 'tmp' (i.e., the new vma of child) has same ->vm_next and ->vm_prev as its parent vma. That allows anon_vma used by parent been mistakenly shared by child (find_mergeable_anon_vma() will do this reuse work). Besides this issue, call anon_vma_prepare() should be avoided because we don't copy page for this vma. Preparing anon_vma will be handled during fault. Fixes: d2cd9ed ("mm,fork: introduce MADV_WIPEONFORK") Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Link: http://lkml.kernel.org/r/1581150928-3214-2-git-send-email-lixinhai.lxh@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Ido Schimmel says: ==================== mlxsw: Two small changes Patch #1 increases the scale of supported IPv6 nexthops groups when each group has one nexthop and all are using the same nexthop device, but with a different gateway IP. Patch #2 adjusts a register definition in accordance with recent firmware changes. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Petr Machata says: ==================== Add selftests for pedit ex munge ip6 dsfield Patch #1 extends the existing generic forwarding selftests to cover pedit ex munge ip6 traffic_class as well. Patch #2 adds TDC test coverage. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says: ==================== mlxsw: Mirroring cleanups This patch set contains various cleanups in SPAN (mirroring) code noticed by Amit and I while working on future enhancements in this area. No functional changes intended. Tested by current mirroring selftests. Patches #1-#2 from Amit reduce nesting in a certain function and rename a callback to a more meaningful name. Patch #3 removes debug prints that have little value. Patch #4 converts a reference count to 'refcount_t' in order to catch over/under flows. Patch #5 replaces a zero-length array with flexible-array member in order to get a compiler warning in case the flexible array does not occur last in the structure. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

…git/netfilter/nf Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following batch contains two fixes from Florian Westphal: Patch #1 fixes a sk refcount leak in nft_socket on mismatch. Patch #2 fixes cgroupsv2 matching from containers due to incorrect level in subtree. netfilter pull request 24-09-12 * tag 'nf-24-09-12' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: nft_socket: make cgroupsv2 matching work with namespaces netfilter: nft_socket: fix sk refcount leaks ==================== Link: https://patch.msgid.link/20240911222520.3606-1-pablo@netfilter.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Ido Schimmel says: ==================== net: fib_rules: Add DSCP selector support Currently, the kernel rejects IPv4 FIB rules that try to match on the upper three DSCP bits: # ip -4 rule add tos 0x1c table 100 # ip -4 rule add tos 0x3c table 100 Error: Invalid tos. The reason for that is that historically users of the FIB lookup API only populated the lower three DSCP bits in the TOS field of the IPv4 flow key ('flowi4_tos'), which fits the TOS definition from the initial IPv4 specification (RFC 791). This is not very useful nowadays and instead some users want to be able to match on the six bits DSCP field, which replaced the TOS and IP precedence fields over 25 years ago (RFC 2474). In addition, the current behavior differs between IPv4 and IPv6 which does allow users to match on the entire DSCP field using the TOS selector. Recent patchsets made sure that callers of the FIB lookup API now populate the entire DSCP field in the IPv4 flow key. Therefore, it is now possible to extend FIB rules to match on DSCP. This is done by adding a new DSCP attribute which is implemented for both IPv4 and IPv6 to provide user space programs a consistent behavior between both address families. The behavior of the old TOS selector is unchanged and IPv4 FIB rules using it will only match on the lower three DSCP bits. The kernel will reject rules that try to use both selectors. Patch #1 adds the new DSCP attribute but rejects its usage. Patches #2-#3 implement IPv4 and IPv6 support. Patch #4 allows user space to use the new attribute. Patches #5-#6 add selftests. ==================== Link: https://patch.msgid.link/20240911093748.3662015-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Nelson Escobar says: ==================== enic: Report per queue stats Patch #1: Use a macro instead of static const variables for array sizes. I didn't want to add more static const variables in the next patch so clean up the existing ones first. Patch #2: Collect per queue statistics Patch #3: Report per queue stats in netdev qstats Patch #4: Report some per queue stats in ethtool # NETIF="eno6" tools/testing/selftests/drivers/net/stats.py KTAP version 1 1..5 ok 1 stats.check_pause # XFAIL pause not supported by the device ok 2 stats.check_fec # XFAIL FEC not supported by the device ok 3 stats.pkt_byte_sum ok 4 stats.qstat_by_ifindex ok 5 stats.check_down # tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \ --dump qstats-get --json '{"ifindex": "34"}' [{'ifindex': 34, 'rx-bytes': 66762680, 'rx-csum-unnecessary': 1009345, 'rx-hw-drop-overruns': 0, 'rx-hw-drops': 0, 'rx-packets': 1009673, 'tx-bytes': 137936674899, 'tx-csum-none': 125, 'tx-hw-gso-packets': 2408712, 'tx-needs-csum': 2431531, 'tx-packets': 15475466, 'tx-stop': 0, 'tx-wake': 0}] v2: https://lore.kernel.org/20240905010900.24152-1-neescoba@cisco.com v1: https://lore.kernel.org/20240823235401.29996-1-neescoba@cisco.com ==================== Link: https://patch.msgid.link/20240912005039.10797-1-neescoba@cisco.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

…git/netfilter/nf Pablo Neira Ayuso says: ==================== Netfilter fixes for net v2: with kdoc fixes per Paolo Abeni. The following patchset contains Netfilter fixes for net: Patch #1 and #2 handle an esoteric scenario: Given two tasks sending UDP packets to one another, two packets of the same flow in each direction handled by different CPUs that result in two conntrack objects in NEW state, where reply packet loses race. Then, patch #3 adds a testcase for this scenario. Series from Florian Westphal. 1) NAT engine can falsely detect a port collision if it happens to pick up a reply packet as NEW rather than ESTABLISHED. Add extra code to detect this and suppress port reallocation in this case. 2) To complete the clash resolution in the reply direction, extend conntrack logic to detect clashing conntrack in the reply direction to existing entry. 3) Adds a test case. Then, an assorted list of fixes follow: 4) Add a selftest for tproxy, from Antonio Ojea. 5) Guard ctnetlink_*_size() functions under #if defined(CONFIG_NETFILTER_NETLINK_GLUE_CT) || defined(CONFIG_NF_CONNTRACK_EVENTS) From Andy Shevchenko. 6) Use -m socket --transparent in iptables tproxy documentation. From XIE Zhibang. 7) Call kfree_rcu() when releasing flowtable hooks to address race with netlink dump path, from Phil Sutter. 8) Fix compilation warning in nf_reject with CONFIG_BRIDGE_NETFILTER=n. From Simon Horman. 9) Guard ctnetlink_label_size() under CONFIG_NF_CONNTRACK_EVENTS which is its only user, to address a compilation warning. From Simon Horman. 10) Use rcu-protected list iteration over basechain hooks from netlink dump path. 11) Fix memcg for nf_tables, use GFP_KERNEL_ACCOUNT is not complete. 12) Remove old nfqueue conntrack clash resolution. Instead trying to use same destination address consistently which requires double DNAT, use the existing clash resolution which allows clashing packets go through with different destination. Antonio Ojea originally reported an issue from the postrouting chain, I proposed a fix: https://lore.kernel.org/netfilter-devel/ZuwSwAqKgCB2a51-@calendula/T/ which he reported it did not work for him. 13) Adds a selftest for patch 12. 14) Fixes ipvs.sh selftest. netfilter pull request 24-09-26 * tag 'nf-24-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: selftests: netfilter: Avoid hanging ipvs.sh kselftest: add test for nfqueue induced conntrack race netfilter: nfnetlink_queue: remove old clash resolution logic netfilter: nf_tables: missing objects with no memcg accounting netfilter: nf_tables: use rcu chain hook list iterator from netlink dump path netfilter: ctnetlink: compile ctnetlink_label_size with CONFIG_NF_CONNTRACK_EVENTS netfilter: nf_reject: Fix build warning when CONFIG_BRIDGE_NETFILTER=n netfilter: nf_tables: Keep deleted flowtable hooks until after RCU docs: tproxy: ignore non-transparent sockets in iptables netfilter: ctnetlink: Guard possible unused functions selftests: netfilter: nft_tproxy.sh: add tcp tests selftests: netfilter: add reverse-clash resolution test case netfilter: conntrack: add clash resolution for reverse collisions netfilter: nf_nat: don't try nat source port reallocation for reverse dir clash ==================== Link: https://patch.msgid.link/20240926110717.102194-1-pablo@netfilter.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Hou Tao says: ==================== The tiny patch set aims to fix two problems found during the development of supporting dynptr key in hash table. Patch #1 fixes the missed btf_record_free() when map creation fails and patch #2 fixes the missed kfree() when there is no special field in the passed btf. ==================== Link: https://lore.kernel.org/r/20240912012845.3458483-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Syzkaller reported a lockdep splat: ============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted -------------------------------------------- syz-executor364/5113 is trying to acquire lock: ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 but task is already holding lock: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-slock-AF_INET); lock(k-slock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor364/5113: #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806 #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228 #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232 #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 stack backtrace: CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279 subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874 tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853 tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 </IRQ> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235 ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline] tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729 tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x214/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733 mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04fb13a6b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9 RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004 RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300 </TASK> As noted by Cong Wang, the splat is false positive, but the code path leading to the report is an unexpected one: a client is attempting an MPC handshake towards the in-kernel listener created by the in-kernel PM for a port based signal endpoint. Such connection will be never accepted; many of them can make the listener queue full and preventing the creation of MPJ subflow via such listener - its intended role. Explicitly detect this scenario at initial-syn time and drop the incoming MPC request. Fixes: 1729cf1 ("mptcp: create the listening socket for new port") Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e Signed-off-by: Paolo Abeni <pabeni@redhat.com> Message-ID: <833cae5982ac5d5b3236845c6db4315e634f5705.1727974826.git.pabeni@redhat.com>

The following calculation used in coalesced_mmio_has_room() to check whether the ring buffer is full is wrong and results in premature exits if the start of the valid entries is in the first half of the ring buffer. avail = (ring->first - last - 1) % KVM_COALESCED_MMIO_MAX; if (avail == 0) /* full */ Because negative values are handled using two's complement, and KVM computes the result as an unsigned value, the above will get a false positive if "first < last" and the ring is half-full. The above might have worked as expected in python for example: >>> (-86) % 170 84 However it doesn't work the same way in C. printf("avail: %d\n", (-86) % 170); printf("avail: %u\n", (-86) % 170); printf("avail: %u\n", (-86u) % 170u); Using gcc-11 these print: avail: -86 avail: 4294967210 avail: 0 For illustration purposes, given a 4-bit integer and a ring size of 0xA (unsigned), 0xA == 0x1010 == -6, and thus (-6u % 0xA) == 0. Fix the calculation and allow all but one entries in the buffer to be used as originally intended. Note, KVM's behavior is self-healing to some extent, as KVM will allow the entire buffer to be used if ring->first is beyond the halfway point. In other words, in the unlikely scenario that a use case benefits from being able to coalesce more than 86 entries at once, KVM will still provide such behavior, sometimes. Note #2, the % operator in C is not the modulo operator but the remainder operator. Modulo and remainder operators differ with respect to negative values. But, the relevant values in KVM are all unsigned, so it's a moot point in this case anyway. Note #3, this is almost a pure revert of the buggy commit, plus a READ_ONCE() to provide additional safety. Thue buggy commit justified the change with "it paves the way for making this function lockless", but it's not at all clear what was intended, nor is there any evidence that the buggy code was somehow safer. (a) the fields in question were already accessed locklessly, from the perspective that they could be modified by userspace at any time, and (b) the lock guarding the ring itself was changed, but never dropped, i.e. whatever lockless scheme (SRCU?) was planned never landed. Fixes: 105f8d4 ("KVM: Calculate available entries in coalesced mmio ring") Signed-off-by: Ilias Stamatis <ilstam@amazon.com> Reviewed-by: Paul Durrant <paul@xen.org> Link: https://lore.kernel.org/r/20240718193543.624039-2-ilstam@amazon.com [sean: rework changelog to clarify behavior, call out weirdness of buggy commit] Signed-off-by: Sean Christopherson <seanjc@google.com>

Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock on x86 due to a chain of locks and SRCU synchronizations. Translating the below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the fairness of r/w semaphores). CPU0 CPU1 CPU2 1 lock(&kvm->slots_lock); 2 lock(&vcpu->mutex); 3 lock(&kvm->srcu); 4 lock(cpu_hotplug_lock); 5 lock(kvm_lock); 6 lock(&kvm->slots_lock); 7 lock(cpu_hotplug_lock); 8 sync(&kvm->srcu); Note, there are likely more potential deadlocks in KVM x86, e.g. the same pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with __kvmclock_cpufreq_notifier(): cpuhp_cpufreq_online() | -> cpufreq_online() | -> cpufreq_gov_performance_limits() | -> __cpufreq_driver_target() | -> __target_index() | -> cpufreq_freq_transition_begin() | -> cpufreq_notify_transition() | -> ... __kvmclock_cpufreq_notifier() But, actually triggering such deadlocks is beyond rare due to the combination of dependencies and timings involved. E.g. the cpufreq notifier is only used on older CPUs without a constant TSC, mucking with the NX hugepage mitigation while VMs are running is very uncommon, and doing so while also onlining/offlining a CPU (necessary to generate contention on cpu_hotplug_lock) would be even more unusual. The most robust solution to the general cpu_hotplug_lock issue is likely to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq notifier doesn't to take kvm_lock. For now, settle for fixing the most blatant deadlock, as switching to an RCU-protected list is a much more involved change, but add a comment in locking.rst to call out that care needs to be taken when walking holding kvm_lock and walking vm_list. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-smp--c257535a0c9d-pip #330 Tainted: G S O ------------------------------------------------------ tee/35048 is trying to acquire lock: ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm] but task is already holding lock: ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (kvm_lock){+.+.}-{3:3}: __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 kvm_dev_ioctl+0x4fb/0xe50 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #2 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x2e/0xb0 static_key_slow_inc+0x16/0x30 kvm_lapic_set_base+0x6a/0x1c0 [kvm] kvm_set_apic_base+0x8f/0xe0 [kvm] kvm_set_msr_common+0x9ae/0xf80 [kvm] vmx_set_msr+0xa54/0xbe0 [kvm_intel] __kvm_set_msr+0xb6/0x1a0 [kvm] kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm] kvm_vcpu_ioctl+0x485/0x5b0 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&kvm->srcu){.+.+}-{0:0}: __synchronize_srcu+0x44/0x1a0 synchronize_srcu_expedited+0x21/0x30 kvm_swap_active_memslots+0x110/0x1c0 [kvm] kvm_set_memslot+0x360/0x620 [kvm] __kvm_set_memory_region+0x27b/0x300 [kvm] kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm] kvm_vm_ioctl+0x295/0x650 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&kvm->slots_lock){+.+.}-{3:3}: __lock_acquire+0x15ef/0x2e30 lock_acquire+0xe0/0x260 __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 set_nx_huge_pages+0x179/0x1e0 [kvm] param_attr_store+0x93/0x100 module_attr_store+0x22/0x40 sysfs_kf_write+0x81/0xb0 kernfs_fop_write_iter+0x133/0x1d0 vfs_write+0x28d/0x380 ksys_write+0x70/0xe0 __x64_sys_write+0x1f/0x30 x64_sys_call+0x281b/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Cc: Chao Gao <chao.gao@intel.com> Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock") Cc: stable@vger.kernel.org Reviewed-by: Kai Huang <kai.huang@intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240830043600.127750-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Fix a kernel panic in the br_netfilter module when sending untagged traffic via a VxLAN device. This happens during the check for fragmentation in br_nf_dev_queue_xmit. It is dependent on: 1) the br_netfilter module being loaded; 2) net.bridge.bridge-nf-call-iptables set to 1; 3) a bridge with a VxLAN (single-vxlan-device) netdevice as a bridge port; 4) untagged frames with size higher than the VxLAN MTU forwarded/flooded When forwarding the untagged packet to the VxLAN bridge port, before the netfilter hooks are called, br_handle_egress_vlan_tunnel is called and changes the skb_dst to the tunnel dst. The tunnel_dst is a metadata type of dst, i.e., skb_valid_dst(skb) is false, and metadata->dst.dev is NULL. Then in the br_netfilter hooks, in br_nf_dev_queue_xmit, there's a check for frames that needs to be fragmented: frames with higher MTU than the VxLAN device end up calling br_nf_ip_fragment, which in turns call ip_skb_dst_mtu. The ip_dst_mtu tries to use the skb_dst(skb) as if it was a valid dst with valid dst->dev, thus the crash. This case was never supported in the first place, so drop the packet instead. PING 10.0.0.2 (10.0.0.2) from 0.0.0.0 h1-eth0: 2000(2028) bytes of data. [ 176.291791] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000110 [ 176.292101] Mem abort info: [ 176.292184] ESR = 0x0000000096000004 [ 176.292322] EC = 0x25: DABT (current EL), IL = 32 bits [ 176.292530] SET = 0, FnV = 0 [ 176.292709] EA = 0, S1PTW = 0 [ 176.292862] FSC = 0x04: level 0 translation fault [ 176.293013] Data abort info: [ 176.293104] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 176.293488] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 176.293787] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 176.293995] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000043ef5000 [ 176.294166] [0000000000000110] pgd=0000000000000000, p4d=0000000000000000 [ 176.294827] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 176.295252] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel veth br_netfilter bridge stp llc ipv6 crct10dif_ce [ 176.295923] CPU: 0 PID: 188 Comm: ping Not tainted 6.8.0-rc3-g5b3fbd61b9d1 #2 [ 176.296314] Hardware name: linux,dummy-virt (DT) [ 176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter] [ 176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter] [ 176.297636] sp : ffff800080003630 [ 176.297743] x29: ffff800080003630 x28: 0000000000000008 x27: ffff6828c49ad9f8 [ 176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24: 00000000000003e8 [ 176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21: ffff6828c3b16d28 [ 176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18: 0000000000000014 [ 176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15: 0000000095744632 [ 176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12: ffffb7e137926a70 [ 176.299574] x11: 0000000000000001 x10: ffff6828c3f1c898 x9 : 0000000000000000 [ 176.300049] x8 : ffff6828c49bf070 x7 : 0008460f18d5f20e x6 : f20e0100bebafeca [ 176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 : 0000000000000000 [ 176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 : ffff6828c7f918f0 [ 176.300889] Call trace: [ 176.301123] br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter] [ 176.301411] br_nf_post_routing+0x2a8/0x3e4 [br_netfilter] [ 176.301703] nf_hook_slow+0x48/0x124 [ 176.302060] br_forward_finish+0xc8/0xe8 [bridge] [ 176.302371] br_nf_hook_thresh+0x124/0x134 [br_netfilter] [ 176.302605] br_nf_forward_finish+0x118/0x22c [br_netfilter] [ 176.302824] br_nf_forward_ip.part.0+0x264/0x290 [br_netfilter] [ 176.303136] br_nf_forward+0x2b8/0x4e0 [br_netfilter] [ 176.303359] nf_hook_slow+0x48/0x124 [ 176.303803] __br_forward+0xc4/0x194 [bridge] [ 176.304013] br_flood+0xd4/0x168 [bridge] [ 176.304300] br_handle_frame_finish+0x1d4/0x5c4 [bridge] [ 176.304536] br_nf_hook_thresh+0x124/0x134 [br_netfilter] [ 176.304978] br_nf_pre_routing_finish+0x29c/0x494 [br_netfilter] [ 176.305188] br_nf_pre_routing+0x250/0x524 [br_netfilter] [ 176.305428] br_handle_frame+0x244/0x3cc [bridge] [ 176.305695] __netif_receive_skb_core.constprop.0+0x33c/0xecc [ 176.306080] __netif_receive_skb_one_core+0x40/0x8c [ 176.306197] __netif_receive_skb+0x18/0x64 [ 176.306369] process_backlog+0x80/0x124 [ 176.306540] __napi_poll+0x38/0x17c [ 176.306636] net_rx_action+0x124/0x26c [ 176.306758] __do_softirq+0x100/0x26c [ 176.307051] ____do_softirq+0x10/0x1c [ 176.307162] call_on_irq_stack+0x24/0x4c [ 176.307289] do_softirq_own_stack+0x1c/0x2c [ 176.307396] do_softirq+0x54/0x6c [ 176.307485] __local_bh_enable_ip+0x8c/0x98 [ 176.307637] __dev_queue_xmit+0x22c/0xd28 [ 176.307775] neigh_resolve_output+0xf4/0x1a0 [ 176.308018] ip_finish_output2+0x1c8/0x628 [ 176.308137] ip_do_fragment+0x5b4/0x658 [ 176.308279] ip_fragment.constprop.0+0x48/0xec [ 176.308420] __ip_finish_output+0xa4/0x254 [ 176.308593] ip_finish_output+0x34/0x130 [ 176.308814] ip_output+0x6c/0x108 [ 176.308929] ip_send_skb+0x50/0xf0 [ 176.309095] ip_push_pending_frames+0x30/0x54 [ 176.309254] raw_sendmsg+0x758/0xaec [ 176.309568] inet_sendmsg+0x44/0x70 [ 176.309667] __sys_sendto+0x110/0x178 [ 176.309758] __arm64_sys_sendto+0x28/0x38 [ 176.309918] invoke_syscall+0x48/0x110 [ 176.310211] el0_svc_common.constprop.0+0x40/0xe0 [ 176.310353] do_el0_svc+0x1c/0x28 [ 176.310434] el0_svc+0x34/0xb4 [ 176.310551] el0t_64_sync_handler+0x120/0x12c [ 176.310690] el0t_64_sync+0x190/0x194 [ 176.311066] Code: f9402e61 79402aa2 927ff821 f9400023 (f9408860) [ 176.315743] ---[ end trace 0000000000000000 ]--- [ 176.316060] Kernel panic - not syncing: Oops: Fatal exception in interrupt [ 176.316371] Kernel Offset: 0x37e0e3000000 from 0xffff800080000000 [ 176.316564] PHYS_OFFSET: 0xffff97d780000000 [ 176.316782] CPU features: 0x0,88000203,3c020000,0100421b [ 176.317210] Memory Limit: none [ 176.317527] ---[ end Kernel panic - not syncing: Oops: Fatal Exception in interrupt ]---\ Fixes: 11538d0 ("bridge: vlan dst_metadata hooks in ingress and egress paths") Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Andy Roulin <aroulin@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20241001154400.22787-2-aroulin@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Andy Roulin says: ==================== netfilter: br_netfilter: fix panic with metadata_dst skb There's a kernel panic possible in the br_netfilter module when sending untagged traffic via a VxLAN device. Traceback is included below. This happens during the check for fragmentation in br_nf_dev_queue_xmit if the MTU on the VxLAN device is not big enough. It is dependent on: 1) the br_netfilter module being loaded; 2) net.bridge.bridge-nf-call-iptables set to 1; 3) a bridge with a VxLAN (single-vxlan-device) netdevice as a bridge port; 4) untagged frames with size higher than the VxLAN MTU forwarded/flooded This case was never supported in the first place, so the first patch drops such packets. A regression selftest is added as part of the second patch. PING 10.0.0.2 (10.0.0.2) from 0.0.0.0 h1-eth0: 2000(2028) bytes of data. [ 176.291791] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000110 [ 176.292101] Mem abort info: [ 176.292184] ESR = 0x0000000096000004 [ 176.292322] EC = 0x25: DABT (current EL), IL = 32 bits [ 176.292530] SET = 0, FnV = 0 [ 176.292709] EA = 0, S1PTW = 0 [ 176.292862] FSC = 0x04: level 0 translation fault [ 176.293013] Data abort info: [ 176.293104] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 176.293488] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 176.293787] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 176.293995] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000043ef5000 [ 176.294166] [0000000000000110] pgd=0000000000000000, p4d=0000000000000000 [ 176.294827] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 176.295252] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel veth br_netfilter bridge stp llc ipv6 crct10dif_ce [ 176.295923] CPU: 0 PID: 188 Comm: ping Not tainted 6.8.0-rc3-g5b3fbd61b9d1 #2 [ 176.296314] Hardware name: linux,dummy-virt (DT) [ 176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter] [ 176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter] [ 176.297636] sp : ffff800080003630 [ 176.297743] x29: ffff800080003630 x28: 0000000000000008 x27: ffff6828c49ad9f8 [ 176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24: 00000000000003e8 [ 176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21: ffff6828c3b16d28 [ 176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18: 0000000000000014 [ 176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15: 0000000095744632 [ 176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12: ffffb7e137926a70 [ 176.299574] x11: 0000000000000001 x10: ffff6828c3f1c898 x9 : 0000000000000000 [ 176.300049] x8 : ffff6828c49bf070 x7 : 0008460f18d5f20e x6 : f20e0100bebafeca [ 176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 : 0000000000000000 [ 176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 : ffff6828c7f918f0 [ 176.300889] Call trace: [ 176.301123] br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter] [ 176.301411] br_nf_post_routing+0x2a8/0x3e4 [br_netfilter] [ 176.301703] nf_hook_slow+0x48/0x124 [ 176.302060] br_forward_finish+0xc8/0xe8 [bridge] [ 176.302371] br_nf_hook_thresh+0x124/0x134 [br_netfilter] [ 176.302605] br_nf_forward_finish+0x118/0x22c [br_netfilter] [ 176.302824] br_nf_forward_ip.part.0+0x264/0x290 [br_netfilter] [ 176.303136] br_nf_forward+0x2b8/0x4e0 [br_netfilter] [ 176.303359] nf_hook_slow+0x48/0x124 [ 176.303803] __br_forward+0xc4/0x194 [bridge] [ 176.304013] br_flood+0xd4/0x168 [bridge] [ 176.304300] br_handle_frame_finish+0x1d4/0x5c4 [bridge] [ 176.304536] br_nf_hook_thresh+0x124/0x134 [br_netfilter] [ 176.304978] br_nf_pre_routing_finish+0x29c/0x494 [br_netfilter] [ 176.305188] br_nf_pre_routing+0x250/0x524 [br_netfilter] [ 176.305428] br_handle_frame+0x244/0x3cc [bridge] [ 176.305695] __netif_receive_skb_core.constprop.0+0x33c/0xecc [ 176.306080] __netif_receive_skb_one_core+0x40/0x8c [ 176.306197] __netif_receive_skb+0x18/0x64 [ 176.306369] process_backlog+0x80/0x124 [ 176.306540] __napi_poll+0x38/0x17c [ 176.306636] net_rx_action+0x124/0x26c [ 176.306758] __do_softirq+0x100/0x26c [ 176.307051] ____do_softirq+0x10/0x1c [ 176.307162] call_on_irq_stack+0x24/0x4c [ 176.307289] do_softirq_own_stack+0x1c/0x2c [ 176.307396] do_softirq+0x54/0x6c [ 176.307485] __local_bh_enable_ip+0x8c/0x98 [ 176.307637] __dev_queue_xmit+0x22c/0xd28 [ 176.307775] neigh_resolve_output+0xf4/0x1a0 [ 176.308018] ip_finish_output2+0x1c8/0x628 [ 176.308137] ip_do_fragment+0x5b4/0x658 [ 176.308279] ip_fragment.constprop.0+0x48/0xec [ 176.308420] __ip_finish_output+0xa4/0x254 [ 176.308593] ip_finish_output+0x34/0x130 [ 176.308814] ip_output+0x6c/0x108 [ 176.308929] ip_send_skb+0x50/0xf0 [ 176.309095] ip_push_pending_frames+0x30/0x54 [ 176.309254] raw_sendmsg+0x758/0xaec [ 176.309568] inet_sendmsg+0x44/0x70 [ 176.309667] __sys_sendto+0x110/0x178 [ 176.309758] __arm64_sys_sendto+0x28/0x38 [ 176.309918] invoke_syscall+0x48/0x110 [ 176.310211] el0_svc_common.constprop.0+0x40/0xe0 [ 176.310353] do_el0_svc+0x1c/0x28 [ 176.310434] el0_svc+0x34/0xb4 [ 176.310551] el0t_64_sync_handler+0x120/0x12c [ 176.310690] el0t_64_sync+0x190/0x194 [ 176.311066] Code: f9402e61 79402aa2 927ff821 f9400023 (f9408860) [ 176.315743] ---[ end trace 0000000000000000 ]--- [ 176.316060] Kernel panic - not syncing: Oops: Fatal exception in interrupt [ 176.316371] Kernel Offset: 0x37e0e3000000 from 0xffff800080000000 [ 176.316564] PHYS_OFFSET: 0xffff97d780000000 [ 176.316782] CPU features: 0x0,88000203,3c020000,0100421b [ 176.317210] Memory Limit: none [ 176.317527] ---[ end Kernel panic - not syncing: Oops: Fatal Exception in interrupt ]---\ ==================== Link: https://patch.msgid.link/20241001154400.22787-1-aroulin@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Tariq Toukan says: ==================== net/mlx5: hw counters refactor This is a patchset re-post, see: https://lore.kernel.org/20240815054656.2210494-7-tariqt@nvidia.com In this patchset, Cosmin refactors hw counters and solves perf scaling issue. Series generated against: commit c824deb ("cxgb4: clip_tbl: Fix spelling mistake "wont" -> "won't"") HW counters are central to mlx5 driver operations. They are hardware objects created and used alongside most steering operations, and queried from a variety of places. Most counters are queried in bulk from a periodic task in fs_counters.c. Counter performance is important and as such, a variety of improvements have been done over the years. Currently, counters are allocated from pools, which are bulk allocated to amortize the cost of firmware commands. Counters are managed through an IDR, a doubly linked list and two atomic single linked lists. Adding/removing counters is a complex dance between user contexts requesting it and the mlx5_fc_stats_work task which does most of the work. Under high load (e.g. from connection tracking flow insertion/deletion), the counter code becomes a bottleneck, as seen on flame graphs. Whenever a counter is deleted, it gets added to a list and the wq task is scheduled to run immediately to actually delete it. This is done via mod_delayed_work which uses an internal spinlock. In some tests, waiting for this spinlock took up to 66% of all samples. This series refactors the counter code to use a more straight-forward approach, avoiding the mod_delayed_work problem and making the code easier to understand. For that: - patch #1 moves counters data structs to a more appropriate place. - patch #2 simplifies the bulk query allocation scheme by using vmalloc. - patch #3 replaces the IDR+3 lists with an xarray. This is the main patch of the series, solving the spinlock congestion issue. - patch #4 removes an unnecessary cacheline alignment causing a lot of memory to be wasted. - patches #5 and #6 are small cleanups enabled by the refactoring. ==================== Link: https://patch.msgid.link/20241001103709.58127-1-tariqt@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Syzkaller reported a lockdep splat: ============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted -------------------------------------------- syz-executor364/5113 is trying to acquire lock: ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 but task is already holding lock: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-slock-AF_INET); lock(k-slock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor364/5113: #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806 #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228 #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232 #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 stack backtrace: CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279 subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874 tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853 tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 </IRQ> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235 ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline] tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729 tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x214/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733 mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04fb13a6b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9 RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004 RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300 </TASK> As noted by Cong Wang, the splat is false positive, but the code path leading to the report is an unexpected one: a client is attempting an MPC handshake towards the in-kernel listener created by the in-kernel PM for a port based signal endpoint. Such connection will be never accepted; many of them can make the listener queue full and preventing the creation of MPJ subflow via such listener - its intended role. Explicitly detect this scenario at initial-syn time and drop the incoming MPC request. Fixes: 1729cf1 ("mptcp: create the listening socket for new port") Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e Cc: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Message-Id: <20241007-mpc-hs-port-v2-1-0c9e7827bd0f@kernel.org>

Syzkaller reported a lockdep splat: ============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted -------------------------------------------- syz-executor364/5113 is trying to acquire lock: ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 but task is already holding lock: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-slock-AF_INET); lock(k-slock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor364/5113: #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806 #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228 #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232 #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 stack backtrace: CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279 subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874 tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853 tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 </IRQ> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235 ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline] tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729 tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x214/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733 mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04fb13a6b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9 RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004 RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300 </TASK> As noted by Cong Wang, the splat is false positive, but the code path leading to the report is an unexpected one: a client is attempting an MPC handshake towards the in-kernel listener created by the in-kernel PM for a port based signal endpoint. Such connection will be never accepted; many of them can make the listener queue full and preventing the creation of MPJ subflow via such listener - its intended role. Explicitly detect this scenario at initial-syn time and drop the incoming MPC request. Fixes: 1729cf1 ("mptcp: create the listening socket for new port") Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e Cc: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Message-Id: <20241008-mpc-hs-port-v3-1-cec1363f0353@kernel.org>

Daniel Machon says: ==================== net: sparx5: prepare for lan969x switch driver == Description: This series is the first of a multi-part series, that prepares and adds support for the new lan969x switch driver. The upstreaming efforts is split into multiple series (might change a bit as we go along): 1) Prepare the Sparx5 driver for lan969x (this series) 2) Add support lan969x (same basic features as Sparx5 provides + RGMII, excl. FDMA and VCAP) 3) Add support for lan969x FDMA 4) Add support for lan969x VCAP == Lan969x in short: The lan969x Ethernet switch family [1] provides a rich set of switching features and port configurations (up to 30 ports) from 10Mbps to 10Gbps, with support for RGMII, SGMII, QSGMII, USGMII, and USXGMII, ideal for industrial & process automation infrastructure applications, transport, grid automation, power substation automation, and ring & intra-ring topologies. The LAN969x family is hardware and software compatible and scalable supporting 46Gbps to 102Gbps switch bandwidths. == Preparing Sparx5 for lan969x: The lan969x switch chip reuses many of the IP's of the Sparx5 switch chip, therefore it has been decided to add support through the existing Sparx5 driver, in order to avoid a bunch of duplicate code. However, in order to reuse the Sparx5 switch driver, we have to introduce some mechanisms to handle the chip differences that are there. These mechanisms are: - Platform match data to contain all the differences that needs to be handled (constants, ops etc.) - Register macro indirection layer so that we can reuse the existing register macros. - Function for branching out on platform type where required. In some places we ops out functions and in other places we branch on the chip type. Exactly when we choose one over the other, is an estimate in each case. After this series is applied, the Sparx5 driver will be prepared for lan969x and still function exactly as before. == Patch breakdown: Patch #1 adds private match data Patch #2 adds register macro indirection layer Patch #3-#4 does some preparation work Patch #5-#7 adds chip constants and updates the code to use them Patch #8-#13 adds and uses ops for handling functions differently on the two platforms. Patch #14 adds and uses a macro for branching out on the chip type. Patch #15 (NEW) redefines macros for internal ports and PGID's. [1] https://www.microchip.com/en-us/product/lan9698 To: David S. Miller <davem@davemloft.net> To: Eric Dumazet <edumazet@google.com> To: Jakub Kicinski <kuba@kernel.org> To: Paolo Abeni <pabeni@redhat.com> To: Lars Povlsen <lars.povlsen@microchip.com> To: Steen Hegelund <Steen.Hegelund@microchip.com> To: horatiu.vultur@microchip.com To: jensemil.schulzostergaard@microchip.com To: UNGLinuxDriver@microchip.com To: Richard Cochran <richardcochran@gmail.com> To: horms@kernel.org To: justinstitt@google.com To: gal@nvidia.com To: aakash.r.menon@gmail.com To: jacob.e.keller@intel.com To: ast@fiberby.net Cc: netdev@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Machon <daniel.machon@microchip.com> ==================== Link: https://patch.msgid.link/20241004-b4-sparx5-lan969x-switch-driver-v2-0-d3290f581663@microchip.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Syzkaller reported a lockdep splat: ============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted -------------------------------------------- syz-executor364/5113 is trying to acquire lock: ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 but task is already holding lock: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-slock-AF_INET); lock(k-slock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor364/5113: #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806 #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228 #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232 #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 stack backtrace: CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279 subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874 tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853 tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 </IRQ> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235 ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline] tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729 tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x214/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733 mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04fb13a6b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9 RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004 RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300 </TASK> As noted by Cong Wang, the splat is false positive, but the code path leading to the report is an unexpected one: a client is attempting an MPC handshake towards the in-kernel listener created by the in-kernel PM for a port based signal endpoint. Such connection will be never accepted; many of them can make the listener queue full and preventing the creation of MPJ subflow via such listener - its intended role. Explicitly detect this scenario at initial-syn time and drop the incoming MPC request. Fixes: 1729cf1 ("mptcp: create the listening socket for new port") Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e Cc: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Mat Martineau <martineau@kernel.org>

Eric Dumazet says: ==================== net: remove RTNL from fib_seq_sum() This series is inspired by a syzbot report showing rtnl contention and one thread blocked in: 7 locks held by syz-executor/10835: #0: ffff888033390420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #0: ffff888033390420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff88806df6bc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888026fcf3c8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f56f848 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166 #4: ffff88805e0140e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88805e0140e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005 #5: ffff88805c5fb250 (&devlink->lock_key#55){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1534 #6: ffffffff8fcd1748 (rtnl_mutex){+.+.}-{3:3}, at: fib_seq_sum+0x31/0x290 net/core/fib_notifier.c:46 ==================== Link: https://patch.msgid.link/20241009184405.3752829-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Danielle Ratson says: ==================== ethtool: Add support for writing firmware In the CMIS specification for pluggable modules, LPL (Local Payload) and EPL (Extended Payload) are two types of data payloads used for managing various functions and features of the module. EPL payloads are used for more complex and extensive management functions that require a larger amount of data, so writing firmware blocks using EPL is much more efficient. Currently, only LPL payload is supported for writing firmware blocks to the module. Add support for writing firmware block using EPL payload, both to support modules that support only EPL write mechanism, and to optimize the flashing process of modules that support LPL and EPL. Running the flashing command on the same sample module using EPL vs. LPL showed an improvement of 84%. Patchset overview: Patch #1: preparations Patch #2: Add EPL support v5: Resending- no changes. v4: Resending the right version after wrong v3. No changes from v2. v2: * Fix the commit meassges to align the cover letter about the right meaning of LPL and EPL. Patch #2: * Initialize the variable 'bytes_written' before the first iteration. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>

Syzkaller reported a lockdep splat: ============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Not tainted -------------------------------------------- syz-executor364/5113 is trying to acquire lock: ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880449f1958 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 but task is already holding lock: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-slock-AF_INET); lock(k-slock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor364/5113: #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880449f0e18 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x153/0x1b10 net/mptcp/protocol.c:1806 #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #1: ffff88803fe39ad8 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg_fastopen+0x11f/0x530 net/mptcp/protocol.c:1727 #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x5f/0x1b80 net/ipv4/ip_output.c:470 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1390 net/ipv4/ip_output.c:228 #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #4: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x230/0x5f0 net/ipv4/ip_input.c:232 #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #6: ffff88803fe3cb58 (k-slock-AF_INET){+.-.}-{2:2}, at: sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 stack backtrace: CPU: 0 UID: 0 PID: 5113 Comm: syz-executor364 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] sk_clone_lock+0x2cd/0xf40 net/core/sock.c:2328 mptcp_sk_clone_init+0x32/0x13c0 net/mptcp/protocol.c:3279 subflow_syn_recv_sock+0x931/0x1920 net/mptcp/subflow.c:874 tcp_check_req+0xfe4/0x1a20 net/ipv4/tcp_minisocks.c:853 tcp_v4_rcv+0x1c3e/0x37f0 net/ipv4/tcp_ipv4.c:2267 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 </IRQ> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235 ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6542 [inline] tcp_rcv_state_process+0x2c32/0x4570 net/ipv4/tcp_input.c:6729 tcp_v4_do_rcv+0x77d/0xc70 net/ipv4/tcp_ipv4.c:1934 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x214/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 mptcp_sendmsg_fastopen+0x1ad/0x530 net/mptcp/protocol.c:1733 mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1812 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04fb13a6b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd651f42d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f04fb13a6b9 RDX: 0000000000000001 RSI: 0000000020000d00 RDI: 0000000000000004 RBP: 00007ffd651f4310 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000020000080 R11: 0000000000000246 R12: 00000000000f4240 R13: 00007f04fb187449 R14: 00007ffd651f42f4 R15: 00007ffd651f4300 </TASK> As noted by Cong Wang, the splat is false positive, but the code path leading to the report is an unexpected one: a client is attempting an MPC handshake towards the in-kernel listener created by the in-kernel PM for a port based signal endpoint. Such connection will be never accepted; many of them can make the listener queue full and preventing the creation of MPJ subflow via such listener - its intended role. Explicitly detect this scenario at initial-syn time and drop the incoming MPC request. Fixes: 1729cf1 ("mptcp: create the listening socket for new port") Reported-by: syzbot+f4aacdfef2c6a6529c3e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f4aacdfef2c6a6529c3e Cc: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Mat Martineau <martineau@kernel.org>

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reduce hooking in TCP code #2

reduce hooking in TCP code #2

pabeni commented Mar 19, 2020

reduce hooking in TCP code #2

reduce hooking in TCP code #2

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pabeni commented Mar 19, 2020