syzbot


possible deadlock in io_timeout_fn (2)

Status: fixed on 2021/03/10 01:48
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+91ca3f25bd7f795f019c@syzkaller.appspotmail.com
Fix commit: 4aa84f2ffa81 io_uring: dont kill fasync under completion_lock
First crash: 1269d, last: 1258d
Discussions (4)
Title Replies (including bot) Last reply
[PATCH 0/3] commit/posted fixes 5 (5) 2021/01/07 14:48
[PATCH v2 0/6] bunch of random fixes 8 (8) 2021/01/04 16:27
[PATCH 0/4] bunch of random fixes 9 (9) 2021/01/03 22:05
possible deadlock in io_timeout_fn (2) 0 (1) 2020/12/31 16:59
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in io_timeout_fn io-uring fs C done 4 1406d 1408d 15/27 fixed on 2020/09/16 22:51

Sample crash report:
=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
5.11.0-rc2-syzkaller #0 Not tainted
-----------------------------------------------------
syz-executor.5/29658 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff88801211d948 (&new->fa_lock){.?.?}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:1004 [inline]
ffff88801211d948 (&new->fa_lock){.?.?}-{2:2}, at: kill_fasync fs/fcntl.c:1025 [inline]
ffff88801211d948 (&new->fa_lock){.?.?}-{2:2}, at: kill_fasync+0x14b/0x460 fs/fcntl.c:1018

and this task is already holding:
ffff88805e538498 (&ctx->completion_lock#2){-...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:379 [inline]
ffff88805e538498 (&ctx->completion_lock#2){-...}-{2:2}, at: io_submit_flush_completions+0x4d/0x3a0 fs/io_uring.c:1833
which would create a new lock dependency:
 (&ctx->completion_lock#2){-...}-{2:2} -> (&new->fa_lock){.?.?}-{2:2}

but this new dependency connects a HARDIRQ-irq-safe lock:
 (&ctx->completion_lock#2){-...}-{2:2}

... which became HARDIRQ-irq-safe at:
  lock_acquire kernel/locking/lockdep.c:5437 [inline]
  lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159
  io_timeout_fn+0x6f/0x3d0 fs/io_uring.c:5623
  __run_hrtimer kernel/time/hrtimer.c:1519 [inline]
  __hrtimer_run_queues+0x693/0xea0 kernel/time/hrtimer.c:1583
  hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645
  local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
  __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102
  asm_call_irq_on_stack+0xf/0x20
  __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline]
  run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline]
  sysvec_apic_timer_interrupt+0xbd/0x100 arch/x86/kernel/apic/apic.c:1096
  asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
  __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
  _raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199
  spin_unlock_irq include/linux/spinlock.h:404 [inline]
  io_timeout fs/io_uring.c:5827 [inline]
  io_issue_sqe+0x1cf3/0x4490 fs/io_uring.c:6221
  __io_queue_sqe+0x228/0x10c0 fs/io_uring.c:6488
  io_queue_sqe+0x631/0x10d0 fs/io_uring.c:6554
  io_queue_link_head fs/io_uring.c:6565 [inline]
  io_submit_sqes+0xac1/0x2720 fs/io_uring.c:6890
  __do_sys_io_uring_enter+0x6d1/0x1e70 fs/io_uring.c:9214
  do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

to a HARDIRQ-irq-unsafe lock:
 (&new->fa_lock){.?.?}-{2:2}

... which became HARDIRQ-irq-unsafe at:
...
  lock_acquire kernel/locking/lockdep.c:5437 [inline]
  lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
  __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
  _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
  kill_fasync_rcu fs/fcntl.c:1004 [inline]
  kill_fasync fs/fcntl.c:1025 [inline]
  kill_fasync+0x14b/0x460 fs/fcntl.c:1018
  sock_wake_async+0xd2/0x160 net/socket.c:1310
  sk_wake_async include/net/sock.h:2279 [inline]
  sk_wake_async+0x16c/0x280 include/net/sock.h:2275
  unix_shutdown+0x3d6/0x540 net/unix/af_unix.c:2537
  __sys_shutdown_sock net/socket.c:2184 [inline]
  __sys_shutdown_sock net/socket.c:2178 [inline]
  __sys_shutdown+0xf1/0x1b0 net/socket.c:2196
  __do_sys_shutdown net/socket.c:2204 [inline]
  __se_sys_shutdown net/socket.c:2202 [inline]
  __x64_sys_shutdown+0x50/0x70 net/socket.c:2202
  do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&new->fa_lock);
                               local_irq_disable();
                               lock(&ctx->completion_lock#2);
                               lock(&new->fa_lock);
  <Interrupt>
    lock(&ctx->completion_lock#2);

 *** DEADLOCK ***

3 locks held by syz-executor.5/29658:
 #0: ffff88805e5383e8 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0x6c6/0x1e70 fs/io_uring.c:9213
 #1: ffff88805e538498 (&ctx->completion_lock#2){-...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:379 [inline]
 #1: ffff88805e538498 (&ctx->completion_lock#2){-...}-{2:2}, at: io_submit_flush_completions+0x4d/0x3a0 fs/io_uring.c:1833
 #2: ffffffff8b363860 (rcu_read_lock){....}-{1:2}, at: kill_fasync+0x3d/0x460 fs/fcntl.c:1023

the dependencies between HARDIRQ-irq-safe lock and the holding lock:
-> (&ctx->completion_lock#2){-...}-{2:2} {
   IN-HARDIRQ-W at:
                    lock_acquire kernel/locking/lockdep.c:5437 [inline]
                    lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
                    __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                    _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159
                    io_timeout_fn+0x6f/0x3d0 fs/io_uring.c:5623
                    __run_hrtimer kernel/time/hrtimer.c:1519 [inline]
                    __hrtimer_run_queues+0x693/0xea0 kernel/time/hrtimer.c:1583
                    hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645
                    local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
                    __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102
                    asm_call_irq_on_stack+0xf/0x20
                    __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline]
                    run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline]
                    sysvec_apic_timer_interrupt+0xbd/0x100 arch/x86/kernel/apic/apic.c:1096
                    asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
                    __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
                    _raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199
                    spin_unlock_irq include/linux/spinlock.h:404 [inline]
                    io_timeout fs/io_uring.c:5827 [inline]
                    io_issue_sqe+0x1cf3/0x4490 fs/io_uring.c:6221
                    __io_queue_sqe+0x228/0x10c0 fs/io_uring.c:6488
                    io_queue_sqe+0x631/0x10d0 fs/io_uring.c:6554
                    io_queue_link_head fs/io_uring.c:6565 [inline]
                    io_submit_sqes+0xac1/0x2720 fs/io_uring.c:6890
                    __do_sys_io_uring_enter+0x6d1/0x1e70 fs/io_uring.c:9214
                    do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
                    entry_SYSCALL_64_after_hwframe+0x44/0xa9
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5437 [inline]
                   lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
                   __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
                   _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:167
                   spin_lock_irq include/linux/spinlock.h:379 [inline]
                   io_cancel_defer_files fs/io_uring.c:8757 [inline]
                   io_uring_cancel_task_requests fs/io_uring.c:8858 [inline]
                   __io_uring_files_cancel+0x2f0/0x14f0 fs/io_uring.c:8963
                   io_uring_files_cancel include/linux/io_uring.h:51 [inline]
                   do_exit+0x2fe/0x2ae0 kernel/exit.c:780
                   do_group_exit+0x125/0x310 kernel/exit.c:922
                   get_signal+0x3ec/0x2010 kernel/signal.c:2770
                   arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
                   handle_signal_work kernel/entry/common.c:147 [inline]
                   exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
                   exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201
                   __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
                   syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
                   entry_SYSCALL_64_after_hwframe+0x44/0xa9
 }
 ... key      at: [<ffffffff8ef92a60>] __key.10+0x0/0x40
 ... acquired at:
   lock_acquire kernel/locking/lockdep.c:5437 [inline]
   lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
   __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
   _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
   kill_fasync_rcu fs/fcntl.c:1004 [inline]
   kill_fasync fs/fcntl.c:1025 [inline]
   kill_fasync+0x14b/0x460 fs/fcntl.c:1018
   __io_commit_cqring fs/io_uring.c:1348 [inline]
   io_commit_cqring+0x34e/0xa90 fs/io_uring.c:1658
   io_submit_flush_completions+0x269/0x3a0 fs/io_uring.c:1855
   __io_req_complete+0x209/0x310 fs/io_uring.c:1874
   io_nop fs/io_uring.c:3897 [inline]
   io_issue_sqe+0x1234/0x4490 fs/io_uring.c:6184
   __io_queue_sqe+0x228/0x10c0 fs/io_uring.c:6488
   io_queue_sqe+0x631/0x10d0 fs/io_uring.c:6554
   io_submit_sqe fs/io_uring.c:6627 [inline]
   io_submit_sqes+0x1495/0x2720 fs/io_uring.c:6875
   __do_sys_io_uring_enter+0x6d1/0x1e70 fs/io_uring.c:9214
   do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
   entry_SYSCALL_64_after_hwframe+0x44/0xa9


the dependencies between the lock to be acquired
 and HARDIRQ-irq-unsafe lock:
-> (&new->fa_lock){.?.?}-{2:2} {
   IN-HARDIRQ-R at:
                    lock_acquire kernel/locking/lockdep.c:5437 [inline]
                    lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
                    __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                    _raw_read_lock+0x36/0x70 kernel/locking/spinlock.c:223
                    kill_fasync_rcu fs/fcntl.c:1004 [inline]
                    kill_fasync fs/fcntl.c:1025 [inline]
                    kill_fasync+0x14b/0x460 fs/fcntl.c:1018
                    perf_event_wakeup kernel/events/core.c:6277 [inline]
                    perf_pending_event+0x221/0x310 kernel/events/core.c:6333
                    irq_work_single+0x120/0x1f0 kernel/irq_work.c:153
                    irq_work_run_list+0x91/0xc0 kernel/irq_work.c:175
                    irq_work_run+0x54/0xd0 kernel/irq_work.c:184
                    __sysvec_irq_work+0x95/0x3d0 arch/x86/kernel/irq_work.c:22
                    run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline]
                    sysvec_irq_work+0x48/0x100 arch/x86/kernel/irq_work.c:17
                    asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:654
   HARDIRQ-ON-R at:
                    lock_acquire kernel/locking/lockdep.c:5437 [inline]
                    lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
                    __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                    _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
                    kill_fasync_rcu fs/fcntl.c:1004 [inline]
                    kill_fasync fs/fcntl.c:1025 [inline]
                    kill_fasync+0x14b/0x460 fs/fcntl.c:1018
                    sock_wake_async+0xd2/0x160 net/socket.c:1310
                    sk_wake_async include/net/sock.h:2279 [inline]
                    sk_wake_async+0x16c/0x280 include/net/sock.h:2275
                    unix_shutdown+0x3d6/0x540 net/unix/af_unix.c:2537
                    __sys_shutdown_sock net/socket.c:2184 [inline]
                    __sys_shutdown_sock net/socket.c:2178 [inline]
                    __sys_shutdown+0xf1/0x1b0 net/socket.c:2196
                    __do_sys_shutdown net/socket.c:2204 [inline]
                    __se_sys_shutdown net/socket.c:2202 [inline]
                    __x64_sys_shutdown+0x50/0x70 net/socket.c:2202
                    do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
                    entry_SYSCALL_64_after_hwframe+0x44/0xa9
   IN-SOFTIRQ-R at:
                    lock_acquire kernel/locking/lockdep.c:5437 [inline]
                    lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
                    __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                    _raw_read_lock+0x36/0x70 kernel/locking/spinlock.c:223
                    kill_fasync_rcu fs/fcntl.c:1004 [inline]
                    kill_fasync fs/fcntl.c:1025 [inline]
                    kill_fasync+0x14b/0x460 fs/fcntl.c:1018
                    perf_event_wakeup kernel/events/core.c:6277 [inline]
                    perf_pending_event+0x221/0x310 kernel/events/core.c:6333
                    irq_work_single+0x120/0x1f0 kernel/irq_work.c:153
                    irq_work_run_list+0x91/0xc0 kernel/irq_work.c:175
                    irq_work_run+0x54/0xd0 kernel/irq_work.c:184
                    __sysvec_irq_work+0x95/0x3d0 arch/x86/kernel/irq_work.c:22
                    run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline]
                    sysvec_irq_work+0x48/0x100 arch/x86/kernel/irq_work.c:17
                    asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:654
                    __do_softirq+0x199/0x9f7 kernel/softirq.c:329
                    asm_call_irq_on_stack+0xf/0x20
                    __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
                    run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
                    do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77
                    invoke_softirq kernel/softirq.c:226 [inline]
                    __irq_exit_rcu kernel/softirq.c:420 [inline]
                    irq_exit_rcu+0x134/0x200 kernel/softirq.c:432
                    sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096
                    asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
   SOFTIRQ-ON-R at:
                    lock_acquire kernel/locking/lockdep.c:5437 [inline]
                    lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
                    __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                    _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
                    kill_fasync_rcu fs/fcntl.c:1004 [inline]
                    kill_fasync fs/fcntl.c:1025 [inline]
                    kill_fasync+0x14b/0x460 fs/fcntl.c:1018
                    sock_wake_async+0xd2/0x160 net/socket.c:1310
                    sk_wake_async include/net/sock.h:2279 [inline]
                    sk_wake_async+0x16c/0x280 include/net/sock.h:2275
                    unix_shutdown+0x3d6/0x540 net/unix/af_unix.c:2537
                    __sys_shutdown_sock net/socket.c:2184 [inline]
                    __sys_shutdown_sock net/socket.c:2178 [inline]
                    __sys_shutdown+0xf1/0x1b0 net/socket.c:2196
                    __do_sys_shutdown net/socket.c:2204 [inline]
                    __se_sys_shutdown net/socket.c:2202 [inline]
                    __x64_sys_shutdown+0x50/0x70 net/socket.c:2202
                    do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
                    entry_SYSCALL_64_after_hwframe+0x44/0xa9
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5437 [inline]
                   lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline]
                   _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:311
                   fasync_remove_entry+0xb6/0x1f0 fs/fcntl.c:882
                   fasync_helper+0x9e/0xb0 fs/fcntl.c:985
                   perf_fasync+0x7e/0xb0 kernel/events/core.c:6237
                   __fput+0x70d/0x920 fs/file_table.c:277
                   task_work_run+0xdd/0x190 kernel/task_work.c:140
                   tracehook_notify_resume include/linux/tracehook.h:189 [inline]
                   exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
                   exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201
                   __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
                   syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
                   entry_SYSCALL_64_after_hwframe+0x44/0xa9
   INITIAL READ USE at:
                        lock_acquire kernel/locking/lockdep.c:5437 [inline]
                        lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
                        __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                        _raw_read_lock+0x36/0x70 kernel/locking/spinlock.c:223
                        kill_fasync_rcu fs/fcntl.c:1004 [inline]
                        kill_fasync fs/fcntl.c:1025 [inline]
                        kill_fasync+0x14b/0x460 fs/fcntl.c:1018
                        perf_event_wakeup kernel/events/core.c:6277 [inline]
                        perf_pending_event+0x221/0x310 kernel/events/core.c:6333
                        irq_work_single+0x120/0x1f0 kernel/irq_work.c:153
                        irq_work_run_list+0x91/0xc0 kernel/irq_work.c:175
                        irq_work_run+0x54/0xd0 kernel/irq_work.c:184
                        __sysvec_irq_work+0x95/0x3d0 arch/x86/kernel/irq_work.c:22
                        run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline]
                        sysvec_irq_work+0x48/0x100 arch/x86/kernel/irq_work.c:17
                        asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:654
 }
 ... key      at: [<ffffffff8ef8e980>] __key.0+0x0/0x40
 ... acquired at:
   lock_acquire kernel/locking/lockdep.c:5437 [inline]
   lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
   __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
   _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
   kill_fasync_rcu fs/fcntl.c:1004 [inline]
   kill_fasync fs/fcntl.c:1025 [inline]
   kill_fasync+0x14b/0x460 fs/fcntl.c:1018
   __io_commit_cqring fs/io_uring.c:1348 [inline]
   io_commit_cqring+0x34e/0xa90 fs/io_uring.c:1658
   io_submit_flush_completions+0x269/0x3a0 fs/io_uring.c:1855
   __io_req_complete+0x209/0x310 fs/io_uring.c:1874
   io_nop fs/io_uring.c:3897 [inline]
   io_issue_sqe+0x1234/0x4490 fs/io_uring.c:6184
   __io_queue_sqe+0x228/0x10c0 fs/io_uring.c:6488
   io_queue_sqe+0x631/0x10d0 fs/io_uring.c:6554
   io_submit_sqe fs/io_uring.c:6627 [inline]
   io_submit_sqes+0x1495/0x2720 fs/io_uring.c:6875
   __do_sys_io_uring_enter+0x6d1/0x1e70 fs/io_uring.c:9214
   do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
   entry_SYSCALL_64_after_hwframe+0x44/0xa9


stack backtrace:
CPU: 0 PID: 29658 Comm: syz-executor.5 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 print_bad_irq_dependency kernel/locking/lockdep.c:2452 [inline]
 check_irq_usage.cold+0x4f5/0x6c8 kernel/locking/lockdep.c:2681
 check_prev_add kernel/locking/lockdep.c:2872 [inline]
 check_prevs_add kernel/locking/lockdep.c:2993 [inline]
 validate_chain kernel/locking/lockdep.c:3608 [inline]
 __lock_acquire+0x2af6/0x5500 kernel/locking/lockdep.c:4832
 lock_acquire kernel/locking/lockdep.c:5437 [inline]
 lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
 _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
 kill_fasync_rcu fs/fcntl.c:1004 [inline]
 kill_fasync fs/fcntl.c:1025 [inline]
 kill_fasync+0x14b/0x460 fs/fcntl.c:1018
 __io_commit_cqring fs/io_uring.c:1348 [inline]
 io_commit_cqring+0x34e/0xa90 fs/io_uring.c:1658
 io_submit_flush_completions+0x269/0x3a0 fs/io_uring.c:1855
 __io_req_complete+0x209/0x310 fs/io_uring.c:1874
 io_nop fs/io_uring.c:3897 [inline]
 io_issue_sqe+0x1234/0x4490 fs/io_uring.c:6184
 __io_queue_sqe+0x228/0x10c0 fs/io_uring.c:6488
 io_queue_sqe+0x631/0x10d0 fs/io_uring.c:6554
 io_submit_sqe fs/io_uring.c:6627 [inline]
 io_submit_sqes+0x1495/0x2720 fs/io_uring.c:6875
 __do_sys_io_uring_enter+0x6d1/0x1e70 fs/io_uring.c:9214
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e219
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007efea91a0c68 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045e219
RDX: 0000000000000000 RSI: 000000000000450c RDI: 0000000000000003
RBP: 000000000119c080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034
R13: 00000000016afb5f R14: 00007efea91a19c0 R15: 000000000119c034

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/07 09:08 upstream 71c061d24438 c104d4a3 .config console log report info ci-upstream-kasan-gce
2020/12/31 03:53 upstream f6e1ea196492 5cc121d6 .config console log report info ci-upstream-kasan-gce-selinux-root
2020/12/30 02:53 upstream 139711f033f6 0fa352f2 .config console log report info ci-upstream-kasan-gce
2020/12/27 16:52 upstream f838f8d2b694 2242f77f .config console log report info ci-upstream-kasan-gce
* Struck through repros no longer work on HEAD.