syzbot


possible deadlock in snd_timer_notify

Status: fixed on 2021/11/10 00:50
Subsystems: fs
[Documentation on labels]
Fix commit: f671a691e299 fcntl: fix potential deadlocks for &fown_struct.lock
First crash: 1018d, last: 912d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in snd_timer_notify (2) fs 151 643d 907d 22/26 fixed on 2023/02/24 13:50

Sample crash report:
=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.15.0-syzkaller #0 Not tainted
-----------------------------------------------------
syz-executor.2/7781 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff88801ce03018 (&new->fa_lock){....}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:1014 [inline]
ffff88801ce03018 (&new->fa_lock){....}-{2:2}, at: kill_fasync fs/fcntl.c:1035 [inline]
ffff88801ce03018 (&new->fa_lock){....}-{2:2}, at: kill_fasync+0x136/0x470 fs/fcntl.c:1028

and this task is already holding:
ffff888021d50148 (&timer->lock){..-.}-{2:2}, at: snd_timer_start1+0x5a/0x800 sound/core/timer.c:541
which would create a new lock dependency:
 (&timer->lock){..-.}-{2:2} -> (&new->fa_lock){....}-{2:2}

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

... which became SOFTIRQ-irq-safe at:
  lock_acquire kernel/locking/lockdep.c:5640 [inline]
  lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
  snd_timer_notify sound/core/timer.c:1087 [inline]
  snd_timer_notify+0x10c/0x3d0 sound/core/timer.c:1074
  snd_pcm_timer_notify sound/core/pcm_native.c:595 [inline]
  snd_pcm_post_stop+0x195/0x1f0 sound/core/pcm_native.c:1453
  snd_pcm_action_single sound/core/pcm_native.c:1229 [inline]
  snd_pcm_drain_done+0xdc/0x120 sound/core/pcm_native.c:1491
  snd_pcm_update_state+0x43b/0x540 sound/core/pcm_lib.c:191
  snd_pcm_update_hw_ptr0+0xa75/0x1a50 sound/core/pcm_lib.c:465
  snd_pcm_period_elapsed_under_stream_lock+0x15a/0x230 sound/core/pcm_lib.c:1817
  snd_pcm_period_elapsed+0x28/0x50 sound/core/pcm_lib.c:1849
  loopback_jiffies_timer_function+0x1c4/0x240 sound/drivers/aloop.c:668
  call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
  expire_timers kernel/time/timer.c:1466 [inline]
  __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
  __run_timers kernel/time/timer.c:1715 [inline]
  run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
  __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
  invoke_softirq kernel/softirq.c:432 [inline]
  __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636
  irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
  sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
  asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
  __sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:917
  console_unlock+0x6c2/0xb70 kernel/printk/printk.c:2716
  vprintk_emit+0x198/0x4f0 kernel/printk/printk.c:2245
  vprintk+0x80/0x90 kernel/printk/printk_safe.c:50
  _printk+0xba/0xed kernel/printk/printk.c:2266
  nvmf_check_required_opts drivers/nvme/host/fabrics.c:878 [inline]
  nvmf_check_required_opts drivers/nvme/host/fabrics.c:869 [inline]
  nvmf_create_ctrl drivers/nvme/host/fabrics.c:983 [inline]
  nvmf_dev_write+0x1fcc/0x2480 drivers/nvme/host/fabrics.c:1055
  vfs_write+0x28e/0xae0 fs/read_write.c:588
  ksys_write+0x12d/0x250 fs/read_write.c:643
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

to a SOFTIRQ-irq-unsafe lock:
 (tasklist_lock){.+.+}-{2:2}

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire kernel/locking/lockdep.c:5640 [inline]
  lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
  __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
  _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228
  do_wait+0x284/0xce0 kernel/exit.c:1511
  kernel_wait+0x9c/0x150 kernel/exit.c:1701
  call_usermodehelper_exec_sync kernel/umh.c:139 [inline]
  call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166
  process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
  worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
  kthread+0x405/0x4f0 kernel/kthread.c:327
  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

other info that might help us debug this:

Chain exists of:
  &timer->lock --> &new->fa_lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(&timer->lock);
                               lock(&new->fa_lock);
  <Interrupt>
    lock(&timer->lock);

 *** DEADLOCK ***

3 locks held by syz-executor.2/7781:
 #0: ffff88801cda6968 (&tu->ioctl_lock){+.+.}-{3:3}, at: snd_timer_user_ioctl+0x4c/0xb0 sound/core/timer.c:2128
 #1: ffff888021d50148 (&timer->lock){..-.}-{2:2}, at: snd_timer_start1+0x5a/0x800 sound/core/timer.c:541
 #2: ffffffff8b983a20 (rcu_read_lock){....}-{1:2}, at: kill_fasync+0x41/0x470 fs/fcntl.c:1033

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&timer->lock){..-.}-{2:2} {
   IN-SOFTIRQ-W at:
                    lock_acquire kernel/locking/lockdep.c:5640 [inline]
                    lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                    __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                    _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
                    snd_timer_notify sound/core/timer.c:1087 [inline]
                    snd_timer_notify+0x10c/0x3d0 sound/core/timer.c:1074
                    snd_pcm_timer_notify sound/core/pcm_native.c:595 [inline]
                    snd_pcm_post_stop+0x195/0x1f0 sound/core/pcm_native.c:1453
                    snd_pcm_action_single sound/core/pcm_native.c:1229 [inline]
                    snd_pcm_drain_done+0xdc/0x120 sound/core/pcm_native.c:1491
                    snd_pcm_update_state+0x43b/0x540 sound/core/pcm_lib.c:191
                    snd_pcm_update_hw_ptr0+0xa75/0x1a50 sound/core/pcm_lib.c:465
                    snd_pcm_period_elapsed_under_stream_lock+0x15a/0x230 sound/core/pcm_lib.c:1817
                    snd_pcm_period_elapsed+0x28/0x50 sound/core/pcm_lib.c:1849
                    loopback_jiffies_timer_function+0x1c4/0x240 sound/drivers/aloop.c:668
                    call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
                    expire_timers kernel/time/timer.c:1466 [inline]
                    __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
                    __run_timers kernel/time/timer.c:1715 [inline]
                    run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
                    __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
                    invoke_softirq kernel/softirq.c:432 [inline]
                    __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636
                    irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
                    sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
                    asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
                    __sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:917
                    console_unlock+0x6c2/0xb70 kernel/printk/printk.c:2716
                    vprintk_emit+0x198/0x4f0 kernel/printk/printk.c:2245
                    vprintk+0x80/0x90 kernel/printk/printk_safe.c:50
                    _printk+0xba/0xed kernel/printk/printk.c:2266
                    nvmf_check_required_opts drivers/nvme/host/fabrics.c:878 [inline]
                    nvmf_check_required_opts drivers/nvme/host/fabrics.c:869 [inline]
                    nvmf_create_ctrl drivers/nvme/host/fabrics.c:983 [inline]
                    nvmf_dev_write+0x1fcc/0x2480 drivers/nvme/host/fabrics.c:1055
                    vfs_write+0x28e/0xae0 fs/read_write.c:588
                    ksys_write+0x12d/0x250 fs/read_write.c:643
                    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
                    do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
                    entry_SYSCALL_64_after_hwframe+0x44/0xae
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5640 [inline]
                   lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                   __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
                   _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:170
                   __snd_timer_user_ioctl.isra.0+0xeaa/0x2490 include/linux/spinlock.h:375
                   snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129
                   vfs_ioctl fs/ioctl.c:51 [inline]
                   __do_sys_ioctl fs/ioctl.c:874 [inline]
                   __se_sys_ioctl fs/ioctl.c:860 [inline]
                   __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
                   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
                   do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
                   entry_SYSCALL_64_after_hwframe+0x44/0xae
 }
 ... key      at: [<ffffffff906045c0>] __key.12+0x0/0x40

the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
  -> (tasklist_lock){.+.+}-{2:2} {
     HARDIRQ-ON-R at:
                        lock_acquire kernel/locking/lockdep.c:5640 [inline]
                        lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                        __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                        _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228
                        do_wait+0x284/0xce0 kernel/exit.c:1511
                        kernel_wait+0x9c/0x150 kernel/exit.c:1701
                        call_usermodehelper_exec_sync kernel/umh.c:139 [inline]
                        call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166
                        process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
                        worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
                        kthread+0x405/0x4f0 kernel/kthread.c:327
                        ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
     SOFTIRQ-ON-R at:
                        lock_acquire kernel/locking/lockdep.c:5640 [inline]
                        lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                        __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                        _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228
                        do_wait+0x284/0xce0 kernel/exit.c:1511
                        kernel_wait+0x9c/0x150 kernel/exit.c:1701
                        call_usermodehelper_exec_sync kernel/umh.c:139 [inline]
                        call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166
                        process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
                        worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
                        kthread+0x405/0x4f0 kernel/kthread.c:327
                        ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
     INITIAL USE at:
                       lock_acquire kernel/locking/lockdep.c:5640 [inline]
                       lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                       __raw_write_lock_irq include/linux/rwlock_api_smp.h:194 [inline]
                       _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:316
                       copy_process+0x36c0/0x75a0 kernel/fork.c:2310
                       kernel_clone+0xe7/0xab0 kernel/fork.c:2581
                       kernel_thread+0xb5/0xf0 kernel/fork.c:2633
                       rest_init+0x23/0x3e0 init/main.c:690
                       start_kernel+0x47a/0x49b init/main.c:1133
                       secondary_startup_64_no_verify+0xb0/0xbb
     INITIAL READ USE at:
                            lock_acquire kernel/locking/lockdep.c:5640 [inline]
                            lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                            __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                            _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228
                            do_wait+0x284/0xce0 kernel/exit.c:1511
                            kernel_wait+0x9c/0x150 kernel/exit.c:1701
                            call_usermodehelper_exec_sync kernel/umh.c:139 [inline]
                            call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166
                            process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
                            worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
                            kthread+0x405/0x4f0 kernel/kthread.c:327
                            ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
   }
   ... key      at: [<ffffffff8b60a098>] tasklist_lock+0x18/0x40
   ... acquired at:
   __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
   _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228
   send_sigio+0xab/0x380 fs/fcntl.c:810
   kill_fasync_rcu fs/fcntl.c:1021 [inline]
   kill_fasync fs/fcntl.c:1035 [inline]
   kill_fasync+0x1f8/0x470 fs/fcntl.c:1028
   sock_wake_async+0xd2/0x160 net/socket.c:1368
   sk_wake_async include/net/sock.h:2400 [inline]
   sk_wake_async include/net/sock.h:2396 [inline]
   sock_def_readable+0x349/0x4e0 net/core/sock.c:3138
   unix_dgram_sendmsg+0xfa7/0x1950 net/unix/af_unix.c:1941
   sock_sendmsg_nosec net/socket.c:704 [inline]
   sock_sendmsg+0xcf/0x120 net/socket.c:724
   ____sys_sendmsg+0x331/0x810 net/socket.c:2409
   ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
   __sys_sendmmsg+0x195/0x470 net/socket.c:2549
   __do_sys_sendmmsg net/socket.c:2578 [inline]
   __se_sys_sendmmsg net/socket.c:2575 [inline]
   __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2575
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x44/0xae

 -> (&f->f_owner.lock){...-}-{2:2} {
    IN-SOFTIRQ-R at:
                      lock_acquire kernel/locking/lockdep.c:5640 [inline]
                      lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                      __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline]
                      _raw_read_lock_irqsave+0x45/0x90 kernel/locking/spinlock.c:236
                      send_sigurg+0x1e/0xaf0 fs/fcntl.c:835
                      sk_send_sigurg+0x76/0x310 net/core/sock.c:3172
                      tcp_check_urg.isra.0+0x1f3/0x710 net/ipv4/tcp_input.c:5567
                      tcp_urg net/ipv4/tcp_input.c:5608 [inline]
                      tcp_rcv_established+0x12ab/0x2130 net/ipv4/tcp_input.c:5942
                      tcp_v4_do_rcv+0x600/0x8d0 net/ipv4/tcp_ipv4.c:1716
                      tcp_v4_rcv+0x2768/0x3080 net/ipv4/tcp_ipv4.c:2110
                      ip_protocol_deliver_rcu+0xa7/0xee0 net/ipv4/ip_input.c:204
                      ip_local_deliver_finish+0x20a/0x370 net/ipv4/ip_input.c:231
                      NF_HOOK include/linux/netfilter.h:307 [inline]
                      NF_HOOK include/linux/netfilter.h:301 [inline]
                      ip_local_deliver+0x1b3/0x200 net/ipv4/ip_input.c:252
                      dst_input include/net/dst.h:460 [inline]
                      ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:429
                      NF_HOOK include/linux/netfilter.h:307 [inline]
                      NF_HOOK include/linux/netfilter.h:301 [inline]
                      ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:540
                      __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5462
                      __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5576
                      process_backlog+0x2a5/0x6c0 net/core/dev.c:6452
                      __napi_poll+0xaf/0x440 net/core/dev.c:7017
                      napi_poll net/core/dev.c:7084 [inline]
                      net_rx_action+0x801/0xb40 net/core/dev.c:7171
                      __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
                      run_ksoftirqd kernel/softirq.c:920 [inline]
                      run_ksoftirqd+0x2d/0x60 kernel/softirq.c:912
                      smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164
                      kthread+0x405/0x4f0 kernel/kthread.c:327
                      ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
    INITIAL USE at:
                     lock_acquire kernel/locking/lockdep.c:5640 [inline]
                     lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:194 [inline]
                     _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:316
                     f_modown+0x2a/0x390 fs/fcntl.c:91
                     fcntl_dirnotify+0x7c9/0xbc0 fs/notify/dnotify/dnotify.c:351
                     do_fcntl+0x269/0x1210 fs/fcntl.c:422
                     __do_sys_fcntl fs/fcntl.c:472 [inline]
                     __se_sys_fcntl fs/fcntl.c:457 [inline]
                     __x64_sys_fcntl+0x165/0x1e0 fs/fcntl.c:457
                     do_syscall_x64 arch/x86/entry/common.c:50 [inline]
                     do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
                     entry_SYSCALL_64_after_hwframe+0x44/0xae
    INITIAL READ USE at:
                          lock_acquire kernel/locking/lockdep.c:5640 [inline]
                          lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                          __raw_read_lock_irq include/linux/rwlock_api_smp.h:168 [inline]
                          _raw_read_lock_irq+0x63/0x80 kernel/locking/spinlock.c:244
                          f_getown+0x23/0x2a0 fs/fcntl.c:154
                          do_fcntl+0xbd8/0x1210 fs/fcntl.c:389
                          __do_sys_fcntl fs/fcntl.c:472 [inline]
                          __se_sys_fcntl fs/fcntl.c:457 [inline]
                          __x64_sys_fcntl+0x165/0x1e0 fs/fcntl.c:457
                          do_syscall_x64 arch/x86/entry/common.c:50 [inline]
                          do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
                          entry_SYSCALL_64_after_hwframe+0x44/0xae
  }
  ... key      at: [<ffffffff90305de0>] __key.5+0x0/0x40
  ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline]
   _raw_read_lock_irqsave+0x45/0x90 kernel/locking/spinlock.c:236
   send_sigio+0x24/0x380 fs/fcntl.c:796
   kill_fasync_rcu fs/fcntl.c:1021 [inline]
   kill_fasync fs/fcntl.c:1035 [inline]
   kill_fasync+0x1f8/0x470 fs/fcntl.c:1028
   sock_wake_async+0xd2/0x160 net/socket.c:1368
   sk_wake_async include/net/sock.h:2400 [inline]
   sk_wake_async include/net/sock.h:2396 [inline]
   sock_def_error_report+0x34b/0x4e0 net/core/sock.c:3125
   sk_error_report+0x35/0x310 net/core/sock.c:339
   sock_queue_err_skb+0x36b/0x7c0 net/core/skbuff.c:4773
   __skb_complete_tx_timestamp+0x308/0x420 net/core/skbuff.c:4868
   __skb_tstamp_tx+0x407/0x780 net/core/skbuff.c:4958
   __dev_queue_xmit+0x21fe/0x3630 net/core/dev.c:4154
   neigh_hh_output include/net/neighbour.h:511 [inline]
   neigh_output include/net/neighbour.h:525 [inline]
   ip_finish_output2+0x14cb/0x2160 net/ipv4/ip_output.c:221
   __ip_finish_output net/ipv4/ip_output.c:299 [inline]
   __ip_finish_output+0x396/0x640 net/ipv4/ip_output.c:281
   ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:309
   NF_HOOK_COND include/linux/netfilter.h:296 [inline]
   ip_output+0x196/0x310 net/ipv4/ip_output.c:423
   dst_output include/net/dst.h:450 [inline]
   ip_local_out net/ipv4/ip_output.c:126 [inline]
   ip_send_skb+0xd4/0x260 net/ipv4/ip_output.c:1555
   udp_send_skb+0x6cd/0x11a0 net/ipv4/udp.c:966
   udp_sendmsg+0x1bad/0x2740 net/ipv4/udp.c:1253
   inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
   sock_sendmsg_nosec net/socket.c:704 [inline]
   sock_sendmsg+0xcf/0x120 net/socket.c:724
   ____sys_sendmsg+0x331/0x810 net/socket.c:2409
   ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
   __sys_sendmmsg+0x195/0x470 net/socket.c:2549
   __do_sys_sendmmsg net/socket.c:2578 [inline]
   __se_sys_sendmmsg net/socket.c:2575 [inline]
   __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2575
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x44/0xae

-> (&new->fa_lock){....}-{2:2} {
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5640 [inline]
                   lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:194 [inline]
                   _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:316
                   fasync_remove_entry+0xb6/0x1f0 fs/fcntl.c:891
                   fasync_helper+0x9e/0xb0 fs/fcntl.c:994
                   sock_fasync+0x94/0x140 net/socket.c:1339
                   __fput+0x846/0x9f0 fs/file_table.c:277
                   task_work_run+0xdd/0x1a0 kernel/task_work.c:164
                   tracehook_notify_resume include/linux/tracehook.h:189 [inline]
                   exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
                   exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
                   __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
                   syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
                   do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
                   entry_SYSCALL_64_after_hwframe+0x44/0xae
   INITIAL READ USE at:
                        lock_acquire kernel/locking/lockdep.c:5640 [inline]
                        lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
                        __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline]
                        _raw_read_lock_irqsave+0x45/0x90 kernel/locking/spinlock.c:236
                        kill_fasync_rcu fs/fcntl.c:1014 [inline]
                        kill_fasync fs/fcntl.c:1035 [inline]
                        kill_fasync+0x136/0x470 fs/fcntl.c:1028
                        sock_wake_async+0xd2/0x160 net/socket.c:1368
                        sk_wake_async include/net/sock.h:2400 [inline]
                        sk_wake_async include/net/sock.h:2396 [inline]
                        sock_def_error_report+0x34b/0x4e0 net/core/sock.c:3125
                        sk_error_report+0x35/0x310 net/core/sock.c:339
                        sock_queue_err_skb+0x36b/0x7c0 net/core/skbuff.c:4773
                        __skb_complete_tx_timestamp+0x308/0x420 net/core/skbuff.c:4868
                        __skb_tstamp_tx+0x407/0x780 net/core/skbuff.c:4958
                        __dev_queue_xmit+0x21fe/0x3630 net/core/dev.c:4154
                        neigh_hh_output include/net/neighbour.h:511 [inline]
                        neigh_output include/net/neighbour.h:525 [inline]
                        ip_finish_output2+0x14cb/0x2160 net/ipv4/ip_output.c:221
                        __ip_finish_output net/ipv4/ip_output.c:299 [inline]
                        __ip_finish_output+0x396/0x640 net/ipv4/ip_output.c:281
                        ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:309
                        NF_HOOK_COND include/linux/netfilter.h:296 [inline]
                        ip_output+0x196/0x310 net/ipv4/ip_output.c:423
                        dst_output include/net/dst.h:450 [inline]
                        ip_local_out net/ipv4/ip_output.c:126 [inline]
                        ip_send_skb+0xd4/0x260 net/ipv4/ip_output.c:1555
                        udp_send_skb+0x6cd/0x11a0 net/ipv4/udp.c:966
                        udp_sendmsg+0x1bad/0x2740 net/ipv4/udp.c:1253
                        inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
                        sock_sendmsg_nosec net/socket.c:704 [inline]
                        sock_sendmsg+0xcf/0x120 net/socket.c:724
                        ____sys_sendmsg+0x331/0x810 net/socket.c:2409
                        ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
                        __sys_sendmmsg+0x195/0x470 net/socket.c:2549
                        __do_sys_sendmmsg net/socket.c:2578 [inline]
                        __se_sys_sendmmsg net/socket.c:2575 [inline]
                        __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2575
                        do_syscall_x64 arch/x86/entry/common.c:50 [inline]
                        do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
                        entry_SYSCALL_64_after_hwframe+0x44/0xae
 }
 ... key      at: [<ffffffff90306bc0>] __key.0+0x0/0x40
 ... acquired at:
   lock_acquire kernel/locking/lockdep.c:5640 [inline]
   lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline]
   _raw_read_lock_irqsave+0x70/0x90 kernel/locking/spinlock.c:236
   kill_fasync_rcu fs/fcntl.c:1014 [inline]
   kill_fasync fs/fcntl.c:1035 [inline]
   kill_fasync+0x136/0x470 fs/fcntl.c:1028
   snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1387
   snd_timer_notify1+0x11c/0x3b0 sound/core/timer.c:516
   snd_timer_start1+0x4d4/0x800 sound/core/timer.c:578
   snd_timer_start sound/core/timer.c:697 [inline]
   snd_timer_start sound/core/timer.c:690 [inline]
   snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1985
   __snd_timer_user_ioctl.isra.0+0xda8/0x2490 sound/core/timer.c:2108
   snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:874 [inline]
   __se_sys_ioctl fs/ioctl.c:860 [inline]
   __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x44/0xae


stack backtrace:
CPU: 0 PID: 7781 Comm: syz-executor.2 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_bad_irq_dependency kernel/locking/lockdep.c:2580 [inline]
 check_irq_usage.cold+0x4c1/0x6b0 kernel/locking/lockdep.c:2819
 check_prev_add kernel/locking/lockdep.c:3070 [inline]
 check_prevs_add kernel/locking/lockdep.c:3189 [inline]
 validate_chain kernel/locking/lockdep.c:3804 [inline]
 __lock_acquire+0x2a1f/0x54a0 kernel/locking/lockdep.c:5030
 lock_acquire kernel/locking/lockdep.c:5640 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605
 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline]
 _raw_read_lock_irqsave+0x70/0x90 kernel/locking/spinlock.c:236
 kill_fasync_rcu fs/fcntl.c:1014 [inline]
 kill_fasync fs/fcntl.c:1035 [inline]
 kill_fasync+0x136/0x470 fs/fcntl.c:1028
 snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1387
 snd_timer_notify1+0x11c/0x3b0 sound/core/timer.c:516
 snd_timer_start1+0x4d4/0x800 sound/core/timer.c:578
 snd_timer_start sound/core/timer.c:697 [inline]
 snd_timer_start sound/core/timer.c:690 [inline]
 snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1985
 __snd_timer_user_ioctl.isra.0+0xda8/0x2490 sound/core/timer.c:2108
 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f0ed92cbae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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:00007f0ed6841188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0ed93def60 RCX: 00007f0ed92cbae9
RDX: 0000000000000000 RSI: 00000000000054a0 RDI: 0000000000000003
RBP: 00007f0ed9325f25 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd5c4b9a0f R14: 00007f0ed6841300 R15: 0000000000022000
 </TASK>

Crashes (119):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/11/08 11:14 upstream 6b75d88fa81b 4c1be0be .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/11/07 11:51 upstream b5013d084e03 4c1be0be .config console log report info ci-upstream-kasan-gce possible deadlock in snd_timer_notify
2021/11/06 21:58 upstream d4439a1189f9 4c1be0be .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/11/05 06:55 upstream d4439a1189f9 4c1be0be .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/11/04 17:51 upstream 7ddb58cb0eca 4c1be0be .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/11/03 15:10 upstream dcd68326d29b 4c1be0be .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/11/02 18:18 upstream bfc484fe6abb 17f3edd2 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/11/02 12:56 upstream bfc484fe6abb 098b5d53 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/11/01 01:55 upstream 8bb7eca972ad 098b5d53 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/11/01 00:54 upstream 8bb7eca972ad 098b5d53 .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/30 18:58 upstream 119c85055d86 098b5d53 .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/29 06:28 upstream f25a5481af12 2353a3ec .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/28 23:02 upstream 411a44c24a56 be531bb4 .config console log report info ci-upstream-kasan-gce possible deadlock in snd_timer_notify
2021/10/28 11:15 upstream 1fc596a56b33 be531bb4 .config console log report info ci-upstream-kasan-gce possible deadlock in snd_timer_notify
2021/10/28 04:41 upstream 1fc596a56b33 be531bb4 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/10/27 14:15 upstream d25f27432f80 373bf66b .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/27 12:34 upstream d25f27432f80 373bf66b .config console log report info ci-upstream-kasan-gce possible deadlock in snd_timer_notify
2021/10/26 15:10 upstream 3906fe9bb7f1 d50eb50a .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/26 14:05 upstream 3906fe9bb7f1 d50eb50a .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/26 01:56 upstream c2b43854aad9 c1132b49 .config console log report info ci-upstream-kasan-gce possible deadlock in snd_timer_notify
2021/10/26 00:02 upstream c2b43854aad9 c1132b49 .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/25 04:50 upstream 87066fdd2e30 4f0000ee .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/22 19:50 upstream 64222515138e 282f03fb .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/22 04:52 upstream 2f111a6fd5b5 55f90bc6 .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/21 15:37 upstream 2f111a6fd5b5 c5cb7da8 .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/21 14:32 upstream 2f111a6fd5b5 c5cb7da8 .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/21 12:12 upstream 2f111a6fd5b5 f111d03b .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/20 19:36 upstream 8e37395c3a5d 418a00eb .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/20 11:15 upstream d9abdee5fd5a 418a00eb .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/10/19 19:30 upstream d9abdee5fd5a 466b7db1 .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/18 23:37 upstream 519d81956ee2 24dc29db .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/17 11:56 upstream d999ade1cc86 0c5d9412 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/10/17 10:51 upstream d999ade1cc86 0c5d9412 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/10/16 21:37 upstream 304040fb4909 0c5d9412 .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/16 05:26 upstream 8fe31e0995f0 0c5d9412 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in snd_timer_notify
2021/10/15 12:28 upstream ec681c53f8d2 0c5d9412 .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/15 10:05 upstream ec681c53f8d2 0c5d9412 .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/14 21:43 upstream 26d657410983 7aa5fe41 .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/13 21:33 upstream 348949d9a444 5462d470 .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/12 06:32 upstream fa5878760579 838e7e2c .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/11 12:46 upstream 64570fbc14f8 838e7e2c .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/11 07:28 upstream 64570fbc14f8 838e7e2c .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/09 17:31 upstream 717478d89fe2 838e7e2c .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/08 22:51 upstream 5d6ab0bb408f efe0f24d .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/08 08:20 upstream 1da38549dd64 efe0f24d .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/08 02:32 upstream 4a16df549d23 efe0f24d .config console log report info ci-upstream-kasan-gce possible deadlock in snd_timer_notify
2021/10/07 20:44 upstream 4a16df549d23 efe0f24d .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in snd_timer_notify
2021/10/07 17:21 upstream 5af4055fa813 efe0f24d .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/07 10:43 upstream 5af4055fa813 62ee0987 .config console log report info ci-upstream-kasan-gce possible deadlock in snd_timer_notify
2021/07/24 19:14 upstream f0fddcec6b62 4d1b57d4 .config console log report info ci-upstream-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/21 09:59 linux-next 3196a52aff93 f111d03b .config console log report info ci-upstream-linux-next-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/20 23:44 linux-next 51dba6e335ff f111d03b .config console log report info ci-upstream-linux-next-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/18 11:28 linux-next 60e8840126bd 0c5d9412 .config console log report info ci-upstream-linux-next-kasan-gce-root possible deadlock in snd_timer_notify
2021/10/07 16:11 linux-next f8dc23b3dc0c efe0f24d .config console log report info ci-upstream-linux-next-kasan-gce-root possible deadlock in snd_timer_notify
* Struck through repros no longer work on HEAD.