===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 5.17.0-rc2-syzkaller-00060-g88808fbbead4 #0 Not tainted ----------------------------------------------------- syz-executor612/3594 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff8b80a098 (tasklist_lock){.+.+}-{2:2}, at: send_sigio+0xab/0x380 fs/fcntl.c:810 and this task is already holding: ffff888076825038 (&f->f_owner.lock){....}-{2:2}, at: send_sigio+0x24/0x380 fs/fcntl.c:796 which would create a new lock dependency: (&f->f_owner.lock){....}-{2:2} -> (tasklist_lock){.+.+}-{2:2} but this new dependency connects a HARDIRQ-irq-safe lock: (&timer->lock){-...}-{2:2} ... which became HARDIRQ-irq-safe at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] snd_hrtimer_callback+0x4f/0x3c0 sound/core/hrtimer.c:38 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline] snd_seq_cell_free+0x20a/0x410 sound/core/seq/seq_memory.c:202 snd_seq_dispatch_event+0x11e/0x580 sound/core/seq/seq_clientmgr.c:916 snd_seq_check_queue+0x173/0x440 sound/core/seq/seq_queue.c:268 snd_seq_enqueue_event+0x1ed/0x3e0 sound/core/seq/seq_queue.c:344 snd_seq_client_enqueue_event.constprop.0+0x230/0x440 sound/core/seq/seq_clientmgr.c:976 snd_seq_kernel_client_enqueue+0x191/0x1e0 sound/core/seq/seq_clientmgr.c:2298 insert_queue sound/core/seq/oss/seq_oss_rw.c:174 [inline] snd_seq_oss_write+0x5d7/0x780 sound/core/seq/oss/seq_oss_rw.c:135 odev_write+0x55/0x90 sound/core/seq/oss/seq_oss.c:168 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 HARDIRQ-irq-unsafe lock: (tasklist_lock){.+.+}-{2:2} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 do_wait+0x284/0xce0 kernel/exit.c:1518 kernel_wait+0x9c/0x150 kernel/exit.c:1708 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 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 --> &f->f_owner.lock --> tasklist_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(&timer->lock); lock(&f->f_owner.lock); lock(&timer->lock); *** DEADLOCK *** 5 locks held by syz-executor612/3594: #0: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: sock_def_readable+0x0/0x4e0 include/trace/events/sock.h:204 #1: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: rcu_read_unlock include/linux/rcupdate.h:723 [inline] #1: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: sock_def_readable+0x2aa/0x4e0 net/core/sock.c:3150 #2: ffffffff8bb83c20 (rcu_read_lock){....}-{1:2}, at: kill_fasync+0x41/0x470 fs/fcntl.c:1033 #3: ffff8880701ce0c0 (&new->fa_lock){....}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:1014 [inline] #3: ffff8880701ce0c0 (&new->fa_lock){....}-{2:2}, at: kill_fasync fs/fcntl.c:1035 [inline] #3: ffff8880701ce0c0 (&new->fa_lock){....}-{2:2}, at: kill_fasync+0x136/0x470 fs/fcntl.c:1028 #4: ffff888076825038 (&f->f_owner.lock){....}-{2:2}, at: send_sigio+0x24/0x380 fs/fcntl.c:796 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&timer->lock){-...}-{2:2} { IN-HARDIRQ-W at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] snd_hrtimer_callback+0x4f/0x3c0 sound/core/hrtimer.c:38 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline] snd_seq_cell_free+0x20a/0x410 sound/core/seq/seq_memory.c:202 snd_seq_dispatch_event+0x11e/0x580 sound/core/seq/seq_clientmgr.c:916 snd_seq_check_queue+0x173/0x440 sound/core/seq/seq_queue.c:268 snd_seq_enqueue_event+0x1ed/0x3e0 sound/core/seq/seq_queue.c:344 snd_seq_client_enqueue_event.constprop.0+0x230/0x440 sound/core/seq/seq_clientmgr.c:976 snd_seq_kernel_client_enqueue+0x191/0x1e0 sound/core/seq/seq_clientmgr.c:2298 insert_queue sound/core/seq/oss/seq_oss_rw.c:174 [inline] snd_seq_oss_write+0x5d7/0x780 sound/core/seq/oss/seq_oss_rw.c:135 odev_write+0x55/0x90 sound/core/seq/oss/seq_oss.c:168 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:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __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_resolution+0x55/0x100 sound/core/timer.c:489 initialize_timer+0x183/0x290 sound/core/seq/seq_timer.c:373 seq_timer_start sound/core/seq/seq_timer.c:391 [inline] snd_seq_timer_start+0x151/0x290 sound/core/seq/seq_timer.c:405 snd_seq_queue_process_event sound/core/seq/seq_queue.c:660 [inline] snd_seq_control_queue+0x872/0xaa0 sound/core/seq/seq_queue.c:721 snd_seq_deliver_single_event.constprop.0+0x42b/0x820 sound/core/seq/seq_clientmgr.c:640 snd_seq_deliver_event+0x4e7/0x970 sound/core/seq/seq_clientmgr.c:841 snd_seq_kernel_client_dispatch+0x145/0x180 sound/core/seq/seq_clientmgr.c:2339 send_timer_event.isra.0+0x10b/0x160 sound/core/seq/oss/seq_oss_timer.c:140 snd_seq_oss_timer_start+0x1c3/0x310 sound/core/seq/oss/seq_oss_timer.c:161 old_event sound/core/seq/oss/seq_oss_event.c:113 [inline] snd_seq_oss_process_event+0xda5/0x27d0 sound/core/seq/oss/seq_oss_event.c:88 insert_queue sound/core/seq/oss/seq_oss_rw.c:167 [inline] snd_seq_oss_write+0x227/0x780 sound/core/seq/oss/seq_oss_rw.c:135 odev_write+0x55/0x90 sound/core/seq/oss/seq_oss.c:168 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 } ... key at: [] __key.12+0x0/0x40 -> (&new->fa_lock){....}-{2:2} { INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [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:1386 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:696 [inline] snd_timer_start sound/core/timer.c:689 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1984 __snd_timer_user_ioctl.isra.0+0xda8/0x2490 sound/core/timer.c:2107 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2128 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: [] __key.0+0x0/0x40 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [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:1386 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:696 [inline] snd_timer_start sound/core/timer.c:689 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1984 __snd_timer_user_ioctl.isra.0+0xda8/0x2490 sound/core/timer.c:2107 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2128 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 -> (&f->f_owner.lock){....}-{2:2} { INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:326 f_modown+0x2a/0x390 fs/fcntl.c:91 __f_setown fs/fcntl.c:110 [inline] f_setown+0xd7/0x230 fs/fcntl.c:138 sock_ioctl+0x37e/0x640 net/socket.c:1182 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 INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x70/0x90 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 snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1386 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:696 [inline] snd_timer_start sound/core/timer.c:689 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1984 __snd_timer_user_ioctl.isra.0+0xda8/0x2490 sound/core/timer.c:2107 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2128 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: [] __key.5+0x0/0x40 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x70/0x90 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 snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1386 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:696 [inline] snd_timer_start sound/core/timer.c:689 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1984 __snd_timer_user_ioctl.isra.0+0xda8/0x2490 sound/core/timer.c:2107 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2128 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 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (tasklist_lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 do_wait+0x284/0xce0 kernel/exit.c:1518 kernel_wait+0x9c/0x150 kernel/exit.c:1708 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 SOFTIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 do_wait+0x284/0xce0 kernel/exit.c:1518 kernel_wait+0x9c/0x150 kernel/exit.c:1708 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:326 copy_process+0x47da/0x7300 kernel/fork.c:2284 kernel_clone+0xe7/0xab0 kernel/fork.c:2555 kernel_thread+0xb5/0xf0 kernel/fork.c:2607 rest_init+0x23/0x3e0 init/main.c:690 start_kernel+0x47a/0x49b init/main.c:1138 secondary_startup_64_no_verify+0xc3/0xcb INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 do_wait+0x284/0xce0 kernel/exit.c:1518 kernel_wait+0x9c/0x150 kernel/exit.c:1708 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_read_lock include/linux/rwlock_api_smp.h:150 [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:1372 sk_wake_async include/net/sock.h:2444 [inline] sk_wake_async include/net/sock.h:2440 [inline] sock_def_readable+0x349/0x4e0 net/core/sock.c:3149 unix_dgram_sendmsg+0xf30/0x1a10 net/unix/af_unix.c:2029 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x331/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmmsg+0x195/0x470 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579 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: 3594 Comm: syz-executor612 Not tainted 5.17.0-rc2-syzkaller-00060-g88808fbbead4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __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:2577 [inline] check_irq_usage.cold+0x4c1/0x6b0 kernel/locking/lockdep.c:2816 check_prev_add kernel/locking/lockdep.c:3067 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2a44/0x5470 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_read_lock include/linux/rwlock_api_smp.h:150 [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:1372 sk_wake_async include/net/sock.h:2444 [inline] sk_wake_async include/net/sock.h:2440 [inline] sock_def_readable+0x349/0x4e0 net/core/sock.c:3149 unix_dgram_sendmsg+0xf30/0x1a10 net/unix/af_unix.c:2029 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x331/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmmsg+0x195/0x470 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579 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: 0033:0x7fe4c19ec509 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe