===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected syzkaller #0 Tainted: G L ----------------------------------------------------- syz.7.3184/18691 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff888022f93d38 (&new->fa_lock){....}-{3:3}, at: kill_fasync_rcu fs/fcntl.c:1135 [inline] ffff888022f93d38 (&new->fa_lock){....}-{3:3}, at: kill_fasync+0x199/0x4d0 fs/fcntl.c:1159 and this task is already holding: ffff8880349b4440 (&tty->flow.lock){....}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:372 [inline] ffff8880349b4440 (&tty->flow.lock){....}-{3:3}, at: n_tty_ioctl_helper+0xe0/0x4d0 drivers/tty/tty_ioctl.c:956 which would create a new lock dependency: (&tty->flow.lock){....}-{3:3} -> (&new->fa_lock){....}-{3:3} but this new dependency connects a SOFTIRQ-irq-safe lock: (kbd_event_lock){..-.}-{3:3} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] class_spinlock_constructor include/linux/spinlock.h:587 [inline] kbd_event+0xd7/0x42f0 drivers/tty/vt/keyboard.c:1578 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2558 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x3e5/0x6b0 drivers/input/input.c:353 input_inject_event+0x1dc/0x330 drivers/input/input.c:424 kd_sound_helper+0x101/0x210 drivers/tty/vt/keyboard.c:257 input_handler_for_each_handle+0x101/0x1c0 drivers/input/input.c:2537 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 bytes_is_nonzero mm/kasan/generic.c:97 [inline] memory_is_nonzero mm/kasan/generic.c:115 [inline] memory_is_poisoned_n mm/kasan/generic.c:140 [inline] memory_is_poisoned mm/kasan/generic.c:172 [inline] check_region_inline mm/kasan/generic.c:191 [inline] kasan_check_range+0x8d/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:82 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:649 [inline] cpu_online include/linux/cpumask.h:1231 [inline] trace_contention_end+0x2e/0x140 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:655 [inline] __mutex_lock+0x30f/0x1550 kernel/locking/mutex.c:820 __unix_dgram_recvmsg+0x1e2/0xd60 net/unix/af_unix.c:2584 sock_recvmsg_nosec+0x10c/0x140 net/socket.c:1137 ____sys_recvmsg+0x3e3/0x4a0 net/socket.c:2916 ___sys_recvmsg+0x215/0x590 net/socket.c:2960 do_recvmmsg+0x334/0x800 net/socket.c:3055 __sys_recvmmsg net/socket.c:3129 [inline] __do_sys_recvmmsg net/socket.c:3152 [inline] __se_sys_recvmmsg net/socket.c:3145 [inline] __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3145 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f to a SOFTIRQ-irq-unsafe lock: (tasklist_lock){.+.+}-{3:3} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232 __do_wait+0xde/0x740 kernel/exit.c:1677 do_wait+0x1e7/0x510 kernel/exit.c:1721 kernel_wait+0xd6/0x1c0 kernel/exit.c:1897 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Chain exists of: kbd_event_lock --> &tty->flow.lock --> tasklist_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(kbd_event_lock); lock(&tty->flow.lock); lock(kbd_event_lock); *** DEADLOCK *** 4 locks held by syz.7.3184/18691: #0: ffff8880349b40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffff8880349b4440 (&tty->flow.lock){....}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:372 [inline] #1: ffff8880349b4440 (&tty->flow.lock){....}-{3:3}, at: n_tty_ioctl_helper+0xe0/0x4d0 drivers/tty/tty_ioctl.c:956 #2: ffff8880349b40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x90 drivers/tty/tty_ldisc.c:263 #3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: kill_fasync+0x53/0x4d0 fs/fcntl.c:1158 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (kbd_event_lock){..-.}-{3:3} { IN-SOFTIRQ-W at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] class_spinlock_constructor include/linux/spinlock.h:587 [inline] kbd_event+0xd7/0x42f0 drivers/tty/vt/keyboard.c:1578 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2558 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x3e5/0x6b0 drivers/input/input.c:353 input_inject_event+0x1dc/0x330 drivers/input/input.c:424 kd_sound_helper+0x101/0x210 drivers/tty/vt/keyboard.c:257 input_handler_for_each_handle+0x101/0x1c0 drivers/input/input.c:2537 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 bytes_is_nonzero mm/kasan/generic.c:97 [inline] memory_is_nonzero mm/kasan/generic.c:115 [inline] memory_is_poisoned_n mm/kasan/generic.c:140 [inline] memory_is_poisoned mm/kasan/generic.c:172 [inline] check_region_inline mm/kasan/generic.c:191 [inline] kasan_check_range+0x8d/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:82 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:649 [inline] cpu_online include/linux/cpumask.h:1231 [inline] trace_contention_end+0x2e/0x140 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:655 [inline] __mutex_lock+0x30f/0x1550 kernel/locking/mutex.c:820 __unix_dgram_recvmsg+0x1e2/0xd60 net/unix/af_unix.c:2584 sock_recvmsg_nosec+0x10c/0x140 net/socket.c:1137 ____sys_recvmsg+0x3e3/0x4a0 net/socket.c:2916 ___sys_recvmsg+0x215/0x590 net/socket.c:2960 do_recvmmsg+0x334/0x800 net/socket.c:3055 __sys_recvmmsg net/socket.c:3129 [inline] __do_sys_recvmmsg net/socket.c:3152 [inline] __se_sys_recvmmsg net/socket.c:3145 [inline] __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3145 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL USE at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 class_spinlock_irqsave_constructor include/linux/spinlock.h:619 [inline] vt_reset_unicode+0x2b/0x160 drivers/tty/vt/keyboard.c:2194 reset_vc+0x68/0x1b0 drivers/tty/vt/vt_ioctl.c:966 vc_init+0x70/0x4a0 drivers/tty/vt/vt.c:3823 con_init+0x377/0x6a0 drivers/tty/vt/vt.c:3889 console_init+0x10b/0x4a0 kernel/printk/printk.c:4407 start_kernel+0x230/0x3e0 init/main.c:1157 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 } ... key at: [] kbd_event_lock+0x18/0xa0 keyboard.c:-1 -> (&tty->flow.lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 class_spinlock_irqsave_constructor include/linux/spinlock.h:619 [inline] start_tty+0x1b/0x50 drivers/tty/tty_io.c:793 n_tty_set_termios+0xa7c/0x10a0 drivers/tty/n_tty.c:1848 tty_set_termios+0xdb3/0x1800 drivers/tty/tty_ioctl.c:348 set_termios+0x566/0x710 drivers/tty/tty_ioctl.c:516 tty_mode_ioctl+0x4a6/0x7d0 drivers/tty/tty_ioctl.c:-1 tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] alloc_tty_struct.__key.35+0x0/0x20 ... acquired at: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 class_spinlock_irqsave_constructor include/linux/spinlock.h:619 [inline] stop_tty+0x2f/0x140 drivers/tty/tty_io.c:765 kbd_keycode drivers/tty/vt/keyboard.c:1565 [inline] kbd_event+0x2f91/0x42f0 drivers/tty/vt/keyboard.c:1583 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2558 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342 input_inject_event+0x1dc/0x330 drivers/input/input.c:424 evdev_write+0x325/0x4c0 drivers/input/evdev.c:528 vfs_write+0x29a/0xb90 fs/read_write.c:686 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (tasklist_lock){.+.+}-{3:3} { HARDIRQ-ON-R at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232 __do_wait+0xde/0x740 kernel/exit.c:1677 do_wait+0x1e7/0x510 kernel/exit.c:1721 kernel_wait+0xd6/0x1c0 kernel/exit.c:1897 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 SOFTIRQ-ON-R at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232 __do_wait+0xde/0x740 kernel/exit.c:1677 do_wait+0x1e7/0x510 kernel/exit.c:1721 kernel_wait+0xd6/0x1c0 kernel/exit.c:1897 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INITIAL USE at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_write_lock_irq include/linux/rwlock_api_smp.h:213 [inline] _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:330 copy_process+0x2b4c/0x4440 kernel/fork.c:2411 kernel_clone+0x284/0x8f0 kernel/fork.c:2721 user_mode_thread+0x110/0x180 kernel/fork.c:2797 rest_init+0x23/0x300 init/main.c:727 start_kernel+0x38a/0x3e0 init/main.c:1220 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 INITIAL READ USE at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232 __do_wait+0xde/0x740 kernel/exit.c:1677 do_wait+0x1e7/0x510 kernel/exit.c:1721 kernel_wait+0xd6/0x1c0 kernel/exit.c:1897 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232 send_sigio+0x101/0x370 fs/fcntl.c:932 dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113 fsnotify_handle_event fs/notify/fsnotify.c:327 [inline] send_to_group fs/notify/fsnotify.c:375 [inline] fsnotify+0x1831/0x1ae0 fs/notify/fsnotify.c:592 fsnotify_name include/linux/fsnotify.h:55 [inline] fsnotify_dirent include/linux/fsnotify.h:61 [inline] fsnotify_create include/linux/fsnotify.h:323 [inline] open_last_lookups fs/namei.c:4614 [inline] path_openat+0x15c2/0x3860 fs/namei.c:4855 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&f_owner->lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_write_lock_irq include/linux/rwlock_api_smp.h:213 [inline] _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:330 __f_setown+0x67/0x370 fs/fcntl.c:136 fcntl_dirnotify+0x3f9/0x6a0 fs/notify/dnotify/dnotify.c:369 do_fcntl+0x77e/0x1a20 fs/fcntl.c:538 __do_sys_fcntl fs/fcntl.c:602 [inline] __se_sys_fcntl+0xc8/0x150 fs/fcntl.c:587 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240 send_sigio+0x38/0x370 fs/fcntl.c:918 dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113 fsnotify_handle_event fs/notify/fsnotify.c:301 [inline] send_to_group fs/notify/fsnotify.c:375 [inline] fsnotify+0x168e/0x1ae0 fs/notify/fsnotify.c:592 __fsnotify_parent+0x50d/0x620 fs/notify/fsnotify.c:238 fsnotify_parent include/linux/fsnotify.h:96 [inline] fsnotify_path include/linux/fsnotify.h:113 [inline] fsnotify_file include/linux/fsnotify.h:127 [inline] fsnotify_access include/linux/fsnotify.h:425 [inline] vfs_read+0x854/0xa70 fs/read_write.c:578 ksys_read+0x150/0x270 fs/read_write.c:717 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] file_f_owner_allocate.__key+0x0/0x20 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240 send_sigio+0x38/0x370 fs/fcntl.c:918 kill_fasync_rcu fs/fcntl.c:1144 [inline] kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159 lease_break_callback+0x26/0x30 fs/locks.c:577 __break_lease+0x81f/0x1ea0 fs/locks.c:1669 break_deleg include/linux/filelock.h:505 [inline] try_break_deleg include/linux/filelock.h:524 [inline] __vfs_setxattr_locked+0x204/0x2c0 fs/xattr.c:309 vfs_setxattr+0x163/0x360 fs/xattr.c:339 do_setxattr fs/xattr.c:654 [inline] file_setxattr+0x1d9/0x2b0 fs/xattr.c:664 path_setxattrat+0x3b0/0x440 fs/xattr.c:724 __do_sys_fsetxattr fs/xattr.c:774 [inline] __se_sys_fsetxattr fs/xattr.c:771 [inline] __x64_sys_fsetxattr+0xbc/0xe0 fs/xattr.c:771 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&new->fa_lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_write_lock_irq include/linux/rwlock_api_smp.h:213 [inline] _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:330 fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:1012 sock_fasync+0x85/0xf0 net/socket.c:1539 __fput+0x890/0xa60 fs/file_table.c:507 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11eb/0x1330 kernel/signal.c:2809 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240 kill_fasync_rcu fs/fcntl.c:1135 [inline] kill_fasync+0x199/0x4d0 fs/fcntl.c:1159 sock_wake_async+0x137/0x160 net/socket.c:-1 sk_wake_async_rcu include/net/sock.h:2593 [inline] sock_def_error_report+0x332/0x390 net/core/sock.c:3601 sk_error_report+0x48/0x280 net/core/sock.c:348 unix_dgram_disconnected net/unix/af_unix.c:630 [inline] unix_dgram_connect+0x96b/0xc20 net/unix/af_unix.c:1584 __sys_connect_file net/socket.c:2148 [inline] __sys_connect+0x312/0x450 net/socket.c:2167 __do_sys_connect net/socket.c:2173 [inline] __se_sys_connect net/socket.c:2170 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2170 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] fasync_insert_entry.__key+0x0/0x20 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240 kill_fasync_rcu fs/fcntl.c:1135 [inline] kill_fasync+0x199/0x4d0 fs/fcntl.c:1159 tty_wakeup drivers/tty/tty_io.c:515 [inline] __start_tty+0x18c/0x220 drivers/tty/tty_io.c:777 n_tty_ioctl_helper+0x128/0x4d0 drivers/tty/tty_ioctl.c:959 tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f stack backtrace: CPU: 0 UID: 0 PID: 18691 Comm: syz.7.3184 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline] check_irq_usage kernel/locking/lockdep.c:2857 [inline] check_prev_add kernel/locking/lockdep.c:3169 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x2a94/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240 kill_fasync_rcu fs/fcntl.c:1135 [inline] kill_fasync+0x199/0x4d0 fs/fcntl.c:1159 tty_wakeup drivers/tty/tty_io.c:515 [inline] __start_tty+0x18c/0x220 drivers/tty/tty_io.c:777 n_tty_ioctl_helper+0x128/0x4d0 drivers/tty/tty_ioctl.c:959 tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0f1639cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0f17212028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0f16615fa0 RCX: 00007f0f1639cdd9 RDX: 0000000000000001 RSI: 000000000000540a RDI: 0000000000000009 RBP: 00007f0f16432d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0f16616038 R14: 00007f0f16615fa0 R15: 00007f0f1673fa48