syzbot


possible deadlock in input_event

Status: upstream: reported on 2025/06/30 21:29
Reported-by: syzbot+1b21cb06d4cb066076cd@syzkaller.appspotmail.com
First crash: 12d, last: 12d
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in input_event origin:upstream missing-backport 4 C done 392 2d21h 750d 0/3 upstream: reported C repro on 2023/06/23 12:11
upstream possible deadlock in input_event (2) fs 4 C inconclusive 5993 3h28m 1340d 0/29 upstream: reported C repro on 2021/11/10 17:01
upstream possible deadlock in input_event 4 C done 2740 1341d 1645d 0/29 closed as dup on 2021/07/07 07:31
linux-5.15 possible deadlock in input_event missing-backport origin:upstream 4 C 392 3d16h 726d 0/3 upstream: reported C repro on 2023/07/17 14:44

Sample crash report:
=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
6.6.95-syzkaller #0 Not tainted
-----------------------------------------------------
syz.6.878/9226 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff8880318c0558 (&new->fa_lock){....}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:990 [inline]
ffff8880318c0558 (&new->fa_lock){....}-{2:2}, at: kill_fasync+0x192/0x4b0 fs/fcntl.c:1011

and this task is already holding:
ffff888059bcf028 (&client->buffer_lock){....}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff888059bcf028 (&client->buffer_lock){....}-{2:2}, at: evdev_pass_values+0xcb/0xab0 drivers/input/evdev.c:261
which would create a new lock dependency:
 (&client->buffer_lock){....}-{2:2} -> (&new->fa_lock){....}-{2:2}

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

... which became HARDIRQ-irq-safe at:
  lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
  input_event+0x7a/0xc0 drivers/input/input.c:434
  input_report_key include/linux/input.h:425 [inline]
  psmouse_report_standard_buttons drivers/input/mouse/psmouse-base.c:128 [inline]
  psmouse_report_standard_packet+0x53/0x200 drivers/input/mouse/psmouse-base.c:146
  psmouse_process_byte+0x478/0x670 drivers/input/mouse/psmouse-base.c:237
  psmouse_handle_byte+0x43/0x490 drivers/input/mouse/psmouse-base.c:279
  ps2_interrupt+0x164/0x980 drivers/input/serio/libps2.c:613
  serio_interrupt+0x8b/0x130 drivers/input/serio/serio.c:998
  i8042_interrupt+0x394/0x730 drivers/input/serio/i8042.c:610
  __handle_irq_event_percpu+0x276/0x930 kernel/irq/handle.c:158
  handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
  handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
  handle_edge_irq+0x247/0xb30 kernel/irq/chip.c:831
  generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
  handle_irq arch/x86/kernel/irq.c:240 [inline]
  __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
  common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
  asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
  __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
  _raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194
  spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
  i8042_command drivers/input/serio/i8042.c:360 [inline]
  i8042_aux_write+0x109/0x170 drivers/input/serio/i8042.c:395
  serio_write include/linux/serio.h:126 [inline]
  ps2_do_sendbyte+0x1ff/0x6d0 drivers/input/serio/libps2.c:58
  ps2_sendbyte+0x5f/0x120 drivers/input/serio/libps2.c:113
  cypress_ps2_sendbyte drivers/input/mouse/cypress_ps2.c:42 [inline]
  cypress_ps2_read_cmd_status drivers/input/mouse/cypress_ps2.c:116 [inline]
  cypress_send_ext_cmd+0x23d/0x920 drivers/input/mouse/cypress_ps2.c:189
  cypress_detect+0x8d/0x190 drivers/input/mouse/cypress_ps2.c:205
  psmouse_do_detect drivers/input/mouse/psmouse-base.c:1006 [inline]
  psmouse_try_protocol drivers/input/mouse/psmouse-base.c:1020 [inline]
  psmouse_extensions+0x467/0xbe0 drivers/input/mouse/psmouse-base.c:1143
  psmouse_switch_protocol+0xdc/0x610 drivers/input/mouse/psmouse-base.c:1537
  psmouse_connect+0x89f/0x1470 drivers/input/mouse/psmouse-base.c:1626
  serio_connect_driver drivers/input/serio/serio.c:44 [inline]
  serio_driver_probe+0x7a/0xa0 drivers/input/serio/serio.c:775
  call_driver_probe drivers/base/dd.c:-1 [inline]
  really_probe+0x25b/0xb40 drivers/base/dd.c:658
  __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
  driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
  __driver_attach+0x44e/0x6f0 drivers/base/dd.c:1216
  bus_for_each_dev+0x22d/0x2a0 drivers/base/bus.c:370
  serio_attach_driver drivers/input/serio/serio.c:804 [inline]
  serio_handle_event+0x1a2/0x860 drivers/input/serio/serio.c:224
  process_one_work kernel/workqueue.c:2634 [inline]
  process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
  worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
  kthread+0x2fa/0x390 kernel/kthread.c:388
  ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

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

... which became HARDIRQ-irq-unsafe at:
...
  lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
  __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
  _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
  do_wait+0x294/0xaf0 kernel/exit.c:1607
  kernel_wait+0xac/0x170 kernel/exit.c:1797
  call_usermodehelper_exec_sync kernel/umh.c:137 [inline]
  call_usermodehelper_exec_work+0xb9/0x220 kernel/umh.c:164
  process_one_work kernel/workqueue.c:2634 [inline]
  process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
  worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
  kthread+0x2fa/0x390 kernel/kthread.c:388
  ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

other info that might help us debug this:

Chain exists of:
  &dev->event_lock#2 --> &client->buffer_lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(&dev->event_lock#2);
                               lock(&client->buffer_lock);
  <Interrupt>
    lock(&dev->event_lock#2);

 *** DEADLOCK ***

7 locks held by syz.6.878/9226:
 #0: ffff8880263c0110 (&evdev->mutex){+.+.}-{3:3}, at: evdev_write+0x17b/0x470 drivers/input/evdev.c:513
 #1: ffff888026222230 (&dev->event_lock#2){-...}-{2:2}, at: input_inject_event+0xab/0x320 drivers/input/input.c:460
 #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: input_inject_event+0xbc/0x320 drivers/input/input.c:462
 #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: input_pass_values+0xa3/0x1300 drivers/input/input.c:153
 #4: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #4: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #4: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: evdev_events+0x79/0x330 drivers/input/evdev.c:298
 #5: ffff888059bcf028 (&client->buffer_lock){....}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #5: ffff888059bcf028 (&client->buffer_lock){....}-{2:2}, at: evdev_pass_values+0xcb/0xab0 drivers/input/evdev.c:261
 #6: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #6: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #6: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: kill_fasync+0x53/0x4b0 fs/fcntl.c:1010

the dependencies between HARDIRQ-irq-safe lock and the holding lock:
 -> (&dev->event_lock#2){-...}-{2:2} {
    IN-HARDIRQ-W at:
                      lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                      __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                      _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
                      input_event+0x7a/0xc0 drivers/input/input.c:434
                      input_report_key include/linux/input.h:425 [inline]
                      psmouse_report_standard_buttons drivers/input/mouse/psmouse-base.c:128 [inline]
                      psmouse_report_standard_packet+0x53/0x200 drivers/input/mouse/psmouse-base.c:146
                      psmouse_process_byte+0x478/0x670 drivers/input/mouse/psmouse-base.c:237
                      psmouse_handle_byte+0x43/0x490 drivers/input/mouse/psmouse-base.c:279
                      ps2_interrupt+0x164/0x980 drivers/input/serio/libps2.c:613
                      serio_interrupt+0x8b/0x130 drivers/input/serio/serio.c:998
                      i8042_interrupt+0x394/0x730 drivers/input/serio/i8042.c:610
                      __handle_irq_event_percpu+0x276/0x930 kernel/irq/handle.c:158
                      handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
                      handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
                      handle_edge_irq+0x247/0xb30 kernel/irq/chip.c:831
                      generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
                      handle_irq arch/x86/kernel/irq.c:240 [inline]
                      __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
                      common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
                      asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
                      __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
                      _raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194
                      spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
                      i8042_command drivers/input/serio/i8042.c:360 [inline]
                      i8042_aux_write+0x109/0x170 drivers/input/serio/i8042.c:395
                      serio_write include/linux/serio.h:126 [inline]
                      ps2_do_sendbyte+0x1ff/0x6d0 drivers/input/serio/libps2.c:58
                      ps2_sendbyte+0x5f/0x120 drivers/input/serio/libps2.c:113
                      cypress_ps2_sendbyte drivers/input/mouse/cypress_ps2.c:42 [inline]
                      cypress_ps2_read_cmd_status drivers/input/mouse/cypress_ps2.c:116 [inline]
                      cypress_send_ext_cmd+0x23d/0x920 drivers/input/mouse/cypress_ps2.c:189
                      cypress_detect+0x8d/0x190 drivers/input/mouse/cypress_ps2.c:205
                      psmouse_do_detect drivers/input/mouse/psmouse-base.c:1006 [inline]
                      psmouse_try_protocol drivers/input/mouse/psmouse-base.c:1020 [inline]
                      psmouse_extensions+0x467/0xbe0 drivers/input/mouse/psmouse-base.c:1143
                      psmouse_switch_protocol+0xdc/0x610 drivers/input/mouse/psmouse-base.c:1537
                      psmouse_connect+0x89f/0x1470 drivers/input/mouse/psmouse-base.c:1626
                      serio_connect_driver drivers/input/serio/serio.c:44 [inline]
                      serio_driver_probe+0x7a/0xa0 drivers/input/serio/serio.c:775
                      call_driver_probe drivers/base/dd.c:-1 [inline]
                      really_probe+0x25b/0xb40 drivers/base/dd.c:658
                      __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
                      driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
                      __driver_attach+0x44e/0x6f0 drivers/base/dd.c:1216
                      bus_for_each_dev+0x22d/0x2a0 drivers/base/bus.c:370
                      serio_attach_driver drivers/input/serio/serio.c:804 [inline]
                      serio_handle_event+0x1a2/0x860 drivers/input/serio/serio.c:224
                      process_one_work kernel/workqueue.c:2634 [inline]
                      process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
                      worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
                      kthread+0x2fa/0x390 kernel/kthread.c:388
                      ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
                      ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
    INITIAL USE at:
                     lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                     __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                     _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
                     input_inject_event+0xab/0x320 drivers/input/input.c:460
                     led_trigger_event+0x133/0x210 drivers/leds/led-triggers.c:393
                     kbd_led_trigger_activate+0xbd/0x100 drivers/tty/vt/keyboard.c:1036
                     led_trigger_set+0x524/0x940 drivers/leds/led-triggers.c:212
                     led_trigger_set_default+0x1a0/0x1e0 drivers/leds/led-triggers.c:276
                     led_classdev_register_ext+0x6e9/0x940 drivers/leds/led-class.c:562
                     led_classdev_register include/linux/leds.h:279 [inline]
                     input_leds_connect+0x4eb/0x6b0 drivers/input/input-leds.c:139
                     input_attach_handler drivers/input/input.c:1064 [inline]
                     input_register_device+0xcdc/0x1070 drivers/input/input.c:2470
                     atkbd_connect+0x6fb/0x9a0 drivers/input/keyboard/atkbd.c:1341
                     serio_connect_driver drivers/input/serio/serio.c:44 [inline]
                     serio_driver_probe+0x7a/0xa0 drivers/input/serio/serio.c:775
                     call_driver_probe drivers/base/dd.c:-1 [inline]
                     really_probe+0x25b/0xb40 drivers/base/dd.c:658
                     __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
                     driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
                     __driver_attach+0x44e/0x6f0 drivers/base/dd.c:1216
                     bus_for_each_dev+0x22d/0x2a0 drivers/base/bus.c:370
                     serio_attach_driver drivers/input/serio/serio.c:804 [inline]
                     serio_handle_event+0x1a2/0x860 drivers/input/serio/serio.c:224
                     process_one_work kernel/workqueue.c:2634 [inline]
                     process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
                     worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
                     kthread+0x2fa/0x390 kernel/kthread.c:388
                     ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
                     ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
  }
  ... key      at: [<ffffffff971f0960>] input_allocate_device.__key.5+0x0/0x20
-> (&client->buffer_lock){....}-{2:2} {
   INITIAL USE at:
                   lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
                   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                   spin_lock include/linux/spinlock.h:351 [inline]
                   evdev_pass_values+0xcb/0xab0 drivers/input/evdev.c:261
                   evdev_events+0x1d8/0x330 drivers/input/evdev.c:306
                   input_to_handler drivers/input/input.c:129 [inline]
                   input_pass_values+0x907/0x1300 drivers/input/input.c:161
                   input_event_dispose+0x346/0x6c0 drivers/input/input.c:378
                   input_inject_event+0x1f9/0x320 drivers/input/input.c:465
                   evdev_write+0x32a/0x470 drivers/input/evdev.c:530
                   vfs_write+0x288/0x940 fs/read_write.c:582
                   ksys_write+0x147/0x250 fs/read_write.c:637
                   do_syscall_x64 arch/x86/entry/common.c:51 [inline]
                   do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
                   entry_SYSCALL_64_after_hwframe+0x68/0xd2
 }
 ... key      at: [<ffffffff971f0c00>] evdev_open.__key.28+0x0/0x20
 ... acquired at:
   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
   spin_lock include/linux/spinlock.h:351 [inline]
   evdev_pass_values+0xcb/0xab0 drivers/input/evdev.c:261
   evdev_events+0x1d8/0x330 drivers/input/evdev.c:306
   input_to_handler drivers/input/input.c:129 [inline]
   input_pass_values+0x907/0x1300 drivers/input/input.c:161
   input_event_dispose+0x346/0x6c0 drivers/input/input.c:378
   input_inject_event+0x1f9/0x320 drivers/input/input.c:465
   evdev_write+0x32a/0x470 drivers/input/evdev.c:530
   vfs_write+0x288/0x940 fs/read_write.c:582
   ksys_write+0x147/0x250 fs/read_write.c:637
   do_syscall_x64 arch/x86/entry/common.c:51 [inline]
   do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
   entry_SYSCALL_64_after_hwframe+0x68/0xd2


the dependencies between the lock to be acquired
 and HARDIRQ-irq-unsafe lock:
  -> (tasklist_lock){.+.+}-{2:2} {
     HARDIRQ-ON-R at:
                        lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                        __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                        _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                        do_wait+0x294/0xaf0 kernel/exit.c:1607
                        kernel_wait+0xac/0x170 kernel/exit.c:1797
                        call_usermodehelper_exec_sync kernel/umh.c:137 [inline]
                        call_usermodehelper_exec_work+0xb9/0x220 kernel/umh.c:164
                        process_one_work kernel/workqueue.c:2634 [inline]
                        process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
                        worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
                        kthread+0x2fa/0x390 kernel/kthread.c:388
                        ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
                        ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
     SOFTIRQ-ON-R at:
                        lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                        __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                        _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                        do_wait+0x294/0xaf0 kernel/exit.c:1607
                        kernel_wait+0xac/0x170 kernel/exit.c:1797
                        call_usermodehelper_exec_sync kernel/umh.c:137 [inline]
                        call_usermodehelper_exec_work+0xb9/0x220 kernel/umh.c:164
                        process_one_work kernel/workqueue.c:2634 [inline]
                        process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
                        worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
                        kthread+0x2fa/0x390 kernel/kthread.c:388
                        ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
                        ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
     INITIAL USE at:
                       lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                       __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                       _raw_write_lock_irq+0xa3/0xe0 kernel/locking/spinlock.c:326
                       copy_process+0x225d/0x3d70 kernel/fork.c:2631
                       kernel_clone+0x21b/0x840 kernel/fork.c:2914
                       user_mode_thread+0xde/0x130 kernel/fork.c:2992
                       rest_init+0x27/0x300 init/main.c:697
                       arch_call_rest_init+0xe/0x10 init/main.c:829
                       start_kernel+0x459/0x4e0 init/main.c:1074
                       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
                       copy_bootdata+0x0/0xe0 arch/x86/kernel/head64.c:536
                       secondary_startup_64_no_verify+0x179/0x17b
     INITIAL READ USE at:
                            lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                            __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                            _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                            do_wait+0x294/0xaf0 kernel/exit.c:1607
                            kernel_wait+0xac/0x170 kernel/exit.c:1797
                            call_usermodehelper_exec_sync kernel/umh.c:137 [inline]
                            call_usermodehelper_exec_work+0xb9/0x220 kernel/umh.c:164
                            process_one_work kernel/workqueue.c:2634 [inline]
                            process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
                            worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
                            kthread+0x2fa/0x390 kernel/kthread.c:388
                            ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
                            ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
   }
   ... key      at: [<ffffffff8ca0a058>] tasklist_lock+0x18/0x40
   ... acquired at:
   __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
   _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
   send_sigio+0xf9/0x360 fs/fcntl.c:786
   kill_fasync_rcu fs/fcntl.c:997 [inline]
   kill_fasync+0x228/0x4b0 fs/fcntl.c:1011
   sock_wake_async+0x137/0x160 net/socket.c:-1
   sk_wake_async+0x184/0x280 include/net/sock.h:2565
   unix_release_sock+0x6b2/0xc80 net/unix/af_unix.c:637
   unix_release+0x8c/0xc0 net/unix/af_unix.c:1048
   __sock_release net/socket.c:659 [inline]
   sock_close+0xbd/0x230 net/socket.c:1421
   __fput+0x234/0x970 fs/file_table.c:384
   task_work_run+0x1ce/0x250 kernel/task_work.c:239
   get_signal+0x1235/0x1400 kernel/signal.c:2678
   arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
   exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
   exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
   __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
   syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
   do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
   entry_SYSCALL_64_after_hwframe+0x68/0xd2

 -> (&f->f_owner.lock){....}-{2:2} {
    INITIAL USE at:
                     lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                     _raw_write_lock_irq+0xa3/0xe0 kernel/locking/spinlock.c:326
                     __f_setown+0x3b/0x330 fs/fcntl.c:92
                     __tty_fasync drivers/tty/tty_io.c:2238 [inline]
                     tty_fasync+0x258/0x340 drivers/tty/tty_io.c:2253
                     setfl fs/fcntl.c:74 [inline]
                     do_fcntl+0xd4f/0x1380 fs/fcntl.c:334
                     __do_sys_fcntl fs/fcntl.c:448 [inline]
                     __se_sys_fcntl+0xc9/0x1a0 fs/fcntl.c:433
                     do_syscall_x64 arch/x86/entry/common.c:51 [inline]
                     do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
                     entry_SYSCALL_64_after_hwframe+0x68/0xd2
    INITIAL READ USE at:
                          lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                          __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
                          _raw_read_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:236
                          send_sigurg+0x29/0x3c0 fs/fcntl.c:811
                          sk_send_sigurg+0x6f/0xc0 net/core/sock.c:3387
                          queue_oob+0x4b5/0x5d0 net/unix/af_unix.c:2159
                          unix_stream_sendmsg+0xaa2/0xba0 net/unix/af_unix.c:2278
                          sock_sendmsg_nosec net/socket.c:730 [inline]
                          __sock_sendmsg net/socket.c:745 [inline]
                          ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
                          ___sys_sendmsg+0x220/0x290 net/socket.c:2649
                          __sys_sendmsg net/socket.c:2678 [inline]
                          __do_sys_sendmsg net/socket.c:2687 [inline]
                          __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
                          do_syscall_x64 arch/x86/entry/common.c:51 [inline]
                          do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
                          entry_SYSCALL_64_after_hwframe+0x68/0xd2
  }
  ... key      at: [<ffffffff96ef7200>] init_file.__key+0x0/0x20
  ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
   _raw_read_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:236
   send_sigio+0x33/0x360 fs/fcntl.c:772
   kill_fasync_rcu fs/fcntl.c:997 [inline]
   kill_fasync+0x228/0x4b0 fs/fcntl.c:1011
   sock_wake_async+0x137/0x160 net/socket.c:-1
   sk_wake_async+0x184/0x280 include/net/sock.h:2565
   unix_release_sock+0x6b2/0xc80 net/unix/af_unix.c:637
   unix_release+0x8c/0xc0 net/unix/af_unix.c:1048
   __sock_release net/socket.c:659 [inline]
   sock_close+0xbd/0x230 net/socket.c:1421
   __fput+0x234/0x970 fs/file_table.c:384
   task_work_run+0x1ce/0x250 kernel/task_work.c:239
   get_signal+0x1235/0x1400 kernel/signal.c:2678
   arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
   exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
   exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
   __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
   syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
   do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
   entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> (&new->fa_lock){....}-{2:2} {
   INITIAL USE at:
                   lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                   _raw_write_lock_irq+0xa3/0xe0 kernel/locking/spinlock.c:326
                   fasync_remove_entry+0xf4/0x1c0 fs/fcntl.c:867
                   __tty_fasync drivers/tty/tty_io.c:2220 [inline]
                   tty_fasync+0xfb/0x340 drivers/tty/tty_io.c:2253
                   __fput+0x7f3/0x970 fs/file_table.c:381
                   task_work_run+0x1ce/0x250 kernel/task_work.c:239
                   resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
                   exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
                   exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
                   __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
                   syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
                   do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
                   entry_SYSCALL_64_after_hwframe+0x68/0xd2
   INITIAL READ USE at:
                        lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
                        __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
                        _raw_read_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:236
                        kill_fasync_rcu fs/fcntl.c:990 [inline]
                        kill_fasync+0x192/0x4b0 fs/fcntl.c:1011
                        sock_wake_async+0x137/0x160 net/socket.c:-1
                        sk_wake_async+0x184/0x280 include/net/sock.h:2565
                        unix_release_sock+0x6b2/0xc80 net/unix/af_unix.c:637
                        unix_release+0x8c/0xc0 net/unix/af_unix.c:1048
                        __sock_release net/socket.c:659 [inline]
                        sock_close+0xbd/0x230 net/socket.c:1421
                        __fput+0x234/0x970 fs/file_table.c:384
                        task_work_run+0x1ce/0x250 kernel/task_work.c:239
                        get_signal+0x1235/0x1400 kernel/signal.c:2678
                        arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
                        exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
                        exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
                        __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
                        syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
                        do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
                        entry_SYSCALL_64_after_hwframe+0x68/0xd2
 }
 ... key      at: [<ffffffff96ef7e80>] fasync_insert_entry.__key+0x0/0x20
 ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
   _raw_read_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:236
   kill_fasync_rcu fs/fcntl.c:990 [inline]
   kill_fasync+0x192/0x4b0 fs/fcntl.c:1011
   __pass_event drivers/input/evdev.c:240 [inline]
   evdev_pass_values+0x54b/0xab0 drivers/input/evdev.c:278
   evdev_events+0x1d8/0x330 drivers/input/evdev.c:306
   input_to_handler drivers/input/input.c:129 [inline]
   input_pass_values+0x907/0x1300 drivers/input/input.c:161
   input_event_dispose+0x346/0x6c0 drivers/input/input.c:378
   input_inject_event+0x1f9/0x320 drivers/input/input.c:465
   evdev_write+0x32a/0x470 drivers/input/evdev.c:530
   vfs_write+0x288/0x940 fs/read_write.c:582
   ksys_write+0x147/0x250 fs/read_write.c:637
   do_syscall_x64 arch/x86/entry/common.c:51 [inline]
   do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
   entry_SYSCALL_64_after_hwframe+0x68/0xd2


stack backtrace:
CPU: 0 PID: 9226 Comm: syz.6.878 Not tainted 6.6.95-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline]
 check_irq_usage kernel/locking/lockdep.c:2865 [inline]
 check_prev_add kernel/locking/lockdep.c:3138 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x678f/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
 _raw_read_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:236
 kill_fasync_rcu fs/fcntl.c:990 [inline]
 kill_fasync+0x192/0x4b0 fs/fcntl.c:1011
 __pass_event drivers/input/evdev.c:240 [inline]
 evdev_pass_values+0x54b/0xab0 drivers/input/evdev.c:278
 evdev_events+0x1d8/0x330 drivers/input/evdev.c:306
 input_to_handler drivers/input/input.c:129 [inline]
 input_pass_values+0x907/0x1300 drivers/input/input.c:161
 input_event_dispose+0x346/0x6c0 drivers/input/input.c:378
 input_inject_event+0x1f9/0x320 drivers/input/input.c:465
 evdev_write+0x32a/0x470 drivers/input/evdev.c:530
 vfs_write+0x288/0x940 fs/read_write.c:582
 ksys_write+0x147/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe7fcb8e929
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe7fd9e1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe7fcdb5fa0 RCX: 00007fe7fcb8e929
RDX: 0000000000002250 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 00007fe7fcc10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe7fcdb5fa0 R15: 00007ffc3dcc9868
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/30 21:29 linux-6.6.y 3f5b4c104b7d 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/06/30 21:29 linux-6.6.y 3f5b4c104b7d 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
* Struck through repros no longer work on HEAD.