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possible deadlock in input_event

Status: upstream: reported on 2025/06/30 21:29
Reported-by: syzbot+1b21cb06d4cb066076cd@syzkaller.appspotmail.com
First crash: 36d, last: 4d12h
▶ ▼ 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 412 5d08h 774d 0/3 upstream: reported C repro on 2023/06/23 12:11
upstream possible deadlock in input_event (2) fs 4 C inconclusive 6122 22m 1364d 0/29 upstream: reported C repro on 2021/11/10 17:01
upstream possible deadlock in input_event 4 C done 2740 1365d 1669d 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 396 17d 750d 0/3 upstream: reported C repro on 2023/07/17 14:44

Sample crash report:
=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
6.6.101-syzkaller #0 Not tainted
-----------------------------------------------------
syz.7.563/8309 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffffffff8ca0a058 (tasklist_lock){.+.+}-{2:2}, at: send_sigurg+0xf0/0x3c0 fs/fcntl.c:827

and this task is already holding:
ffff88805bd9c118 (&f->f_owner.lock){....}-{2:2}, at: send_sigurg+0x29/0x3c0 fs/fcntl.c:811
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:
 (&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
  lock_release+0x57c/0x8b0 kernel/locking/lockdep.c:5778
  up_write+0x2d/0x410 kernel/locking/rwsem.c:1625
  kernfs_add_one+0x235/0x6b0 fs/kernfs/dir.c:809
  __kernfs_create_file+0x237/0x2e0 fs/kernfs/file.c:1079
  sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:294
  sysfs_create_file_ns+0x129/0x1a0 fs/sysfs/file.c:355
  add_bind_files drivers/base/bus.c:591 [inline]
  bus_add_driver+0x454/0x640 drivers/base/bus.c:699
  driver_register+0x23a/0x310 drivers/base/driver.c:246
  usb_register_driver+0x206/0x3d0 drivers/usb/core/driver.c:1062
  do_one_initcall+0x1fd/0x750 init/main.c:1238
  do_initcall_level+0x137/0x1f0 init/main.c:1300
  do_initcalls+0x69/0xd0 init/main.c:1316
  kernel_init_freeable+0x3d2/0x570 init/main.c:1553
  kernel_init+0x1d/0x1c0 init/main.c:1443
  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 --> &f->f_owner.lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(&dev->event_lock#2);
                               lock(&f->f_owner.lock);
  <Interrupt>
    lock(&dev->event_lock#2);

 *** DEADLOCK ***

2 locks held by syz.7.563/8309:
 #0: ffff88807aa0ae78 (&u->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #0: ffff88807aa0ae78 (&u->lock){+.+.}-{2:2}, at: queue_oob+0x1cb/0x4e0 net/unix/af_unix.c:2190
 #1: ffff88805bd9c118 (&f->f_owner.lock){....}-{2:2}, at: send_sigurg+0x29/0x3c0 fs/fcntl.c:811

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
                          lock_release+0x57c/0x8b0 kernel/locking/lockdep.c:5778
                          up_write+0x2d/0x410 kernel/locking/rwsem.c:1625
                          kernfs_add_one+0x235/0x6b0 fs/kernfs/dir.c:809
                          __kernfs_create_file+0x237/0x2e0 fs/kernfs/file.c:1079
                          sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:294
                          sysfs_create_file_ns+0x129/0x1a0 fs/sysfs/file.c:355
                          add_bind_files drivers/base/bus.c:591 [inline]
                          bus_add_driver+0x454/0x640 drivers/base/bus.c:699
                          driver_register+0x23a/0x310 drivers/base/driver.c:246
                          usb_register_driver+0x206/0x3d0 drivers/usb/core/driver.c:1062
                          do_one_initcall+0x1fd/0x750 init/main.c:1238
                          do_initcall_level+0x137/0x1f0 init/main.c:1300
                          do_initcalls+0x69/0xd0 init/main.c:1316
                          kernel_init_freeable+0x3d2/0x570 init/main.c:1553
                          kernel_init+0x1d/0x1c0 init/main.c:1443
                          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:1342
                         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: [<ffffffff9720e600>] 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: [<ffffffff9720e8a0>] 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

 -> (&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_insert_entry+0xc8/0x270 fs/fcntl.c:914
                     lease_setup+0x86/0x110 fs/locks.c:537
                     generic_add_lease fs/locks.c:1815 [inline]
                     generic_setlease+0xe32/0x1270 fs/locks.c:1895
                     vfs_setlease fs/locks.c:1960 [inline]
                     do_fcntl_add_lease fs/locks.c:1981 [inline]
                     fcntl_setlease+0x268/0x340 fs/locks.c:2003
                     do_fcntl+0x1cb/0x1380 fs/fcntl.c:397
                     __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
                          kill_fasync_rcu fs/fcntl.c:990 [inline]
                          kill_fasync+0x192/0x4b0 fs/fcntl.c:1011
                          lease_break_callback+0x26/0x30 fs/locks.c:522
                          __break_lease+0x4a7/0x12c0 fs/locks.c:1537
                          break_lease include/linux/filelock.h:360 [inline]
                          do_dentry_open+0x823/0x1500 fs/open.c:920
                          do_open fs/namei.c:3632 [inline]
                          path_openat+0x274b/0x3190 fs/namei.c:3789
                          do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
                          do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
                          do_sys_open fs/open.c:1434 [inline]
                          __do_sys_openat fs/open.c:1450 [inline]
                          __se_sys_openat fs/open.c:1445 [inline]
                          __x64_sys_openat+0x139/0x160 fs/open.c:1445
                          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: [<ffffffff96f15ac0>] 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

-> (&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
                   generic_add_lease fs/locks.c:1815 [inline]
                   generic_setlease+0xe32/0x1270 fs/locks.c:1895
                   vfs_setlease fs/locks.c:1960 [inline]
                   do_fcntl_add_lease fs/locks.c:1981 [inline]
                   fcntl_setlease+0x268/0x340 fs/locks.c:2003
                   do_fcntl+0x1cb/0x1380 fs/fcntl.c:397
                   __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
                        tcp_check_urg+0x200/0x750 net/ipv4/tcp_input.c:5770
                        tcp_urg+0x161/0x3f0 net/ipv4/tcp_input.c:5811
                        tcp_rcv_established+0xa2e/0x1cf0 net/ipv4/tcp_input.c:6166
                        tcp_v4_do_rcv+0x4ed/0xb80 net/ipv4/tcp_ipv4.c:1734
                        sk_backlog_rcv include/net/sock.h:1123 [inline]
                        __release_sock+0x1bd/0x430 net/core/sock.c:2988
                        release_sock+0x5f/0x1c0 net/core/sock.c:3525
                        tcp_sendmsg+0x39/0x50 net/ipv4/tcp.c:1345
                        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_sendmmsg+0x275/0x4a0 net/socket.c:2735
                        __do_sys_sendmmsg net/socket.c:2764 [inline]
                        __se_sys_sendmmsg net/socket.c:2761 [inline]
                        __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2761
                        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: [<ffffffff96f14e40>] 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
   lease_break_callback+0x26/0x30 fs/locks.c:522
   __break_lease+0x4a7/0x12c0 fs/locks.c:1537
   break_lease include/linux/filelock.h:360 [inline]
   do_dentry_open+0x823/0x1500 fs/open.c:920
   do_open fs/namei.c:3632 [inline]
   path_openat+0x274b/0x3190 fs/namei.c:3789
   do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
   do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
   do_sys_open fs/open.c:1434 [inline]
   __do_sys_openat fs/open.c:1450 [inline]
   __se_sys_openat fs/open.c:1445 [inline]
   __x64_sys_openat+0x139/0x160 fs/open.c:1445
   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_sigurg+0xf0/0x3c0 fs/fcntl.c:827
   sk_send_sigurg+0x6f/0xc0 net/core/sock.c:3387
   queue_oob+0x3d7/0x4e0 net/unix/af_unix.c:2207
   unix_stream_sendmsg+0xaa2/0xba0 net/unix/af_unix.c:2326
   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_sendmmsg+0x275/0x4a0 net/socket.c:2735
   __do_sys_sendmmsg net/socket.c:2764 [inline]
   __se_sys_sendmmsg net/socket.c:2761 [inline]
   __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2761
   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: 8309 Comm: syz.7.563 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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 include/linux/rwlock_api_smp.h:150 [inline]
 _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
 send_sigurg+0xf0/0x3c0 fs/fcntl.c:827
 sk_send_sigurg+0x6f/0xc0 net/core/sock.c:3387
 queue_oob+0x3d7/0x4e0 net/unix/af_unix.c:2207
 unix_stream_sendmsg+0xaa2/0xba0 net/unix/af_unix.c:2326
 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_sendmmsg+0x275/0x4a0 net/socket.c:2735
 __do_sys_sendmmsg net/socket.c:2764 [inline]
 __se_sys_sendmmsg net/socket.c:2761 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2761
 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: 0033:0x7f78a8f8eb69
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:00007f78a9d75038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f78a91b5fa0 RCX: 00007f78a8f8eb69
RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007f78a9011df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000040015 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f78a91b5fa0 R15: 00007ffe71c509d8
 </TASK>

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/01 15:32 linux-6.6.y 3a8ababb8b6a 40127d41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/08/01 15:30 linux-6.6.y 3a8ababb8b6a 40127d41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/08/01 15:29 linux-6.6.y 3a8ababb8b6a 40127d41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/28 17:13 linux-6.6.y dbcb8d8e4163 6654ea9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/28 17:12 linux-6.6.y dbcb8d8e4163 6654ea9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/25 05:30 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/25 05:14 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/25 05:13 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/25 01:56 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/25 01:55 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/15 13:22 linux-6.6.y 9247f4e6573a 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in input_event
2025/07/15 13:22 linux-6.6.y 9247f4e6573a 03fcfc4b .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
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.