syzbot


possible deadlock in evdev_pass_values (2)

Status: upstream: reported on 2026/03/12 13:02
Reported-by: syzbot+952c5c5b06a51177537b@syzkaller.appspotmail.com
First crash: 23h43m, last: 23h43m
Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in evdev_pass_values fuse kernfs 4 351 1066d 1889d 0/29 closed as dup on 2021/07/02 09:55
linux-5.15 possible deadlock in evdev_pass_values (3) 4 11 562d 596d 0/3 auto-obsoleted due to no activity on 2024/11/05 23:17
linux-6.1 possible deadlock in evdev_pass_values (3) 4 17 647d 714d 0/3 auto-obsoleted due to no activity on 2024/08/12 15:10
linux-5.15 possible deadlock in evdev_pass_values (4) 4 2 402d 413d 0/3 auto-obsoleted due to no activity on 2025/05/14 14:17
linux-6.1 possible deadlock in evdev_pass_values 4 1 985d 985d 0/3 auto-obsoleted due to no activity on 2023/10/09 19:52
linux-6.6 possible deadlock in evdev_pass_values 4 2 217d 226d 0/2 auto-obsoleted due to no activity on 2025/11/15 13:39
linux-5.15 possible deadlock in evdev_pass_values 4 6 863d 966d 0/3 auto-obsoleted due to no activity on 2024/02/09 07:09
upstream possible deadlock in evdev_pass_values (2) input 4 1706 11d 1057d 0/29 upstream: reported on 2023/04/21 09:42
linux-6.1 possible deadlock in evdev_pass_values (4) 4 12 148d 344d 0/3 auto-obsoleted due to no activity on 2026/01/23 14:28
linux-5.15 possible deadlock in evdev_pass_values (2) 4 22 681d 758d 0/3 auto-obsoleted due to no activity on 2024/07/10 03:27
linux-6.1 possible deadlock in evdev_pass_values (2) 4 1 846d 846d 0/3 auto-obsoleted due to no activity on 2024/02/25 22:49
linux-5.15 possible deadlock in evdev_pass_values (5) 4 8 8d11h 199d 0/3 upstream: reported on 2025/08/26 05:46

Sample crash report:
=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Not tainted
-----------------------------------------------------
syz.0.6650/24772 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffffffff8ce0a058 (tasklist_lock){.+.+}-{2:2}, at: send_sigurg+0xf0/0x3c0 fs/fcntl.c:827

and this task is already holding:
ffff88805a206b18 (&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 SOFTIRQ-irq-safe lock:
 (&client->buffer_lock){..-.}-{2:2}

... which became SOFTIRQ-irq-safe at:
  lock_acquire+0x19e/0x420 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+0x905/0x12f0 drivers/input/input.c:161
  input_event_dispose+0x346/0x6c0 drivers/input/input.c:378
  input_event+0x8c/0xc0 drivers/input/input.c:435
  input_sync include/linux/input.h:450 [inline]
  hidinput_report_event+0xa1/0xf0 drivers/hid/hid-input.c:1750
  hid_report_raw_event+0x151d/0x1750 drivers/hid/hid-core.c:2038
  hid_input_report+0x434/0x510 drivers/hid/hid-core.c:2105
  hid_irq_in+0x479/0x6d0 drivers/hid/usbhid/hid-core.c:284
  __usb_hcd_giveback_urb+0x35f/0x520 drivers/usb/core/hcd.c:1650
  dummy_timer+0xc04/0x3080 drivers/usb/gadget/udc/dummy_hcd.c:1993
  __run_hrtimer kernel/time/hrtimer.c:1750 [inline]
  __hrtimer_run_queues+0x520/0xc40 kernel/time/hrtimer.c:1814
  hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1831
  handle_softirqs+0x280/0x820 kernel/softirq.c:578
  __do_softirq kernel/softirq.c:612 [inline]
  invoke_softirq kernel/softirq.c:452 [inline]
  __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
  irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
  sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
  lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758
  fs_reclaim_acquire+0x98/0x100 mm/page_alloc.c:3616
  might_alloc include/linux/sched/mm.h:303 [inline]
  slab_pre_alloc_hook+0x2a/0x310 mm/slab.h:714
  slab_alloc_node mm/slub.c:3477 [inline]
  __kmem_cache_alloc_node+0x53/0x250 mm/slub.c:3534
  __do_kmalloc_node mm/slab_common.c:1006 [inline]
  __kmalloc+0xa4/0x230 mm/slab_common.c:1020
  kmalloc include/linux/slab.h:604 [inline]
  kzalloc include/linux/slab.h:721 [inline]
  kobject_get_path+0xc3/0x2c0 lib/kobject.c:161
  kobject_uevent_env+0x28a/0x8b0 lib/kobject_uevent.c:544
  really_probe+0x715/0xb20 drivers/base/dd.c:708
  __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
  driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
  __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
  bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
  __device_attach+0x2c2/0x420 drivers/base/dd.c:1030
  bus_probe_device+0x180/0x260 drivers/base/bus.c:534
  device_add+0x85b/0xc20 drivers/base/core.c:3683
  hid_add_device+0x38d/0x530 drivers/hid/hid-core.c:2832
  usbhid_probe+0xe02/0x1220 drivers/hid/usbhid/hid-core.c:1447
  usb_probe_interface+0x5c9/0xb20 drivers/usb/core/driver.c:396
  call_driver_probe drivers/base/dd.c:-1 [inline]
  really_probe+0x25b/0xb20 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
  __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
  bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
  __device_attach+0x2c2/0x420 drivers/base/dd.c:1030
  bus_probe_device+0x180/0x260 drivers/base/bus.c:534
  device_add+0x85b/0xc20 drivers/base/core.c:3683
  usb_set_configuration+0x1a79/0x20c0 drivers/usb/core/message.c:2207
  usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:238
  usb_probe_device+0x13d/0x270 drivers/usb/core/driver.c:293
  call_driver_probe drivers/base/dd.c:-1 [inline]
  really_probe+0x25b/0xb20 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
  __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
  bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
  __device_attach+0x2c2/0x420 drivers/base/dd.c:1030
  bus_probe_device+0x180/0x260 drivers/base/bus.c:534
  device_add+0x85b/0xc20 drivers/base/core.c:3683
  usb_new_device+0xa3c/0x1660 drivers/usb/core/hub.c:2660
  hub_port_connect drivers/usb/core/hub.c:5529 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
  port_event drivers/usb/core/hub.c:5833 [inline]
  hub_event+0x29bf/0x49f0 drivers/usb/core/hub.c:5915
  process_one_work kernel/workqueue.c:2653 [inline]
  process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
  worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
  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 SOFTIRQ-irq-unsafe lock:
 (tasklist_lock){.+.+}-{2:2}

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x19e/0x420 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+0x294/0xae0 kernel/exit.c:1607
  kernel_wait+0xd7/0x1c0 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:2653 [inline]
  process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
  worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
  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:
  &client->buffer_lock --> &f->f_owner.lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(&client->buffer_lock);
                               lock(&f->f_owner.lock);
  <Interrupt>
    lock(&client->buffer_lock);

 *** DEADLOCK ***

2 locks held by syz.0.6650/24772:
 #0: ffff88807bbe7e80 (&u->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #0: ffff88807bbe7e80 (&u->lock){+.+.}-{2:2}, at: queue_oob+0x1e2/0x4f0 net/unix/af_unix.c:2190
 #1: ffff88805a206b18 (&f->f_owner.lock){....}-{2:2}, at: send_sigurg+0x29/0x3c0 fs/fcntl.c:811

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
  -> (&client->buffer_lock){..-.}-{2:2} {
     IN-SOFTIRQ-W at:
                        lock_acquire+0x19e/0x420 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+0x905/0x12f0 drivers/input/input.c:161
                        input_event_dispose+0x346/0x6c0 drivers/input/input.c:378
                        input_event+0x8c/0xc0 drivers/input/input.c:435
                        input_sync include/linux/input.h:450 [inline]
                        hidinput_report_event+0xa1/0xf0 drivers/hid/hid-input.c:1750
                        hid_report_raw_event+0x151d/0x1750 drivers/hid/hid-core.c:2038
                        hid_input_report+0x434/0x510 drivers/hid/hid-core.c:2105
                        hid_irq_in+0x479/0x6d0 drivers/hid/usbhid/hid-core.c:284
                        __usb_hcd_giveback_urb+0x35f/0x520 drivers/usb/core/hcd.c:1650
                        dummy_timer+0xc04/0x3080 drivers/usb/gadget/udc/dummy_hcd.c:1993
                        __run_hrtimer kernel/time/hrtimer.c:1750 [inline]
                        __hrtimer_run_queues+0x520/0xc40 kernel/time/hrtimer.c:1814
                        hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1831
                        handle_softirqs+0x280/0x820 kernel/softirq.c:578
                        __do_softirq kernel/softirq.c:612 [inline]
                        invoke_softirq kernel/softirq.c:452 [inline]
                        __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
                        irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
                        instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
                        sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
                        asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
                        lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758
                        fs_reclaim_acquire+0x98/0x100 mm/page_alloc.c:3616
                        might_alloc include/linux/sched/mm.h:303 [inline]
                        slab_pre_alloc_hook+0x2a/0x310 mm/slab.h:714
                        slab_alloc_node mm/slub.c:3477 [inline]
                        __kmem_cache_alloc_node+0x53/0x250 mm/slub.c:3534
                        __do_kmalloc_node mm/slab_common.c:1006 [inline]
                        __kmalloc+0xa4/0x230 mm/slab_common.c:1020
                        kmalloc include/linux/slab.h:604 [inline]
                        kzalloc include/linux/slab.h:721 [inline]
                        kobject_get_path+0xc3/0x2c0 lib/kobject.c:161
                        kobject_uevent_env+0x28a/0x8b0 lib/kobject_uevent.c:544
                        really_probe+0x715/0xb20 drivers/base/dd.c:708
                        __driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
                        driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
                        __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
                        bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
                        __device_attach+0x2c2/0x420 drivers/base/dd.c:1030
                        bus_probe_device+0x180/0x260 drivers/base/bus.c:534
                        device_add+0x85b/0xc20 drivers/base/core.c:3683
                        hid_add_device+0x38d/0x530 drivers/hid/hid-core.c:2832
                        usbhid_probe+0xe02/0x1220 drivers/hid/usbhid/hid-core.c:1447
                        usb_probe_interface+0x5c9/0xb20 drivers/usb/core/driver.c:396
                        call_driver_probe drivers/base/dd.c:-1 [inline]
                        really_probe+0x25b/0xb20 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
                        __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
                        bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
                        __device_attach+0x2c2/0x420 drivers/base/dd.c:1030
                        bus_probe_device+0x180/0x260 drivers/base/bus.c:534
                        device_add+0x85b/0xc20 drivers/base/core.c:3683
                        usb_set_configuration+0x1a79/0x20c0 drivers/usb/core/message.c:2207
                        usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:238
                        usb_probe_device+0x13d/0x270 drivers/usb/core/driver.c:293
                        call_driver_probe drivers/base/dd.c:-1 [inline]
                        really_probe+0x25b/0xb20 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
                        __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:958
                        bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
                        __device_attach+0x2c2/0x420 drivers/base/dd.c:1030
                        bus_probe_device+0x180/0x260 drivers/base/bus.c:534
                        device_add+0x85b/0xc20 drivers/base/core.c:3683
                        usb_new_device+0xa3c/0x1660 drivers/usb/core/hub.c:2660
                        hub_port_connect drivers/usb/core/hub.c:5529 [inline]
                        hub_port_connect_change drivers/usb/core/hub.c:5669 [inline]
                        port_event drivers/usb/core/hub.c:5833 [inline]
                        hub_event+0x29bf/0x49f0 drivers/usb/core/hub.c:5915
                        process_one_work kernel/workqueue.c:2653 [inline]
                        process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
                        worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
                        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+0x19e/0x420 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+0x905/0x12f0 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+0x35f/0x490 drivers/input/evdev.c:530
                       vfs_write+0x296/0x990 fs/read_write.c:582
                       ksys_write+0x150/0x260 fs/read_write.c:637
                       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
                       do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
                       entry_SYSCALL_64_after_hwframe+0x68/0xd2
   }
   ... key      at: [<ffffffff9762cd20>] evdev_open.__key.28+0x0/0x20
 -> (&new->fa_lock){....}-{2:2} {
    INITIAL USE at:
                     lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                     _raw_write_lock_irq+0xaf/0xf0 kernel/locking/spinlock.c:326
                     fasync_remove_entry+0xf4/0x1c0 fs/fcntl.c:867
                     sock_fasync+0x88/0xf0 net/socket.c:1445
                     __fput+0x7f3/0x970 fs/file_table.c:381
                     task_work_run+0x1d4/0x260 kernel/task_work.c:245
                     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+0xee/0x180 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+0x61/0xa0 arch/x86/entry/common.c:82
                     entry_SYSCALL_64_after_hwframe+0x68/0xd2
    INITIAL READ USE at:
                          lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
                          __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
                          _raw_read_lock_irqsave+0xbc/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+0x17f/0x280 include/net/sock.h:2615
                          mptcp_destroy_common+0x113/0x4c0 net/mptcp/protocol.c:3488
                          mptcp_disconnect+0x204/0x520 net/mptcp/protocol.c:3297
                          inet_shutdown+0x1be/0x370 net/ipv4/af_inet.c:934
                          __sys_shutdown_sock net/socket.c:2435 [inline]
                          __sys_shutdown net/socket.c:2447 [inline]
                          __do_sys_shutdown net/socket.c:2455 [inline]
                          __se_sys_shutdown net/socket.c:2453 [inline]
                          __x64_sys_shutdown+0x174/0x1d0 net/socket.c:2453
                          do_syscall_x64 arch/x86/entry/common.c:46 [inline]
                          do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
                          entry_SYSCALL_64_after_hwframe+0x68/0xd2
  }
  ... key      at: [<ffffffff97333b20>] fasync_insert_entry.__key+0x0/0x20
  ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
   _raw_read_lock_irqsave+0xbc/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+0x905/0x12f0 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+0x35f/0x490 drivers/input/evdev.c:530
   vfs_write+0x296/0x990 fs/read_write.c:582
   ksys_write+0x150/0x260 fs/read_write.c:637
   do_syscall_x64 arch/x86/entry/common.c:46 [inline]
   do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
   entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> (&f->f_owner.lock){....}-{2:2} {
   INITIAL USE at:
                   lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                   _raw_write_lock_irq+0xaf/0xf0 kernel/locking/spinlock.c:326
                   __f_setown+0x3b/0x330 fs/fcntl.c:92
                   fcntl_dirnotify+0x6e2/0x8d0 fs/notify/dnotify/dnotify.c:369
                   do_fcntl+0x390/0x1490 fs/fcntl.c:400
                   __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:46 [inline]
                   do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
                   entry_SYSCALL_64_after_hwframe+0x68/0xd2
   INITIAL READ USE at:
                        lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
                        __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
                        _raw_read_lock_irqsave+0xbc/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+0x17f/0x280 include/net/sock.h:2615
                        mptcp_destroy_common+0x113/0x4c0 net/mptcp/protocol.c:3488
                        mptcp_disconnect+0x204/0x520 net/mptcp/protocol.c:3297
                        inet_shutdown+0x1be/0x370 net/ipv4/af_inet.c:934
                        __sys_shutdown_sock net/socket.c:2435 [inline]
                        __sys_shutdown net/socket.c:2447 [inline]
                        __do_sys_shutdown net/socket.c:2455 [inline]
                        __se_sys_shutdown net/socket.c:2453 [inline]
                        __x64_sys_shutdown+0x174/0x1d0 net/socket.c:2453
                        do_syscall_x64 arch/x86/entry/common.c:46 [inline]
                        do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
                        entry_SYSCALL_64_after_hwframe+0x68/0xd2
 }
 ... key      at: [<ffffffff97332ea0>] init_file.__key+0x0/0x20
 ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
   _raw_read_lock_irqsave+0xbc/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+0x17f/0x280 include/net/sock.h:2615
   mptcp_destroy_common+0x113/0x4c0 net/mptcp/protocol.c:3488
   mptcp_disconnect+0x204/0x520 net/mptcp/protocol.c:3297
   inet_shutdown+0x1be/0x370 net/ipv4/af_inet.c:934
   __sys_shutdown_sock net/socket.c:2435 [inline]
   __sys_shutdown net/socket.c:2447 [inline]
   __do_sys_shutdown net/socket.c:2455 [inline]
   __se_sys_shutdown net/socket.c:2453 [inline]
   __x64_sys_shutdown+0x174/0x1d0 net/socket.c:2453
   do_syscall_x64 arch/x86/entry/common.c:46 [inline]
   do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
   entry_SYSCALL_64_after_hwframe+0x68/0xd2


the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
-> (tasklist_lock){.+.+}-{2:2} {
   HARDIRQ-ON-R at:
                    lock_acquire+0x19e/0x420 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+0x294/0xae0 kernel/exit.c:1607
                    kernel_wait+0xd7/0x1c0 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:2653 [inline]
                    process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
                    worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
                    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+0x19e/0x420 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+0x294/0xae0 kernel/exit.c:1607
                    kernel_wait+0xd7/0x1c0 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:2653 [inline]
                    process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
                    worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
                    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+0x19e/0x420 kernel/locking/lockdep.c:5754
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                   _raw_write_lock_irq+0xaf/0xf0 kernel/locking/spinlock.c:326
                   copy_process+0x2275/0x3d80 kernel/fork.c:2631
                   kernel_clone+0x24b/0x8a0 kernel/fork.c:2914
                   user_mode_thread+0x111/0x180 kernel/fork.c:2992
                   rest_init+0x27/0x300 init/main.c:709
                   arch_call_rest_init+0xe/0x10 init/main.c:841
                   start_kernel+0x459/0x4e0 init/main.c:1086
                   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+0x19e/0x420 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+0x294/0xae0 kernel/exit.c:1607
                        kernel_wait+0xd7/0x1c0 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:2653 [inline]
                        process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
                        worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
                        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: [<ffffffff8ce0a058>] 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:3412
   queue_oob+0x3f1/0x4f0 net/unix/af_unix.c:2207
   unix_stream_sendmsg+0xaf0/0xbf0 net/unix/af_unix.c:2326
   sock_sendmsg_nosec net/socket.c:730 [inline]
   __sock_sendmsg net/socket.c:745 [inline]
   ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
   ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
   __sys_sendmmsg+0x2ca/0x510 net/socket.c:2734
   __do_sys_sendmmsg net/socket.c:2763 [inline]
   __se_sys_sendmmsg net/socket.c:2760 [inline]
   __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2760
   do_syscall_x64 arch/x86/entry/common.c:46 [inline]
   do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
   entry_SYSCALL_64_after_hwframe+0x68/0xd2


stack backtrace:
CPU: 0 PID: 24772 Comm: syz.0.6650 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 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+0x6851/0x7d40 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 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:3412
 queue_oob+0x3f1/0x4f0 net/unix/af_unix.c:2207
 unix_stream_sendmsg+0xaf0/0xbf0 net/unix/af_unix.c:2326
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmmsg+0x2ca/0x510 net/socket.c:2734
 __do_sys_sendmmsg net/socket.c:2763 [inline]
 __se_sys_sendmmsg net/socket.c:2760 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2760
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0c21d9c799
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:00007f0c22ccf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f0c22015fa0 RCX: 00007f0c21d9c799
RDX: 0000000000000001 RSI: 0000200000011500 RDI: 0000000000000003
RBP: 00007f0c21e32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000040015 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c22016038 R14: 00007f0c22015fa0 R15: 00007ffcff77a058
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/12 13:01 linux-6.6.y 4fc00fe35d46 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in evdev_pass_values
* Struck through repros no longer work on HEAD.