======================================================== WARNING: possible irq lock inversion dependency detected 6.16.0-syzkaller #0 Not tainted -------------------------------------------------------- ksoftirqd/0/15 just changed the state of lock: ffff888029b77230 (&dev->event_lock#2){..-.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] ffff888029b77230 (&dev->event_lock#2){..-.}-{3:3}, at: input_inject_event+0xab/0x320 drivers/input/input.c:418 but this lock took another, SOFTIRQ-READ-unsafe lock in the past: (tasklist_lock){.+.+}-{3:3} and interrupts could create inverse lock ordering between them. 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); lock(&dev->event_lock#2); *** DEADLOCK *** 1 lock held by ksoftirqd/0/15: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: led_trigger_event+0x4b/0x210 drivers/leds/led-triggers.c:418 the shortest dependencies between 2nd lock and 1st lock: -> (tasklist_lock){.+.+}-{3:3} { HARDIRQ-ON-R at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 __do_wait+0xde/0x740 kernel/exit.c:1665 do_wait+0x1f8/0x520 kernel/exit.c:1709 kernel_wait+0xab/0x170 kernel/exit.c:1885 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 SOFTIRQ-ON-R at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 __do_wait+0xde/0x740 kernel/exit.c:1665 do_wait+0x1f8/0x520 kernel/exit.c:1709 kernel_wait+0xab/0x170 kernel/exit.c:1885 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INITIAL USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326 copy_process+0x21d5/0x3b80 kernel/fork.c:2315 kernel_clone+0x224/0x7f0 kernel/fork.c:2599 user_mode_thread+0xdd/0x140 kernel/fork.c:2677 rest_init+0x23/0x300 init/main.c:710 start_kernel+0x47d/0x500 init/main.c:1102 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 INITIAL READ USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 __do_wait+0xde/0x740 kernel/exit.c:1665 do_wait+0x1f8/0x520 kernel/exit.c:1709 kernel_wait+0xab/0x170 kernel/exit.c:1885 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 send_sigurg+0x12b/0x420 fs/fcntl.c:967 sk_send_sigurg+0x6c/0x2e0 net/core/sock.c:3641 queue_oob+0x490/0x5a0 net/unix/af_unix.c:2303 unix_stream_sendmsg+0xaf9/0xc90 net/unix/af_unix.c:2429 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:727 ____sys_sendmsg+0x52d/0x830 net/socket.c:2566 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 __sys_sendmmsg+0x227/0x430 net/socket.c:2709 __do_sys_sendmmsg net/socket.c:2736 [inline] __se_sys_sendmmsg net/socket.c:2733 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2733 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&f_owner->lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326 __f_setown+0x67/0x370 fs/fcntl.c:136 fcntl_dirnotify+0x3fa/0x6a0 fs/notify/dnotify/dnotify.c:369 do_fcntl+0x6d0/0x1910 fs/fcntl.c:539 __do_sys_fcntl fs/fcntl.c:591 [inline] __se_sys_fcntl+0xc8/0x150 fs/fcntl.c:576 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236 send_sigio+0x38/0x370 fs/fcntl.c:907 kill_fasync_rcu fs/fcntl.c:1133 [inline] kill_fasync+0x24d/0x4d0 fs/fcntl.c:1148 lease_break_callback+0x26/0x30 fs/locks.c:558 __break_lease+0x6a5/0x1620 fs/locks.c:1592 vfs_truncate+0x428/0x520 fs/open.c:112 do_sys_truncate+0xdb/0x190 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] file_f_owner_allocate.__key+0x0/0x20 ... acquired at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236 send_sigio+0x38/0x370 fs/fcntl.c:907 kill_fasync_rcu fs/fcntl.c:1133 [inline] kill_fasync+0x24d/0x4d0 fs/fcntl.c:1148 lease_break_callback+0x26/0x30 fs/locks.c:558 __break_lease+0x6a5/0x1620 fs/locks.c:1592 vfs_truncate+0x428/0x520 fs/open.c:112 do_sys_truncate+0xdb/0x190 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&new->fa_lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:326 fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:1001 sock_fasync+0x85/0xf0 net/socket.c:1416 __fput+0x8a2/0xa70 fs/file_table.c:462 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1124 [inline] kill_fasync+0x199/0x4d0 fs/fcntl.c:1148 lease_break_callback+0x26/0x30 fs/locks.c:558 __break_lease+0x6a5/0x1620 fs/locks.c:1592 vfs_truncate+0x428/0x520 fs/open.c:112 do_sys_truncate+0xdb/0x190 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] fasync_insert_entry.__key+0x0/0x20 ... acquired at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1124 [inline] kill_fasync+0x199/0x4d0 fs/fcntl.c:1148 __pass_event drivers/input/evdev.c:240 [inline] evdev_pass_values+0x627/0xbd0 drivers/input/evdev.c:278 evdev_events+0x1e6/0x340 drivers/input/evdev.c:306 input_pass_values+0x285/0x890 drivers/input/input.c:127 input_event_dispose+0x330/0x6b0 drivers/input/input.c:341 input_inject_event+0x1fe/0x320 drivers/input/input.c:423 evdev_write+0x2fc/0x480 drivers/input/evdev.c:528 vfs_write+0x27e/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&client->buffer_lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __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+0xb9/0xbd0 drivers/input/evdev.c:261 evdev_events+0x1e6/0x340 drivers/input/evdev.c:306 input_pass_values+0x285/0x890 drivers/input/input.c:127 input_event_dispose+0x330/0x6b0 drivers/input/input.c:341 input_inject_event+0x1fe/0x320 drivers/input/input.c:423 evdev_write+0x2fc/0x480 drivers/input/evdev.c:528 vfs_write+0x27e/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] evdev_open.__key.25+0x0/0x20 ... acquired at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __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+0xb9/0xbd0 drivers/input/evdev.c:261 evdev_events+0x1e6/0x340 drivers/input/evdev.c:306 input_pass_values+0x285/0x890 drivers/input/input.c:127 input_event_dispose+0x330/0x6b0 drivers/input/input.c:341 input_inject_event+0x1fe/0x320 drivers/input/input.c:423 evdev_write+0x2fc/0x480 drivers/input/evdev.c:528 vfs_write+0x27e/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&dev->event_lock#2){..-.}-{3:3} { IN-SOFTIRQ-W at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] input_inject_event+0xab/0x320 drivers/input/input.c:418 led_trigger_event+0x138/0x210 drivers/leds/led-triggers.c:420 kbd_propagate_led_state drivers/tty/vt/keyboard.c:1073 [inline] kbd_bh+0x1c6/0x2e0 drivers/tty/vt/keyboard.c:1262 tasklet_action_common+0x369/0x580 kernel/softirq.c:829 handle_softirqs+0x283/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INITIAL USE at: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] input_inject_event+0xab/0x320 drivers/input/input.c:418 kbd_led_trigger_activate+0xbc/0x100 drivers/tty/vt/keyboard.c:1029 led_trigger_set+0x52d/0x950 drivers/leds/led-triggers.c:220 led_match_default_trigger drivers/leds/led-triggers.c:277 [inline] led_trigger_set_default+0x260/0x2a0 drivers/leds/led-triggers.c:300 led_classdev_register_ext+0x73d/0x930 drivers/leds/led-class.c:566 led_classdev_register include/linux/leds.h:274 [inline] input_leds_connect+0x517/0x790 drivers/input/input-leds.c:145 input_attach_handler drivers/input/input.c:993 [inline] input_register_device+0xceb/0x10b0 drivers/input/input.c:2412 atkbd_connect+0x70e/0x9c0 drivers/input/keyboard/atkbd.c:1340 serio_connect_driver drivers/input/serio/serio.c:43 [inline] serio_driver_probe+0x82/0xa0 drivers/input/serio/serio.c:747 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26a/0x9a0 drivers/base/dd.c:657 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799 driver_probe_device+0x4f/0x430 drivers/base/dd.c:829 __driver_attach+0x452/0x700 drivers/base/dd.c:1215 bus_for_each_dev+0x230/0x2b0 drivers/base/bus.c:370 serio_attach_driver drivers/input/serio/serio.c:776 [inline] serio_handle_event+0x1a2/0x860 drivers/input/serio/serio.c:213 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] input_allocate_device.__key.5+0x0/0x20 ... acquired at: mark_lock+0x11b/0x190 kernel/locking/lockdep.c:4756 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0x680/0xd20 kernel/locking/lockdep.c:5194 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] input_inject_event+0xab/0x320 drivers/input/input.c:418 led_trigger_event+0x138/0x210 drivers/leds/led-triggers.c:420 kbd_propagate_led_state drivers/tty/vt/keyboard.c:1073 [inline] kbd_bh+0x1c6/0x2e0 drivers/tty/vt/keyboard.c:1262 tasklet_action_common+0x369/0x580 kernel/softirq.c:829 handle_softirqs+0x283/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 stack backtrace: CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_irq_inversion_bug+0x1d2/0x1e0 kernel/locking/lockdep.c:4128 mark_lock_irq+0x35f/0x390 kernel/locking/lockdep.c:-1 mark_lock+0x11b/0x190 kernel/locking/lockdep.c:4756 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0x680/0xd20 kernel/locking/lockdep.c:5194 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] input_inject_event+0xab/0x320 drivers/input/input.c:418 led_trigger_event+0x138/0x210 drivers/leds/led-triggers.c:420 kbd_propagate_led_state drivers/tty/vt/keyboard.c:1073 [inline] kbd_bh+0x1c6/0x2e0 drivers/tty/vt/keyboard.c:1262 tasklet_action_common+0x369/0x580 kernel/softirq.c:829 handle_softirqs+0x283/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245