netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. ======================================================== WARNING: possible irq lock inversion dependency detected 6.18.0-next-20251210 #1 Tainted: G W -------------------------------------------------------- syz-executor.4/13626 just changed the state of lock: ffff88800a14f230 (&dev->event_lock){..-.}-{3:3}, at: input_inject_event+0x9f/0x3b0 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 --> &client->buffer_lock --> tasklist_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(&dev->event_lock); lock(&client->buffer_lock); lock(&dev->event_lock); *** DEADLOCK *** 2 locks held by syz-executor.4/13626: #0: ffff88801b8f00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 #1: ffffffff85e21ae0 (rcu_read_lock){....}-{1:3}, at: led_trigger_event+0x61/0x270 the shortest dependencies between 2nd lock and 1st lock: -> (tasklist_lock){.+.+}-{3:3} { HARDIRQ-ON-R at: lock_acquire+0x15e/0x2d0 _raw_read_lock+0x5c/0x70 __do_wait+0x13e/0x8f0 do_wait+0x19f/0x530 kernel_wait+0x9f/0x160 call_usermodehelper_exec_work+0xf9/0x180 process_one_work+0x8e1/0x1960 worker_thread+0x67e/0xe90 kthread+0x3c8/0x740 ret_from_fork+0x67a/0x7a0 ret_from_fork_asm+0x1a/0x30 SOFTIRQ-ON-R at: lock_acquire+0x15e/0x2d0 _raw_read_lock+0x5c/0x70 __do_wait+0x13e/0x8f0 do_wait+0x19f/0x530 kernel_wait+0x9f/0x160 call_usermodehelper_exec_work+0xf9/0x180 process_one_work+0x8e1/0x1960 worker_thread+0x67e/0xe90 kthread+0x3c8/0x740 ret_from_fork+0x67a/0x7a0 ret_from_fork_asm+0x1a/0x30 INITIAL USE at: lock_acquire+0x15e/0x2d0 _raw_write_lock_irq+0x33/0x50 copy_process+0x4e71/0x7230 kernel_clone+0xea/0x7c0 user_mode_thread+0xc8/0x110 rest_init+0x24/0x290 start_kernel+0x3fa/0x510 x86_64_start_reservations+0x18/0x30 x86_64_start_kernel+0x109/0x120 common_startup_64+0x13e/0x148 INITIAL READ USE at: lock_acquire+0x15e/0x2d0 _raw_read_lock+0x5c/0x70 __do_wait+0x13e/0x8f0 do_wait+0x19f/0x530 kernel_wait+0x9f/0x160 call_usermodehelper_exec_work+0xf9/0x180 process_one_work+0x8e1/0x1960 worker_thread+0x67e/0xe90 kthread+0x3c8/0x740 ret_from_fork+0x67a/0x7a0 ret_from_fork_asm+0x1a/0x30 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: _raw_read_lock+0x5c/0x70 send_sigio+0xbb/0x370 kill_fasync+0x218/0x520 lease_break_callback+0x23/0x30 __break_lease+0x6c4/0x1760 vfs_truncate+0x30d/0x480 do_sys_truncate.part.0+0xfa/0x140 __x64_sys_truncate+0x6d/0xa0 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&f_owner->lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x15e/0x2d0 _raw_write_lock_irq+0x33/0x50 __f_setown+0x60/0x3c0 fcntl_dirnotify+0x623/0xb60 do_fcntl+0x230/0x1500 __x64_sys_fcntl+0x155/0x1f0 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x15e/0x2d0 _raw_read_lock_irqsave+0x75/0x90 send_sigio+0x31/0x370 kill_fasync+0x218/0x520 lease_break_callback+0x23/0x30 __break_lease+0x6c4/0x1760 vfs_truncate+0x30d/0x480 do_sys_truncate.part.0+0xfa/0x140 __x64_sys_truncate+0x6d/0xa0 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] __key.1+0x0/0x40 ... acquired at: _raw_read_lock_irqsave+0x75/0x90 send_sigio+0x31/0x370 kill_fasync+0x218/0x520 lease_break_callback+0x23/0x30 __break_lease+0x6c4/0x1760 vfs_truncate+0x30d/0x480 do_sys_truncate.part.0+0xfa/0x140 __x64_sys_truncate+0x6d/0xa0 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&new->fa_lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x15e/0x2d0 _raw_write_lock_irq+0x33/0x50 fasync_remove_entry+0xb2/0x1e0 fasync_helper+0xa6/0xc0 __fput+0x94b/0xb50 fput_close_sync+0x10f/0x230 __x64_sys_close+0x8f/0x120 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x15e/0x2d0 _raw_read_lock_irqsave+0x75/0x90 kill_fasync+0x137/0x520 evdev_pass_values.part.0+0x665/0x940 evdev_events+0x3b5/0x430 input_pass_values+0x708/0x860 input_handle_event+0xdcf/0x13d0 input_inject_event+0x1e5/0x3b0 evdev_write+0x2e1/0x420 vfs_write+0x2b7/0x1150 ksys_write+0x1ef/0x240 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] __key.0+0x0/0x40 ... acquired at: _raw_read_lock_irqsave+0x75/0x90 kill_fasync+0x137/0x520 evdev_pass_values.part.0+0x665/0x940 evdev_events+0x3b5/0x430 input_pass_values+0x708/0x860 input_handle_event+0xdcf/0x13d0 input_inject_event+0x1e5/0x3b0 evdev_write+0x2e1/0x420 vfs_write+0x2b7/0x1150 ksys_write+0x1ef/0x240 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&client->buffer_lock){....}-{3:3} { INITIAL USE at: lock_acquire+0x15e/0x2d0 _raw_spin_lock+0x2b/0x40 evdev_pass_values.part.0+0xf6/0x940 evdev_events+0x3b5/0x430 input_pass_values+0x708/0x860 input_handle_event+0xdcf/0x13d0 input_inject_event+0x1e5/0x3b0 evdev_write+0x2e1/0x420 vfs_write+0x2b7/0x1150 ksys_write+0x1ef/0x240 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] __key.93+0x0/0x40 ... acquired at: _raw_spin_lock+0x2b/0x40 evdev_pass_values.part.0+0xf6/0x940 evdev_events+0x3b5/0x430 input_pass_values+0x708/0x860 input_handle_event+0xdcf/0x13d0 input_inject_event+0x1e5/0x3b0 evdev_write+0x2e1/0x420 vfs_write+0x2b7/0x1150 ksys_write+0x1ef/0x240 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&dev->event_lock){..-.}-{3:3} { IN-SOFTIRQ-W at: lock_acquire+0x15e/0x2d0 _raw_spin_lock_irqsave+0x3a/0x60 input_inject_event+0x9f/0x3b0 led_set_brightness+0x215/0x290 led_trigger_event+0xda/0x270 kbd_bh+0x23a/0x310 tasklet_action_common+0x270/0x730 handle_softirqs+0x1b1/0x7d0 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_apic_timer_interrupt+0x70/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 _raw_spin_unlock_irq+0x2b/0x40 n_tty_ioctl_helper+0x114/0x2d0 n_tty_ioctl+0x4f/0x390 tty_ioctl+0x828/0x17f0 __x64_sys_ioctl+0x18f/0x210 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL USE at: lock_acquire+0x15e/0x2d0 _raw_spin_lock_irqsave+0x3a/0x60 input_inject_event+0x9f/0x3b0 led_set_brightness+0x215/0x290 kbd_led_trigger_activate+0xcd/0x110 led_trigger_set+0x4cc/0xaa0 led_trigger_set_default+0x1e7/0x2e0 led_classdev_register_ext+0x615/0x950 input_leds_connect+0x49b/0x870 input_attach_handler+0x17a/0x260 input_register_device+0x9ff/0x1050 atkbd_connect+0x5e6/0xa10 serio_driver_probe+0x84/0xe0 really_probe+0x240/0x820 __driver_probe_device+0x2c4/0x380 driver_probe_device+0x4e/0x2a0 __driver_attach+0x1b0/0x590 bus_for_each_dev+0x12b/0x1c0 serio_handle_event+0x23b/0xaa0 process_one_work+0x8e1/0x1960 worker_thread+0x67e/0xe90 kthread+0x3c8/0x740 ret_from_fork+0x67a/0x7a0 ret_from_fork_asm+0x1a/0x30 } ... key at: [] __key.4+0x0/0x40 ... acquired at: __lock_acquire+0x975/0x2250 lock_acquire+0x15e/0x2d0 _raw_spin_lock_irqsave+0x3a/0x60 input_inject_event+0x9f/0x3b0 led_set_brightness+0x215/0x290 led_trigger_event+0xda/0x270 kbd_bh+0x23a/0x310 tasklet_action_common+0x270/0x730 handle_softirqs+0x1b1/0x7d0 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_apic_timer_interrupt+0x70/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 _raw_spin_unlock_irq+0x2b/0x40 n_tty_ioctl_helper+0x114/0x2d0 n_tty_ioctl+0x4f/0x390 tty_ioctl+0x828/0x17f0 __x64_sys_ioctl+0x18f/0x210 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f stack backtrace: CPU: 1 UID: 0 PID: 13626 Comm: syz-executor.4 Tainted: G W 6.18.0-next-20251210 #1 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xca/0x120 print_irq_inversion_bug.part.0+0x20a/0x260 mark_lock+0x850/0xf70 __lock_acquire+0x975/0x2250 lock_acquire+0x15e/0x2d0 _raw_spin_lock_irqsave+0x3a/0x60 input_inject_event+0x9f/0x3b0 led_set_brightness+0x215/0x290 led_trigger_event+0xda/0x270 kbd_bh+0x23a/0x310 tasklet_action_common+0x270/0x730 handle_softirqs+0x1b1/0x7d0 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_apic_timer_interrupt+0x70/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:_raw_spin_unlock_irq+0x2b/0x40 Code: 0f 1e fa 55 48 8b 74 24 08 48 89 fd 48 83 c7 18 e8 2a 59 84 fc 48 89 ef e8 c2 a8 84 fc e8 6d c6 af fc fb 65 ff 0d c5 d8 dd 02 <74> 06 5d e9 8d 27 00 00 0f 1f 44 00 00 5d e9 82 27 00 00 66 90 90 RSP: 0018:ffff88805555fcc0 EFLAGS: 00000246 RAX: 00000000000001a7 RBX: ffffffff828e0c30 RCX: 0000000000000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84ce6763 RBP: ffff88801b8f0450 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff86664757 R11: ffff88806cf37758 R12: 0000000000000000 R13: ffff88801b8f0000 R14: 0000000000000000 R15: ffffffffffffffea n_tty_ioctl_helper+0x114/0x2d0 n_tty_ioctl+0x4f/0x390 tty_ioctl+0x828/0x17f0 __x64_sys_ioctl+0x18f/0x210 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9e5195bb19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9e4eed1188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9e51a6ef60 RCX: 00007f9e5195bb19 RDX: 0000000000000000 RSI: 000000000000540a RDI: 0000000000000003 RBP: 00007f9e519b5f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc7ab3596f R14: 00007f9e4eed1300 R15: 0000000000022000 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. ---------------- Code disassembly (best guess): 0: 0f 1e fa nop %edx 3: 55 push %rbp 4: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 9: 48 89 fd mov %rdi,%rbp c: 48 83 c7 18 add $0x18,%rdi 10: e8 2a 59 84 fc callq 0xfc84593f 15: 48 89 ef mov %rbp,%rdi 18: e8 c2 a8 84 fc callq 0xfc84a8df 1d: e8 6d c6 af fc callq 0xfcafc68f 22: fb sti 23: 65 ff 0d c5 d8 dd 02 decl %gs:0x2ddd8c5(%rip) # 0x2ddd8ef * 2a: 74 06 je 0x32 <-- trapping instruction 2c: 5d pop %rbp 2d: e9 8d 27 00 00 jmpq 0x27bf 32: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 37: 5d pop %rbp 38: e9 82 27 00 00 jmpq 0x27bf 3d: 66 90 xchg %ax,%ax 3f: 90 nop