===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected syzkaller #0 Tainted: G L ----------------------------------------------------- syz.9.2778/14396 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff8e00c098 (tasklist_lock){.+.+}-{3:3}, at: send_sigurg+0xed/0xc80 fs/fcntl.c:978 and this task is already holding: ffff88814d814220 (&f_owner->lock){....}-{3:3}, at: send_sigurg+0x5f/0xc80 fs/fcntl.c:962 which would create a new lock dependency: (&f_owner->lock){....}-{3:3} -> (tasklist_lock){.+.+}-{3:3} but this new dependency connects a SOFTIRQ-irq-safe lock: (&dev->event_lock#2){..-.}-{3:3} ... which became SOFTIRQ-irq-safe at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] input_event drivers/input/input.c:395 [inline] input_event+0x74/0xd0 drivers/input/input.c:391 input_report_key include/linux/input.h:439 [inline] atp_complete_geyser_3_4+0xca9/0x16f0 drivers/input/mouse/appletouch.c:750 __usb_hcd_giveback_urb+0x38b/0x610 drivers/usb/core/hcd.c:1661 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745 dummy_timer+0x1809/0x3ad0 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:751 rcu_read_lock include/linux/rcupdate.h:868 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xa86/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6876 tomoyo_path_number_perm+0x470/0x580 security/tomoyo/file.c:736 security_file_ioctl+0x9b/0x240 security/security.c:2435 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0xb7/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f to a SOFTIRQ-irq-unsafe lock: (tasklist_lock){.+.+}-{3:3} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 __do_wait+0x105/0x890 kernel/exit.c:1672 do_wait+0x21d/0x570 kernel/exit.c:1716 kernel_wait+0x9f/0x160 kernel/exit.c:1892 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 other info that might help us debug this: Chain exists of: &dev->event_lock#2 --> &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_owner->lock); lock(&dev->event_lock#2); *** DEADLOCK *** 2 locks held by syz.9.2778/14396: #0: ffff88803143cce0 (&u->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #0: ffff88803143cce0 (&u->lock){+.+.}-{3:3}, at: queue_oob net/unix/af_unix.c:2336 [inline] #0: ffff88803143cce0 (&u->lock){+.+.}-{3:3}, at: unix_stream_sendmsg+0xd33/0x1320 net/unix/af_unix.c:2491 #1: ffff88814d814220 (&f_owner->lock){....}-{3:3}, at: send_sigurg+0x5f/0xc80 fs/fcntl.c:962 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&dev->event_lock#2){..-.}-{3:3} { IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] input_event drivers/input/input.c:395 [inline] input_event+0x74/0xd0 drivers/input/input.c:391 input_report_key include/linux/input.h:439 [inline] atp_complete_geyser_3_4+0xca9/0x16f0 drivers/input/mouse/appletouch.c:750 __usb_hcd_giveback_urb+0x38b/0x610 drivers/usb/core/hcd.c:1661 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745 dummy_timer+0x1809/0x3ad0 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:751 rcu_read_lock include/linux/rcupdate.h:868 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xa86/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6876 tomoyo_path_number_perm+0x470/0x580 security/tomoyo/file.c:736 security_file_ioctl+0x9b/0x240 security/security.c:2435 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0xb7/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] input_inject_event+0x9f/0x3b0 drivers/input/input.c:419 __led_set_brightness drivers/leds/led-core.c:52 [inline] led_set_brightness_nopm drivers/leds/led-core.c:335 [inline] led_set_brightness_nosleep drivers/leds/led-core.c:369 [inline] led_set_brightness+0x217/0x290 drivers/leds/led-core.c:328 kbd_led_trigger_activate+0xcb/0x110 drivers/tty/vt/keyboard.c:1021 led_trigger_set+0x59a/0xc50 drivers/leds/led-triggers.c:220 led_match_default_trigger drivers/leds/led-triggers.c:277 [inline] led_match_default_trigger drivers/leds/led-triggers.c:271 [inline] led_trigger_set_default drivers/leds/led-triggers.c:300 [inline] led_trigger_set_default+0x1e0/0x2e0 drivers/leds/led-triggers.c:284 led_classdev_register_ext+0x71d/0xa30 drivers/leds/led-class.c:578 led_classdev_register include/linux/leds.h:274 [inline] input_leds_connect+0x552/0x8e0 drivers/input/input-leds.c:145 input_attach_handler.isra.0+0x176/0x250 drivers/input/input.c:994 input_register_device+0xab9/0x11b0 drivers/input/input.c:2378 atkbd_connect+0x5f8/0xa60 drivers/input/keyboard/atkbd.c:1340 serio_connect_driver drivers/input/serio/serio.c:44 [inline] serio_driver_probe+0x7f/0xd0 drivers/input/serio/serio.c:748 call_driver_probe drivers/base/dd.c:581 [inline] really_probe+0x241/0xb20 drivers/base/dd.c:659 __driver_probe_device+0x1de/0x470 drivers/base/dd.c:801 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831 __driver_attach+0x283/0x5e0 drivers/base/dd.c:1225 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383 serio_attach_driver drivers/input/serio/serio.c:777 [inline] serio_handle_event+0x281/0xb30 drivers/input/serio/serio.c:214 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 } ... key at: [] __key.7+0x0/0x40 -> (&client->buffer_lock){....}-{3:3} { INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __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+0x10e/0x9b0 drivers/input/evdev.c:261 evdev_events+0x1bb/0x390 drivers/input/evdev.c:306 input_pass_values+0x74e/0x880 drivers/input/input.c:128 input_event_dispose drivers/input/input.c:342 [inline] input_handle_event+0xf00/0x14d0 drivers/input/input.c:370 input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424 evdev_write+0x457/0x750 drivers/input/evdev.c:528 vfs_write+0x2a0/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] __key.88+0x0/0x40 ... 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+0x10e/0x9b0 drivers/input/evdev.c:261 evdev_events+0x1bb/0x390 drivers/input/evdev.c:306 input_pass_values+0x74e/0x880 drivers/input/input.c:128 input_event_dispose drivers/input/input.c:342 [inline] input_handle_event+0xf00/0x14d0 drivers/input/input.c:370 input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424 evdev_write+0x457/0x750 drivers/input/evdev.c:528 vfs_write+0x2a0/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&new->fa_lock){....}-{3:3} { INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326 fasync_remove_entry+0xb2/0x1e0 fs/fcntl.c:1012 fasync_helper+0xaf/0xd0 fs/fcntl.c:1115 lease_modify+0x232/0x500 fs/locks.c:1455 locks_remove_lease fs/locks.c:2726 [inline] locks_remove_file+0x29e/0x5c0 fs/locks.c:2751 __fput+0x351/0xb70 fs/file_table.c:460 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1135 [inline] kill_fasync fs/fcntl.c:1159 [inline] kill_fasync+0x138/0x510 fs/fcntl.c:1152 lease_break_callback+0x23/0x30 fs/locks.c:558 __break_lease+0x6cd/0x1800 fs/locks.c:1598 break_lease include/linux/filelock.h:476 [inline] do_dentry_open+0x6e7/0x1590 fs/open.c:953 vfs_open+0x82/0x3f0 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x2078/0x3140 fs/namei.c:4787 do_filp_open+0x20b/0x470 fs/namei.c:4814 do_sys_openat2+0x121/0x290 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_open fs/open.c:1444 [inline] __se_sys_open fs/open.c:1440 [inline] __x64_sys_open+0x153/0x1e0 fs/open.c:1440 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] __key.0+0x0/0x40 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1135 [inline] kill_fasync fs/fcntl.c:1159 [inline] kill_fasync+0x138/0x510 fs/fcntl.c:1152 __pass_event drivers/input/evdev.c:240 [inline] evdev_pass_values+0x619/0x9b0 drivers/input/evdev.c:278 evdev_events+0x1bb/0x390 drivers/input/evdev.c:306 input_pass_values+0x74e/0x880 drivers/input/input.c:128 input_event_dispose drivers/input/input.c:342 [inline] input_handle_event+0xf00/0x14d0 drivers/input/input.c:370 input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424 evdev_write+0x457/0x750 drivers/input/evdev.c:528 vfs_write+0x2a0/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> (&f_owner->lock){....}-{3:3} { INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326 __f_setown+0x61/0x3c0 fs/fcntl.c:136 fcntl_dirnotify+0x7b1/0xb60 fs/notify/dnotify/dnotify.c:369 do_fcntl+0x504/0x1660 fs/fcntl.c:538 __do_sys_fcntl fs/fcntl.c:602 [inline] __se_sys_fcntl fs/fcntl.c:587 [inline] __x64_sys_fcntl+0x163/0x200 fs/fcntl.c:587 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 send_sigio+0x31/0x3e0 fs/fcntl.c:918 dnotify_handle_event+0x15e/0x2b0 fs/notify/dnotify/dnotify.c:113 fsnotify_handle_inode_event.isra.0+0x1e2/0x3f0 fs/notify/fsnotify.c:321 fsnotify_handle_event fs/notify/fsnotify.c:376 [inline] send_to_group fs/notify/fsnotify.c:424 [inline] fsnotify+0x13fb/0x1de0 fs/notify/fsnotify.c:641 fsnotify_name include/linux/fsnotify.h:55 [inline] fsnotify_name include/linux/fsnotify.h:48 [inline] fsnotify_dirent include/linux/fsnotify.h:61 [inline] fsnotify_mkdir include/linux/fsnotify.h:404 [inline] vfs_mkdir+0x8ae/0xb60 fs/namei.c:5138 do_mkdirat+0x442/0x5e0 fs/namei.c:5164 __do_sys_mkdirat fs/namei.c:5186 [inline] __se_sys_mkdirat fs/namei.c:5184 [inline] __x64_sys_mkdirat+0x83/0xb0 fs/namei.c:5184 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] __key.1+0x0/0x40 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 send_sigio+0x31/0x3e0 fs/fcntl.c:918 kill_fasync_rcu fs/fcntl.c:1144 [inline] kill_fasync fs/fcntl.c:1159 [inline] kill_fasync+0x214/0x510 fs/fcntl.c:1152 lease_break_callback+0x23/0x30 fs/locks.c:558 __break_lease+0x6cd/0x1800 fs/locks.c:1598 break_lease include/linux/filelock.h:476 [inline] do_dentry_open+0x6e7/0x1590 fs/open.c:953 vfs_open+0x82/0x3f0 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x2078/0x3140 fs/namei.c:4787 do_filp_open+0x20b/0x470 fs/namei.c:4814 do_sys_openat2+0x121/0x290 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_open fs/open.c:1444 [inline] __se_sys_open fs/open.c:1440 [inline] __x64_sys_open+0x153/0x1e0 fs/open.c:1440 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (tasklist_lock){.+.+}-{3:3} { HARDIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 __do_wait+0x105/0x890 kernel/exit.c:1672 do_wait+0x21d/0x570 kernel/exit.c:1716 kernel_wait+0x9f/0x160 kernel/exit.c:1892 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 SOFTIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 __do_wait+0x105/0x890 kernel/exit.c:1672 do_wait+0x21d/0x570 kernel/exit.c:1716 kernel_wait+0x9f/0x160 kernel/exit.c:1892 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326 copy_process+0x4668/0x7430 kernel/fork.c:2367 kernel_clone+0xfc/0x910 kernel/fork.c:2651 user_mode_thread+0xc8/0x110 kernel/fork.c:2727 rest_init+0x23/0x2b0 init/main.c:722 start_kernel+0x3ef/0x4d0 init/main.c:1206 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 __do_wait+0x105/0x890 kernel/exit.c:1672 do_wait+0x21d/0x570 kernel/exit.c:1716 kernel_wait+0x9f/0x160 kernel/exit.c:1892 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 send_sigurg+0xed/0xc80 fs/fcntl.c:978 sk_send_sigurg+0x76/0x360 net/core/sock.c:3669 queue_oob net/unix/af_unix.c:2357 [inline] unix_stream_sendmsg+0xfa3/0x1320 net/unix/af_unix.c:2491 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f stack backtrace: CPU: 0 UID: 0 PID: 14396 Comm: syz.9.2778 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline] check_irq_usage+0x8e6/0xbc0 kernel/locking/lockdep.c:2857 check_prev_add kernel/locking/lockdep.c:3169 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x167f/0x2890 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 send_sigurg+0xed/0xc80 fs/fcntl.c:978 sk_send_sigurg+0x76/0x360 net/core/sock.c:3669 queue_oob net/unix/af_unix.c:2357 [inline] unix_stream_sendmsg+0xfa3/0x1320 net/unix/af_unix.c:2491 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f452438f749 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:00007f4525306038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f45245e5fa0 RCX: 00007f452438f749 RDX: 000000000400c9c1 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f4524413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f45245e6038 R14: 00007f45245e5fa0 R15: 00007ffe6af47548