===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected syzkaller #0 Tainted: G L ----------------------------------------------------- syz.9.2284/12682 [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: ffff888076cdefa0 (&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: (&client->buffer_lock){..-.}-{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 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:353 [inline] input_handle_event+0xb29/0x14d0 drivers/input/input.c:370 input_event drivers/input/input.c:396 [inline] input_event+0x8e/0xd0 drivers/input/input.c:391 hidinput_hid_event+0x90b/0x2440 drivers/hid/hid-input.c:1747 hid_process_event+0x4b7/0x5e0 drivers/hid/hid-core.c:1565 hid_process_report drivers/hid/hid-core.c:1713 [inline] hid_report_raw_event+0xa0a/0x1290 drivers/hid/hid-core.c:2074 __hid_input_report.constprop.0+0x33f/0x450 drivers/hid/hid-core.c:2144 hid_irq_in+0x35e/0x870 drivers/hid/usbhid/hid-core.c:286 __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+0x1809/0x3a00 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+0x219/0x8b0 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 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x2cf/0x330 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20a0 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 save_stack+0x160/0x1f0 mm/page_owner.c:156 __set_page_owner+0x91/0x560 mm/page_owner.c:332 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x25f/0x2440 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 folio_alloc_mpol_noprof+0x36/0xe0 mm/mempolicy.c:2435 vma_alloc_folio_noprof+0xed/0x1e0 mm/mempolicy.c:2470 folio_prealloc mm/memory.c:1192 [inline] wp_page_copy mm/memory.c:3680 [inline] do_wp_page+0x2222/0x5690 mm/memory.c:4141 handle_pte_fault mm/memory.c:6250 [inline] __handle_mm_fault+0x1af2/0x2ad0 mm/memory.c:6366 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6535 do_user_addr_fault+0x423/0xda0 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 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:1674 do_wait+0x21d/0x570 kernel/exit.c:1718 kernel_wait+0x9f/0x160 kernel/exit.c:1894 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: &client->buffer_lock --> &f_owner->lock --> tasklist_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(&client->buffer_lock); lock(&f_owner->lock); lock(&client->buffer_lock); *** DEADLOCK *** 2 locks held by syz.9.2284/12682: #0: ffff888030aaa120 (&u->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #0: ffff888030aaa120 (&u->lock){+.+.}-{3:3}, at: queue_oob net/unix/af_unix.c:2336 [inline] #0: ffff888030aaa120 (&u->lock){+.+.}-{3:3}, at: unix_stream_sendmsg+0xd33/0x1320 net/unix/af_unix.c:2491 #1: ffff888076cdefa0 (&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: -> (&client->buffer_lock){..-.}-{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 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:353 [inline] input_handle_event+0xb29/0x14d0 drivers/input/input.c:370 input_event drivers/input/input.c:396 [inline] input_event+0x8e/0xd0 drivers/input/input.c:391 hidinput_hid_event+0x90b/0x2440 drivers/hid/hid-input.c:1747 hid_process_event+0x4b7/0x5e0 drivers/hid/hid-core.c:1565 hid_process_report drivers/hid/hid-core.c:1713 [inline] hid_report_raw_event+0xa0a/0x1290 drivers/hid/hid-core.c:2074 __hid_input_report.constprop.0+0x33f/0x450 drivers/hid/hid-core.c:2144 hid_irq_in+0x35e/0x870 drivers/hid/usbhid/hid-core.c:286 __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+0x1809/0x3a00 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+0x219/0x8b0 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 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x2cf/0x330 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20a0 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 save_stack+0x160/0x1f0 mm/page_owner.c:156 __set_page_owner+0x91/0x560 mm/page_owner.c:332 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x25f/0x2440 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 folio_alloc_mpol_noprof+0x36/0xe0 mm/mempolicy.c:2435 vma_alloc_folio_noprof+0xed/0x1e0 mm/mempolicy.c:2470 folio_prealloc mm/memory.c:1192 [inline] wp_page_copy mm/memory.c:3680 [inline] do_wp_page+0x2222/0x5690 mm/memory.c:4141 handle_pte_fault mm/memory.c:6250 [inline] __handle_mm_fault+0x1af2/0x2ad0 mm/memory.c:6366 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6535 do_user_addr_fault+0x423/0xda0 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 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 -> (&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 __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 } ... 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 generic_add_lease fs/locks.c:1895 [inline] generic_setlease+0xf0f/0x1330 fs/locks.c:1971 kernel_setlease+0x106/0x140 fs/locks.c:2020 vfs_setlease+0x1e8/0x280 fs/locks.c:2053 do_fcntl_add_lease+0x3c4/0x550 fs/locks.c:2074 fcntl_setlease+0xfc/0x180 fs/locks.c:2099 do_fcntl+0x153b/0x1660 fs/fcntl.c:535 __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+0x13d6/0x1dc0 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_create include/linux/fsnotify.h:323 [inline] vfs_create+0x7a8/0x9e0 fs/namei.c:4134 do_mknodat+0x4f2/0x6f0 fs/namei.c:5039 __do_sys_mknodat fs/namei.c:5071 [inline] __se_sys_mknodat fs/namei.c:5068 [inline] __x64_sys_mknodat+0xaf/0xe0 fs/namei.c:5068 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+0x11f/0x280 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:1674 do_wait+0x21d/0x570 kernel/exit.c:1718 kernel_wait+0x9f/0x160 kernel/exit.c:1894 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:1674 do_wait+0x21d/0x570 kernel/exit.c:1718 kernel_wait+0x9f/0x160 kernel/exit.c:1894 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+0x4185/0x74e0 kernel/fork.c:2324 kernel_clone+0xfc/0x910 kernel/fork.c:2608 user_mode_thread+0xc8/0x110 kernel/fork.c:2684 rest_init+0x23/0x2b0 init/main.c:722 start_kernel+0x3f6/0x4d0 init/main.c:1111 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:1674 do_wait+0x21d/0x570 kernel/exit.c:1718 kernel_wait+0x9f/0x160 kernel/exit.c:1894 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:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2583 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2637 __sys_sendmsg+0x16d/0x220 net/socket.c:2669 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: 60928 PID: 12682 Comm: syz.9.2284 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+0x8f9/0xc10 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+0x1558/0x22f0 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:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2583 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2637 __sys_sendmsg+0x16d/0x220 net/socket.c:2669 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: 0033:0x7feb18f8f749 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:00007feb19e2c038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007feb191e5fa0 RCX: 00007feb18f8f749 RDX: 00000000240408c1 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007feb19013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb191e6038 R14: 00007feb191e5fa0 R15: 00007ffef0cd01b8