===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected syzkaller #0 Tainted: G L ----------------------------------------------------- syz.8.6485/30639 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff8e40c058 (tasklist_lock){.+.+}-{3:3}, at: send_sigio+0x101/0x370 fs/fcntl.c:932 and this task is already holding: ffff88802997bfa0 (&f_owner->lock){....}-{3:3}, at: send_sigio+0x38/0x370 fs/fcntl.c:918 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+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline] input_inject_event+0xa5/0x340 drivers/input/input.c:419 led_trigger_event+0x138/0x210 drivers/leds/led-triggers.c:420 kbd_propagate_led_state drivers/tty/vt/keyboard.c:1065 [inline] kbd_bh+0x1f3/0x300 drivers/tty/vt/keyboard.c:1244 tasklet_action_common+0x2da/0x4b0 kernel/softirq.c:925 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1063 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 to a SOFTIRQ-irq-unsafe lock: (tasklist_lock){.+.+}-{3:3} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 __do_wait+0xde/0x740 kernel/exit.c:1672 do_wait+0x1e7/0x540 kernel/exit.c:1716 kernel_wait+0xd6/0x1c0 kernel/exit.c:1892 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:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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 *** 6 locks held by syz.8.6485/30639: #0: ffff8880348e90b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1255 #1: ffff888083ab2420 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #1: ffff888083ab2420 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684 #2: ffff88807e030940 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #2: ffff88807e030940 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3491 #3: ffffffff9a2e00f8 (&fsnotify_mark_srcu){.+.?}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #3: ffffffff9a2e00f8 (&fsnotify_mark_srcu){.+.?}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #3: ffffffff9a2e00f8 (&fsnotify_mark_srcu){.+.?}-{0:0}, at: fsnotify+0x74c/0x1ae0 fs/notify/fsnotify.c:563 #4: ffff88802814e8d0 (&mark->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] #4: ffff88802814e8d0 (&mark->lock){+.+.}-{3:3}, at: dnotify_handle_event+0x62/0x440 fs/notify/dnotify/dnotify.c:105 #5: ffff88802997bfa0 (&f_owner->lock){....}-{3:3}, at: send_sigio+0x38/0x370 fs/fcntl.c:918 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&dev->event_lock#2){..-.}-{3:3} { IN-SOFTIRQ-W at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline] input_inject_event+0xa5/0x340 drivers/input/input.c:419 led_trigger_event+0x138/0x210 drivers/leds/led-triggers.c:420 kbd_propagate_led_state drivers/tty/vt/keyboard.c:1065 [inline] kbd_bh+0x1f3/0x300 drivers/tty/vt/keyboard.c:1244 tasklet_action_common+0x2da/0x4b0 kernel/softirq.c:925 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1063 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INITIAL USE at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline] input_inject_event+0xa5/0x340 drivers/input/input.c:419 kbd_led_trigger_activate+0xbc/0x100 drivers/tty/vt/keyboard.c:1021 led_trigger_set+0x535/0x960 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+0x787/0x9c0 drivers/leds/led-class.c:578 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:994 [inline] input_register_device+0xd00/0x1160 drivers/input/input.c:2378 atkbd_connect+0x731/0xa50 drivers/input/keyboard/atkbd.c:1340 serio_connect_driver drivers/input/serio/serio.c:44 [inline] serio_driver_probe+0x82/0xd0 drivers/input/serio/serio.c:748 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:661 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:803 driver_probe_device+0x4f/0x240 drivers/base/dd.c:833 __driver_attach+0x3e7/0x710 drivers/base/dd.c:1227 bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:383 serio_attach_driver drivers/input/serio/serio.c:777 [inline] serio_handle_event+0x20a/0xdd0 drivers/input/serio/serio.c:214 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] input_allocate_device.__key.7+0x0/0x20 -> (&client->buffer_lock){....}-{3:3} { INITIAL USE at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:341 [inline] evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261 evdev_events+0x1e6/0x340 drivers/input/evdev.c:306 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342 input_inject_event+0x1dd/0x340 drivers/input/input.c:424 evdev_write+0x325/0x4c0 drivers/input/evdev.c:528 vfs_write+0x29a/0xb90 fs/read_write.c:686 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e } ... key at: [] evdev_open.__key.27+0x0/0x20 ... acquired at: __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:341 [inline] evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261 evdev_events+0x1e6/0x340 drivers/input/evdev.c:306 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342 input_inject_event+0x1dd/0x340 drivers/input/input.c:424 evdev_write+0x325/0x4c0 drivers/input/evdev.c:528 vfs_write+0x29a/0xb90 fs/read_write.c:686 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> (&new->fa_lock){...-}-{3:3} { IN-SOFTIRQ-R at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1135 [inline] kill_fasync+0x199/0x4d0 fs/fcntl.c:1159 sock_wake_async+0x137/0x160 net/socket.c:-1 sk_wake_async_rcu include/net/sock.h:2579 [inline] sock_def_readable+0x3c1/0x580 net/core/sock.c:3613 tcp_data_queue+0x1e2e/0x5e50 net/ipv4/tcp_input.c:5719 tcp_rcv_established+0xf45/0x2740 net/ipv4/tcp_input.c:6710 tcp_v4_do_rcv+0xa90/0x1430 net/ipv4/tcp_ipv4.c:1880 tcp_v4_rcv+0x2825/0x31f0 net/ipv4/tcp_ipv4.c:2315 ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6149 [inline] __netif_receive_skb net/core/dev.c:6262 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6614 __napi_poll+0xae/0x340 net/core/dev.c:7678 napi_poll net/core/dev.c:7741 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7893 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 sk_stream_wait_memory+0x72b/0xf80 net/core/stream.c:149 tcp_sendmsg_locked+0x23ba/0x5490 net/ipv4/tcp.c:1417 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1464 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x627/0x7a0 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __ia32_sys_sendto+0xdd/0x100 net/socket.c:2209 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e INITIAL USE at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline] _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326 fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:1012 sock_fasync+0x85/0xf0 net/socket.c:1480 __fput+0x8a5/0xa70 fs/file_table.c:466 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11eb/0x1330 kernel/signal.c:2807 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __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 include/linux/entry-common.h:325 [inline] __do_fast_syscall_32+0x415/0x640 arch/x86/entry/syscall_32.c:310 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e INITIAL READ USE at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1135 [inline] kill_fasync+0x199/0x4d0 fs/fcntl.c:1159 lease_break_callback+0x26/0x30 fs/locks.c:577 __break_lease+0x81c/0x1e80 fs/locks.c:1657 break_lease include/linux/filelock.h:484 [inline] do_dentry_open+0x1010/0x14e0 fs/open.c:940 vfs_open+0x3b/0x340 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4830 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_compat_sys_open fs/open.c:1425 [inline] __se_compat_sys_open fs/open.c:1423 [inline] __ia32_compat_sys_open+0x117/0x140 fs/open.c:1423 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e } ... key at: [] fasync_insert_entry.__key+0x0/0x20 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1135 [inline] kill_fasync+0x199/0x4d0 fs/fcntl.c:1159 __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+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342 input_inject_event+0x1dd/0x340 drivers/input/input.c:424 evdev_write+0x325/0x4c0 drivers/input/evdev.c:528 vfs_write+0x29a/0xb90 fs/read_write.c:686 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> (&f_owner->lock){....}-{3:3} { INITIAL USE at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline] _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326 __f_setown+0x67/0x370 fs/fcntl.c:136 fcntl_dirnotify+0x3f9/0x6a0 fs/notify/dnotify/dnotify.c:369 do_fcntl+0x77e/0x1a20 fs/fcntl.c:538 do_compat_fcntl64+0x51e/0x7e0 fs/fcntl.c:800 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e INITIAL READ USE at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236 send_sigio+0x38/0x370 fs/fcntl.c:918 dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113 fsnotify_handle_event fs/notify/fsnotify.c:327 [inline] send_to_group fs/notify/fsnotify.c:375 [inline] fsnotify+0x1831/0x1ae0 fs/notify/fsnotify.c:592 fsnotify_name include/linux/fsnotify.h:55 [inline] fsnotify_dirent include/linux/fsnotify.h:61 [inline] fsnotify_mkdir+0x121/0x180 include/linux/fsnotify.h:404 vfs_mkdir+0x45e/0x630 fs/namei.c:5241 filename_mkdirat+0x285/0x510 fs/namei.c:5266 __do_sys_mkdir fs/namei.c:5293 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5290 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e } ... key at: [] file_f_owner_allocate.__key+0x0/0x20 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236 send_sigio+0x38/0x370 fs/fcntl.c:918 kill_fasync_rcu fs/fcntl.c:1144 [inline] kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159 lease_break_callback+0x26/0x30 fs/locks.c:577 __break_lease+0x81c/0x1e80 fs/locks.c:1657 break_lease include/linux/filelock.h:484 [inline] do_dentry_open+0x1010/0x14e0 fs/open.c:940 vfs_open+0x3b/0x340 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4830 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_compat_sys_open fs/open.c:1425 [inline] __se_compat_sys_open fs/open.c:1423 [inline] __ia32_compat_sys_open+0x117/0x140 fs/open.c:1423 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (tasklist_lock){.+.+}-{3:3} { HARDIRQ-ON-R at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 __do_wait+0xde/0x740 kernel/exit.c:1672 do_wait+0x1e7/0x540 kernel/exit.c:1716 kernel_wait+0xd6/0x1c0 kernel/exit.c:1892 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:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 SOFTIRQ-ON-R at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 __do_wait+0xde/0x740 kernel/exit.c:1672 do_wait+0x1e7/0x540 kernel/exit.c:1716 kernel_wait+0xd6/0x1c0 kernel/exit.c:1892 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:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INITIAL USE at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline] _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326 copy_process+0x247a/0x3cf0 kernel/fork.c:2369 kernel_clone+0x248/0x8e0 kernel/fork.c:2654 user_mode_thread+0x110/0x180 kernel/fork.c:2730 rest_init+0x23/0x300 init/main.c:725 start_kernel+0x385/0x3d0 init/main.c:1210 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 INITIAL READ USE at: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 __do_wait+0xde/0x740 kernel/exit.c:1672 do_wait+0x1e7/0x540 kernel/exit.c:1716 kernel_wait+0xd6/0x1c0 kernel/exit.c:1892 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:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 send_sigio+0x101/0x370 fs/fcntl.c:932 dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113 fsnotify_handle_event fs/notify/fsnotify.c:301 [inline] send_to_group fs/notify/fsnotify.c:375 [inline] fsnotify+0x168e/0x1ae0 fs/notify/fsnotify.c:592 __fsnotify_parent+0x50d/0x620 fs/notify/fsnotify.c:238 notify_change+0xc55/0xf40 fs/attr.c:561 __remove_privs fs/inode.c:2314 [inline] file_remove_privs_flags+0x3ba/0x640 fs/inode.c:2335 shmem_file_write_iter+0xa7/0x120 mm/shmem.c:3495 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e stack backtrace: CPU: 1 UID: 0 PID: 30639 Comm: syz.8.6485 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline] check_irq_usage kernel/locking/lockdep.c:2857 [inline] 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+0x2a94/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 send_sigio+0x101/0x370 fs/fcntl.c:932 dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113 fsnotify_handle_event fs/notify/fsnotify.c:301 [inline] send_to_group fs/notify/fsnotify.c:375 [inline] fsnotify+0x168e/0x1ae0 fs/notify/fsnotify.c:592 __fsnotify_parent+0x50d/0x620 fs/notify/fsnotify.c:238 notify_change+0xc55/0xf40 fs/attr.c:561 __remove_privs fs/inode.c:2314 [inline] file_remove_privs_flags+0x3ba/0x640 fs/inode.c:2335 shmem_file_write_iter+0xa7/0x120 mm/shmem.c:3495 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf6ffef6c Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 58 b8 77 00 00 00 cd 80 0f 0b 90 90 90 90 90 90 b8 ad RSP: 002b:00000000f53ed50c EFLAGS: 00000206 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000080000080 RDX: 000000000000000b RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 90 nop 1: 85 d2 test %edx,%edx 3: 74 0a je 0xf 5: 89 ce mov %ecx,%esi 7: 81 e6 ff 0f 00 00 and $0xfff,%esi d: 89 32 mov %esi,(%rdx) f: 85 c0 test %eax,%eax 11: 74 05 je 0x18 13: c1 e9 0c shr $0xc,%ecx 16: 89 08 mov %ecx,(%rax) 18: 31 c0 xor %eax,%eax 1a: 5e pop %rsi 1b: 5d pop %rbp 1c: c3 ret 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 58 pop %rax 2f: b8 77 00 00 00 mov $0x77,%eax 34: cd 80 int $0x80 36: 0f 0b ud2 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: b8 .byte 0xb8 3f: ad lods %ds:(%rsi),%eax