===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected syzkaller #0 Tainted: G L ----------------------------------------------------- syz.0.4358/17983 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff8e40c058 (tasklist_lock){.+.+}-{3:3}, at: send_sigurg+0x12b/0x420 fs/fcntl.c:978 and this task is already holding: ffff888025c59c20 (&f_owner->lock){....}-{3:3}, at: send_sigurg+0x55/0x420 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: (kbd_event_lock){..-.}-{3:3} ... which became SOFTIRQ-irq-safe 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] class_spinlock_constructor include/linux/spinlock.h:586 [inline] kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342 input_event+0x89/0xe0 drivers/input/input.c:396 input_sync include/linux/input.h:464 [inline] creative_sb0540_raw_event+0x38e/0x430 drivers/hid/hid-creative-sb0540.c:179 __hid_input_report drivers/hid/hid-core.c:2139 [inline] hid_input_report+0x41d/0x580 drivers/hid/hid-core.c:2166 hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286 __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657 dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849 hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 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+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 __rht_ptr_rcu include/linux/rhashtable.h:394 [inline] __rhashtable_lookup include/linux/rhashtable.h:637 [inline] rhltable_lookup include/linux/rhashtable.h:740 [inline] sta_info_hash_lookup+0x1a5/0x610 net/mac80211/sta_info.c:199 sta_info_get+0xf4/0x300 net/mac80211/sta_info.c:211 ieee80211_update_sta_info net/mac80211/ibss.c:979 [inline] ieee80211_rx_bss_info net/mac80211/ibss.c:1092 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline] ieee80211_ibss_rx_queued_mgmt+0x113a/0x2cd0 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1748 [inline] ieee80211_iface_work+0x84e/0x1340 net/mac80211/iface.c:1802 cfg80211_wiphy_work+0x2ab/0x4a0 net/wireless/core.c:440 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:436 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:1678 do_wait+0x1e7/0x540 kernel/exit.c:1722 kernel_wait+0xd6/0x1c0 kernel/exit.c:1898 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:436 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: kbd_event_lock --> &f_owner->lock --> tasklist_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(kbd_event_lock); lock(&f_owner->lock); lock(kbd_event_lock); *** DEADLOCK *** 2 locks held by syz.0.4358/17983: #0: ffff88807dec9860 (&u->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] #0: ffff88807dec9860 (&u->lock){+.+.}-{3:3}, at: queue_oob+0x1b6/0x4f0 net/unix/af_unix.c:2331 #1: ffff888025c59c20 (&f_owner->lock){....}-{3:3}, at: send_sigurg+0x55/0x420 fs/fcntl.c:962 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (kbd_event_lock){..-.}-{3:3} { IN-SOFTIRQ-W 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] class_spinlock_constructor include/linux/spinlock.h:586 [inline] kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342 input_event+0x89/0xe0 drivers/input/input.c:396 input_sync include/linux/input.h:464 [inline] creative_sb0540_raw_event+0x38e/0x430 drivers/hid/hid-creative-sb0540.c:179 __hid_input_report drivers/hid/hid-core.c:2139 [inline] hid_input_report+0x41d/0x580 drivers/hid/hid-core.c:2166 hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286 __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657 dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849 hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 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+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 __rht_ptr_rcu include/linux/rhashtable.h:394 [inline] __rhashtable_lookup include/linux/rhashtable.h:637 [inline] rhltable_lookup include/linux/rhashtable.h:740 [inline] sta_info_hash_lookup+0x1a5/0x610 net/mac80211/sta_info.c:199 sta_info_get+0xf4/0x300 net/mac80211/sta_info.c:211 ieee80211_update_sta_info net/mac80211/ibss.c:979 [inline] ieee80211_rx_bss_info net/mac80211/ibss.c:1092 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline] ieee80211_ibss_rx_queued_mgmt+0x113a/0x2cd0 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1748 [inline] ieee80211_iface_work+0x84e/0x1340 net/mac80211/iface.c:1802 cfg80211_wiphy_work+0x2ab/0x4a0 net/wireless/core.c:440 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:436 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] vt_reset_unicode+0x2b/0x1a0 drivers/tty/vt/keyboard.c:2126 reset_vc+0x68/0x1b0 drivers/tty/vt/vt_ioctl.c:966 vc_init+0x70/0x4a0 drivers/tty/vt/vt.c:3721 con_init+0x377/0x6a0 drivers/tty/vt/vt.c:3787 console_init+0x10b/0x4d0 kernel/printk/printk.c:4407 start_kernel+0x22b/0x3d0 init/main.c:1147 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 } ... key at: [] kbd_event_lock+0x18/0xa0 keyboard.c:-1 -> (&tty->flow.lock){....}-{3:3} { 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] start_tty+0x20/0x70 drivers/tty/tty_io.c:793 n_tty_set_termios+0xa7c/0x10c0 drivers/tty/n_tty.c:1848 tty_set_termios+0xdb3/0x1800 drivers/tty/tty_ioctl.c:348 set_termios+0x566/0x710 drivers/tty/tty_ioctl.c:516 tty_mode_ioctl+0x4a6/0x7d0 drivers/tty/tty_ioctl.c:-1 tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [] alloc_tty_struct.__key.35+0x0/0x20 ... acquired at: __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] stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765 kbd_keycode drivers/tty/vt/keyboard.c:1497 [inline] kbd_event+0x2ec1/0x40d0 drivers/tty/vt/keyboard.c:1515 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541 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_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/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+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 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x23c0 kernel/exit.c:976 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 get_signal+0x1284/0x1330 kernel/signal.c:3034 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_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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 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 rxrpc_notify_socket+0x57b/0x5b0 net/rxrpc/recvmsg.c:56 rxrpc_set_call_completion+0x12c/0x1e0 net/rxrpc/call_state.c:28 rxrpc_distribute_error net/rxrpc/peer_event.c:231 [inline] rxrpc_store_error net/rxrpc/peer_event.c:209 [inline] rxrpc_input_error+0xa9d/0x1070 net/rxrpc/peer_event.c:177 rxrpc_io_thread+0xafe/0x37b0 net/rxrpc/io_thread.c:502 kthread+0x388/0x470 kernel/kthread.c:436 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: [] 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 tty_wakeup drivers/tty/tty_io.c:515 [inline] __start_tty+0x18c/0x220 drivers/tty/tty_io.c:777 n_tty_ioctl_helper+0x128/0x4d0 drivers/tty/tty_ioctl.c:959 tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/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+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 generic_add_lease fs/locks.c:1908 [inline] generic_setlease+0xacf/0xff0 fs/locks.c:1984 do_fcntl_add_lease+0x35e/0x470 fs/locks.c:2086 fcntl_setlease+0x123/0x180 fs/locks.c:2111 do_fcntl+0x8b3/0x1a20 fs/fcntl.c:535 __do_sys_fcntl fs/fcntl.c:602 [inline] __se_sys_fcntl+0xc8/0x150 fs/fcntl.c:587 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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 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_sys_open fs/open.c:1380 [inline] __se_sys_open fs/open.c:1376 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 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: __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_sys_open fs/open.c:1380 [inline] __se_sys_open fs/open.c:1376 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/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+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:1678 do_wait+0x1e7/0x540 kernel/exit.c:1722 kernel_wait+0xd6/0x1c0 kernel/exit.c:1898 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:436 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:1678 do_wait+0x1e7/0x540 kernel/exit.c:1722 kernel_wait+0xd6/0x1c0 kernel/exit.c:1898 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:436 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:1678 do_wait+0x1e7/0x540 kernel/exit.c:1722 kernel_wait+0xd6/0x1c0 kernel/exit.c:1898 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:436 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_sigurg+0x12b/0x420 fs/fcntl.c:978 sk_send_sigurg+0x6c/0x2e0 net/core/sock.c:3669 queue_oob+0x42c/0x4f0 net/unix/af_unix.c:2352 unix_stream_sendmsg+0xcb1/0xe80 net/unix/af_unix.c:2486 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f stack backtrace: CPU: 1 UID: 0 PID: 17983 Comm: syz.0.4358 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_sigurg+0x12b/0x420 fs/fcntl.c:978 sk_send_sigurg+0x6c/0x2e0 net/core/sock.c:3669 queue_oob+0x42c/0x4f0 net/unix/af_unix.c:2352 unix_stream_sendmsg+0xcb1/0xe80 net/unix/af_unix.c:2486 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faf4b99c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007faf4c8c1028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007faf4bc15fa0 RCX: 00007faf4b99c799 RDX: 00000000240408c1 RSI: 0000200000000080 RDI: 0000000000000005 RBP: 00007faf4ba32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faf4bc16038 R14: 00007faf4bc15fa0 R15: 00007faf4bd3fa48