===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected syzkaller #0 Not tainted ----------------------------------------------------- syz.1.6927/29502 [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: ffff88802a1a4220 (&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: (&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_event+0x76/0xe0 drivers/input/input.c:395 hidinput_hid_event+0x1471/0x1ed0 drivers/hid/hid-input.c:1752 hid_process_event+0x4be/0x620 drivers/hid/hid-core.c:1565 hid_process_report drivers/hid/hid-core.c:1713 [inline] hid_report_raw_event+0xec2/0x1730 drivers/hid/hid-core.c:2075 __hid_input_report drivers/hid/hid-core.c:2145 [inline] hid_input_report+0x44b/0x580 drivers/hid/hid-core.c:2167 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/0x4650 drivers/usb/gadget/udc/dummy_hcd.c:2005 __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 need_slab_obj_exts mm/slub.c:775 [inline] alloc_slab_obj_exts_early mm/slub.c:2270 [inline] allocate_slab+0x1db/0x660 mm/slub.c:3511 new_slab mm/slub.c:3539 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5375 kmalloc_noprof include/linux/slab.h:950 [inline] dummy_urb_enqueue+0x7c/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1277 usb_hcd_submit_urb+0x328/0x1b70 drivers/usb/core/hcd.c:1542 usb_start_wait_urb+0x13f/0x5b0 drivers/usb/core/message.c:62 usb_internal_control_msg drivers/usb/core/message.c:117 [inline] usb_control_msg+0x234/0x3e0 drivers/usb/core/message.c:167 get_bMaxPacketSize0 drivers/usb/core/hub.c:4851 [inline] hub_port_init+0xb1e/0x28d0 drivers/usb/core/hub.c:5047 hub_port_connect drivers/usb/core/hub.c:5496 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x2593/0x4f30 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3288 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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:3288 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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: &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.1.6927/29502: #0: ffff88807e1e29e0 (&u->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] #0: ffff88807e1e29e0 (&u->lock){+.+.}-{3:3}, at: queue_oob+0x1b6/0x4f0 net/unix/af_unix.c:2333 #1: ffff88802a1a4220 (&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: -> (&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_event+0x76/0xe0 drivers/input/input.c:395 hidinput_hid_event+0x1471/0x1ed0 drivers/hid/hid-input.c:1752 hid_process_event+0x4be/0x620 drivers/hid/hid-core.c:1565 hid_process_report drivers/hid/hid-core.c:1713 [inline] hid_report_raw_event+0xec2/0x1730 drivers/hid/hid-core.c:2075 __hid_input_report drivers/hid/hid-core.c:2145 [inline] hid_input_report+0x44b/0x580 drivers/hid/hid-core.c:2167 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/0x4650 drivers/usb/gadget/udc/dummy_hcd.c:2005 __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 need_slab_obj_exts mm/slub.c:775 [inline] alloc_slab_obj_exts_early mm/slub.c:2270 [inline] allocate_slab+0x1db/0x660 mm/slub.c:3511 new_slab mm/slub.c:3539 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5375 kmalloc_noprof include/linux/slab.h:950 [inline] dummy_urb_enqueue+0x7c/0x780 drivers/usb/gadget/udc/dummy_hcd.c:1277 usb_hcd_submit_urb+0x328/0x1b70 drivers/usb/core/hcd.c:1542 usb_start_wait_urb+0x13f/0x5b0 drivers/usb/core/message.c:62 usb_internal_control_msg drivers/usb/core/message.c:117 [inline] usb_control_msg+0x234/0x3e0 drivers/usb/core/message.c:167 get_bMaxPacketSize0 drivers/usb/core/hub.c:4851 [inline] hub_port_init+0xb1e/0x28d0 drivers/usb/core/hub.c:5047 hub_port_connect drivers/usb/core/hub.c:5496 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x2593/0x4f30 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3288 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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] 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:721 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:863 driver_probe_device+0x4f/0x240 drivers/base/dd.c:893 __driver_attach+0x34c/0x640 drivers/base/dd.c:1287 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:3288 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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: [] input_allocate_device.__key.7+0x0/0x20 -> (&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:1545 __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_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 sock_wake_async+0x137/0x160 net/socket.c:-1 sk_wake_async+0x184/0x280 include/net/sock.h:2571 unix_release_sock+0x74f/0xc80 net/unix/af_unix.c:712 unix_release+0x92/0xd0 net/unix/af_unix.c:1184 __sock_release net/socket.c:727 [inline] sock_close+0xc3/0x240 net/socket.c:1520 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 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:67 [inline] exit_to_user_mode_loop+0xed/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 } ... 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 mousedev_notify_readers+0x6f1/0xc00 drivers/input/mousedev.c:309 mousedev_event+0x602/0x1320 drivers/input/mousedev.c:394 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_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} { 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 send_sigurg+0x55/0x420 fs/fcntl.c:962 sk_send_sigurg+0x6c/0x2e0 net/core/sock.c:3669 tcp_check_urg+0x200/0x760 net/ipv4/tcp_input.c:6261 tcp_urg+0x15d/0x410 net/ipv4/tcp_input.c:6302 tcp_rcv_established+0xf3a/0x2740 net/ipv4/tcp_input.c:6705 tcp_v4_do_rcv+0xa90/0x1430 net/ipv4/tcp_ipv4.c:1884 tcp_v4_rcv+0x2825/0x31f0 net/ipv4/tcp_ipv4.c:2319 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:6181 [inline] __netif_receive_skb net/core/dev.c:6294 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6645 __napi_poll+0xae/0x340 net/core/dev.c:7709 napi_poll net/core/dev.c:7772 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7929 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:1418 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1465 sock_sendmsg_nosec net/socket.c:792 [inline] __sock_sendmsg net/socket.c:807 [inline] __sys_sendto+0x5de/0x710 net/socket.c:2271 __do_sys_sendto net/socket.c:2278 [inline] __se_sys_sendto net/socket.c:2274 [inline] __ia32_sys_sendto+0xdd/0x100 net/socket.c:2274 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 __f_setown+0x67/0x370 fs/fcntl.c:136 f_setown+0x23a/0x300 fs/fcntl.c:183 do_fcntl+0x6cd/0x1a20 fs/fcntl.c:514 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 kill_fasync_rcu fs/fcntl.c:1144 [inline] kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159 sock_wake_async+0x137/0x160 net/socket.c:-1 sk_wake_async+0x184/0x280 include/net/sock.h:2571 unix_release_sock+0x74f/0xc80 net/unix/af_unix.c:712 unix_release+0x92/0xd0 net/unix/af_unix.c:1184 __sock_release net/socket.c:727 [inline] sock_close+0xc3/0x240 net/socket.c:1520 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 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:67 [inline] exit_to_user_mode_loop+0xed/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 } ... 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 sock_wake_async+0x137/0x160 net/socket.c:-1 sk_wake_async+0x184/0x280 include/net/sock.h:2571 unix_release_sock+0x74f/0xc80 net/unix/af_unix.c:712 unix_release+0x92/0xd0 net/unix/af_unix.c:1184 __sock_release net/socket.c:727 [inline] sock_close+0xc3/0x240 net/socket.c:1520 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 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:67 [inline] exit_to_user_mode_loop+0xed/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 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:3288 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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:3288 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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/0x3cd0 kernel/fork.c:2369 kernel_clone+0x248/0x8e0 kernel/fork.c:2653 user_mode_thread+0x110/0x180 kernel/fork.c:2729 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:3288 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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:2354 unix_stream_sendmsg+0xcb1/0xe80 net/unix/af_unix.c:2488 sock_sendmsg_nosec net/socket.c:792 [inline] __sock_sendmsg net/socket.c:807 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2657 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2711 __sys_sendmmsg+0x2e7/0x4e0 net/socket.c:2793 __compat_sys_sendmmsg net/compat.c:360 [inline] __do_compat_sys_sendmmsg net/compat.c:367 [inline] __se_compat_sys_sendmmsg net/compat.c:364 [inline] __ia32_compat_sys_sendmmsg+0xa2/0xc0 net/compat.c:364 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: 0 UID: 0 PID: 29502 Comm: syz.1.6927 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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:2354 unix_stream_sendmsg+0xcb1/0xe80 net/unix/af_unix.c:2488 sock_sendmsg_nosec net/socket.c:792 [inline] __sock_sendmsg net/socket.c:807 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2657 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2711 __sys_sendmmsg+0x2e7/0x4e0 net/socket.c:2793 __compat_sys_sendmmsg net/compat.c:360 [inline] __do_compat_sys_sendmmsg net/compat.c:367 [inline] __se_compat_sys_sendmmsg net/compat.c:364 [inline] __ia32_compat_sys_sendmmsg+0xa2/0xc0 net/compat.c:364 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: 0023:0xf701ef6c 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 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8 RSP: 002b:00000000f540d50c EFLAGS: 00000206 ORIG_RAX: 0000000000000159 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080006c40 RDX: 0000000000000001 RSI: 0000000000040015 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: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 58 pop %rax 3f: b8 .byte 0xb8