===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected syzkaller #0 Not tainted ----------------------------------------------------- syz.8.3535/23415 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff8c00a058 (tasklist_lock){.+.+}-{2:2}, at: send_sigurg+0xcb/0x390 fs/fcntl.c:845 and this task is already holding: ffff8880680083b8 (&f->f_owner.lock){...-}-{2:2}, at: send_sigurg+0x25/0x390 fs/fcntl.c:829 which would create a new lock dependency: (&f->f_owner.lock){...-}-{2:2} -> (tasklist_lock){.+.+}-{2:2} but this new dependency connects a HARDIRQ-irq-safe lock: (&dev->event_lock#2){-...}-{2:2} ... which became HARDIRQ-irq-safe at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 input_event+0x76/0xb0 drivers/input/input.c:456 input_report_key include/linux/input.h:425 [inline] psmouse_report_standard_buttons drivers/input/mouse/psmouse-base.c:123 [inline] psmouse_report_standard_packet+0x4f/0x200 drivers/input/mouse/psmouse-base.c:141 psmouse_process_byte+0x42b/0x620 drivers/input/mouse/psmouse-base.c:232 psmouse_handle_byte+0x43/0x490 drivers/input/mouse/psmouse-base.c:274 psmouse_interrupt+0x699/0x1130 drivers/input/mouse/psmouse-base.c:426 serio_interrupt+0x87/0x130 drivers/input/serio/serio.c:1001 i8042_interrupt+0x363/0x710 drivers/input/serio/i8042.c:606 __handle_irq_event_percpu+0x299/0x9d0 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213 handle_edge_irq+0x243/0xb20 kernel/irq/chip.c:819 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:233 [inline] __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252 common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] default_idle+0xb/0x10 arch/x86/kernel/process.c:729 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21f/0x580 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x330/0x430 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb to a HARDIRQ-irq-unsafe lock: (tasklist_lock){.+.+}-{2:2} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 do_wait+0x293/0xac0 kernel/exit.c:1579 kernel_wait+0xd3/0x1c0 kernel/exit.c:1769 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xb5/0x220 kernel/umh.c:166 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 other info that might help us debug this: Chain exists of: &dev->event_lock#2 --> &f->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->f_owner.lock); lock(&dev->event_lock#2); *** DEADLOCK *** 2 locks held by syz.8.3535/23415: #0: ffff88805c3a3e90 (&u->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline] #0: ffff88805c3a3e90 (&u->lock){+.+.}-{2:2}, at: queue_oob+0x353/0x800 net/unix/af_unix.c:1995 #1: ffff8880680083b8 (&f->f_owner.lock){...-}-{2:2}, at: send_sigurg+0x25/0x390 fs/fcntl.c:829 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&dev->event_lock#2){-...}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 input_event+0x76/0xb0 drivers/input/input.c:456 input_report_key include/linux/input.h:425 [inline] psmouse_report_standard_buttons drivers/input/mouse/psmouse-base.c:123 [inline] psmouse_report_standard_packet+0x4f/0x200 drivers/input/mouse/psmouse-base.c:141 psmouse_process_byte+0x42b/0x620 drivers/input/mouse/psmouse-base.c:232 psmouse_handle_byte+0x43/0x490 drivers/input/mouse/psmouse-base.c:274 psmouse_interrupt+0x699/0x1130 drivers/input/mouse/psmouse-base.c:426 serio_interrupt+0x87/0x130 drivers/input/serio/serio.c:1001 i8042_interrupt+0x363/0x710 drivers/input/serio/i8042.c:606 __handle_irq_event_percpu+0x299/0x9d0 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213 handle_edge_irq+0x243/0xb20 kernel/irq/chip.c:819 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:233 [inline] __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252 common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] default_idle+0xb/0x10 arch/x86/kernel/process.c:729 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21f/0x580 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x330/0x430 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb INITIAL USE at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 input_inject_event+0x9e/0x2c0 drivers/input/input.c:482 led_trigger_event+0x10a/0x1e0 drivers/leds/led-triggers.c:392 kbd_led_trigger_activate+0xb9/0x100 drivers/tty/vt/keyboard.c:1029 led_trigger_set+0x50c/0x910 drivers/leds/led-triggers.c:211 led_trigger_set_default+0x19c/0x1e0 drivers/leds/led-triggers.c:275 led_classdev_register_ext+0x6df/0x8c0 drivers/leds/led-class.c:428 led_classdev_register include/linux/leds.h:196 [inline] input_leds_connect+0x51d/0x750 drivers/input/input-leds.c:139 input_attach_handler drivers/input/input.c:1046 [inline] input_register_device+0xda7/0x1140 drivers/input/input.c:2429 atkbd_connect+0x766/0xa20 drivers/input/keyboard/atkbd.c:1337 serio_connect_driver drivers/input/serio/serio.c:47 [inline] serio_driver_probe+0x76/0x90 drivers/input/serio/serio.c:778 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __driver_attach+0x46b/0x670 drivers/base/dd.c:1164 bus_for_each_dev+0x182/0x1f0 drivers/base/bus.c:303 serio_attach_driver drivers/input/serio/serio.c:807 [inline] serio_handle_event+0x29c/0x840 drivers/input/serio/serio.c:227 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 } ... key at: [] input_allocate_device.__key.6+0x0/0x20 -> (&client->buffer_lock){....}-{2:2} { INITIAL USE at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:364 [inline] evdev_pass_values+0xcb/0xab0 drivers/input/evdev.c:261 evdev_events+0x1c0/0x2f0 drivers/input/evdev.c:306 input_to_handler drivers/input/input.c:126 [inline] input_pass_values+0x87e/0x1210 drivers/input/input.c:156 input_handle_event+0xb3f/0x1490 drivers/input/input.c:415 input_inject_event+0x1b9/0x2c0 drivers/input/input.c:487 evdev_write+0x35b/0x490 drivers/input/evdev.c:530 vfs_write+0x30b/0xd60 fs/read_write.c:592 ksys_write+0x152/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 } ... key at: [] evdev_open.__key.22+0x0/0x20 ... acquired at: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:364 [inline] evdev_pass_values+0xcb/0xab0 drivers/input/evdev.c:261 evdev_events+0x1c0/0x2f0 drivers/input/evdev.c:306 input_to_handler drivers/input/input.c:126 [inline] input_pass_values+0x87e/0x1210 drivers/input/input.c:156 input_handle_event+0xb3f/0x1490 drivers/input/input.c:415 input_inject_event+0x1b9/0x2c0 drivers/input/input.c:487 evdev_write+0x35b/0x490 drivers/input/evdev.c:530 vfs_write+0x30b/0xd60 fs/read_write.c:592 ksys_write+0x152/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> (&new->fa_lock){....}-{2:2} { INITIAL USE at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0xab/0xf0 kernel/locking/spinlock.c:316 fasync_remove_entry+0xf0/0x1c0 fs/fcntl.c:885 sock_fasync+0x84/0xf0 net/socket.c:1370 __fput+0x7c4/0x930 fs/file_table.c:308 task_work_run+0x125/0x1a0 kernel/task_work.c:188 get_signal+0x1222/0x12c0 kernel/signal.c:2672 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 INITIAL READ USE at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline] _raw_read_lock_irqsave+0xb8/0x100 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1008 [inline] kill_fasync+0x16d/0x490 fs/fcntl.c:1029 __pass_event drivers/input/evdev.c:240 [inline] evdev_pass_values+0x54b/0xab0 drivers/input/evdev.c:278 evdev_events+0x1c0/0x2f0 drivers/input/evdev.c:306 input_to_handler drivers/input/input.c:126 [inline] input_pass_values+0x87e/0x1210 drivers/input/input.c:156 input_handle_event+0xb3f/0x1490 drivers/input/input.c:415 input_inject_event+0x1b9/0x2c0 drivers/input/input.c:487 evdev_write+0x35b/0x490 drivers/input/evdev.c:530 vfs_write+0x30b/0xd60 fs/read_write.c:592 ksys_write+0x152/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 } ... key at: [] fasync_insert_entry.__key+0x0/0x20 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline] _raw_read_lock_irqsave+0xb8/0x100 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1008 [inline] kill_fasync+0x16d/0x490 fs/fcntl.c:1029 __pass_event drivers/input/evdev.c:240 [inline] evdev_pass_values+0x54b/0xab0 drivers/input/evdev.c:278 evdev_events+0x1c0/0x2f0 drivers/input/evdev.c:306 input_to_handler drivers/input/input.c:126 [inline] input_pass_values+0x87e/0x1210 drivers/input/input.c:156 input_handle_event+0xb3f/0x1490 drivers/input/input.c:415 input_inject_event+0x1b9/0x2c0 drivers/input/input.c:487 evdev_write+0x35b/0x490 drivers/input/evdev.c:530 vfs_write+0x30b/0xd60 fs/read_write.c:592 ksys_write+0x152/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> (&f->f_owner.lock){...-}-{2:2} { IN-SOFTIRQ-R at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline] _raw_read_lock_irqsave+0xb8/0x100 kernel/locking/spinlock.c:236 send_sigurg+0x25/0x390 fs/fcntl.c:829 sk_send_sigurg+0x6b/0xc0 net/core/sock.c:3137 tcp_check_urg net/ipv4/tcp_input.c:5688 [inline] tcp_urg+0x2bc/0xb20 net/ipv4/tcp_input.c:5729 tcp_rcv_established+0xac2/0x1ce0 net/ipv4/tcp_input.c:6063 tcp_v4_do_rcv+0x44b/0x9b0 net/ipv4/tcp_ipv4.c:1731 tcp_v4_rcv+0x26d8/0x2d10 net/ipv4/tcp_ipv4.c:2143 ip_protocol_deliver_rcu+0x3ad/0x770 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x1d5/0x320 net/ipv4/ip_input.c:231 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5538 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5652 process_backlog+0x370/0x790 net/core/dev.c:6529 __napi_poll+0xc0/0x430 net/core/dev.c:7088 napi_poll net/core/dev.c:7155 [inline] net_rx_action+0x4d4/0xa10 net/core/dev.c:7245 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 __pollwait+0x1be/0x3f0 fs/select.c:233 poll_wait include/linux/poll.h:47 [inline] sock_poll_wait include/net/sock.h:2380 [inline] tcp_poll+0x7b/0xd90 net/ipv4/tcp.c:508 sock_poll+0x34f/0x410 net/socket.c:1333 vfs_poll include/linux/poll.h:94 [inline] do_select+0x100d/0x1790 fs/select.c:537 core_sys_select+0x6fe/0x930 fs/select.c:680 do_pselect fs/select.c:762 [inline] __do_sys_pselect6 fs/select.c:803 [inline] __se_sys_pselect6+0x2f4/0x3c0 fs/select.c:794 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 INITIAL USE at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0xab/0xf0 kernel/locking/spinlock.c:316 __f_setown+0x37/0x330 fs/fcntl.c:91 f_setown_ex fs/fcntl.c:194 [inline] do_fcntl+0x10c4/0x1360 fs/fcntl.c:393 __do_sys_fcntl fs/fcntl.c:466 [inline] __se_sys_fcntl+0xcc/0x190 fs/fcntl.c:451 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 INITIAL READ USE at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline] _raw_read_lock_irqsave+0xb8/0x100 kernel/locking/spinlock.c:236 send_sigurg+0x25/0x390 fs/fcntl.c:829 sk_send_sigurg+0x6b/0xc0 net/core/sock.c:3137 tcp_check_urg net/ipv4/tcp_input.c:5688 [inline] tcp_urg+0x2bc/0xb20 net/ipv4/tcp_input.c:5729 tcp_rcv_established+0xac2/0x1ce0 net/ipv4/tcp_input.c:6063 tcp_v4_do_rcv+0x44b/0x9b0 net/ipv4/tcp_ipv4.c:1731 tcp_v4_rcv+0x26d8/0x2d10 net/ipv4/tcp_ipv4.c:2143 ip_protocol_deliver_rcu+0x3ad/0x770 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x1d5/0x320 net/ipv4/ip_input.c:231 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5538 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5652 process_backlog+0x370/0x790 net/core/dev.c:6529 __napi_poll+0xc0/0x430 net/core/dev.c:7088 napi_poll net/core/dev.c:7155 [inline] net_rx_action+0x4d4/0xa10 net/core/dev.c:7245 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 __pollwait+0x1be/0x3f0 fs/select.c:233 poll_wait include/linux/poll.h:47 [inline] sock_poll_wait include/net/sock.h:2380 [inline] tcp_poll+0x7b/0xd90 net/ipv4/tcp.c:508 sock_poll+0x34f/0x410 net/socket.c:1333 vfs_poll include/linux/poll.h:94 [inline] do_select+0x100d/0x1790 fs/select.c:537 core_sys_select+0x6fe/0x930 fs/select.c:680 do_pselect fs/select.c:762 [inline] __do_sys_pselect6 fs/select.c:803 [inline] __se_sys_pselect6+0x2f4/0x3c0 fs/select.c:794 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 } ... key at: [] __alloc_file.__key+0x0/0x10 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline] _raw_read_lock_irqsave+0xb8/0x100 kernel/locking/spinlock.c:236 send_sigio+0x2f/0x330 fs/fcntl.c:790 kill_fasync_rcu fs/fcntl.c:1015 [inline] kill_fasync+0x20a/0x490 fs/fcntl.c:1029 __pass_event drivers/input/evdev.c:240 [inline] evdev_pass_values+0x54b/0xab0 drivers/input/evdev.c:278 evdev_events+0x1c0/0x2f0 drivers/input/evdev.c:306 input_to_handler drivers/input/input.c:126 [inline] input_pass_values+0x87e/0x1210 drivers/input/input.c:156 input_handle_event+0xb3f/0x1490 drivers/input/input.c:415 input_inject_event+0x1b9/0x2c0 drivers/input/input.c:487 evdev_write+0x35b/0x490 drivers/input/evdev.c:530 vfs_write+0x30b/0xd60 fs/read_write.c:592 ksys_write+0x152/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (tasklist_lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 do_wait+0x293/0xac0 kernel/exit.c:1579 kernel_wait+0xd3/0x1c0 kernel/exit.c:1769 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xb5/0x220 kernel/umh.c:166 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 SOFTIRQ-ON-R at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 do_wait+0x293/0xac0 kernel/exit.c:1579 kernel_wait+0xd3/0x1c0 kernel/exit.c:1769 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xb5/0x220 kernel/umh.c:166 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INITIAL USE at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0xab/0xf0 kernel/locking/spinlock.c:316 copy_process+0x236f/0x3e20 kernel/fork.c:2412 kernel_clone+0x23f/0x990 kernel/fork.c:2679 kernel_thread+0xfa/0x160 kernel/fork.c:2731 rest_init+0x21/0x330 init/main.c:720 start_kernel+0x489/0x540 init/main.c:1154 secondary_startup_64_no_verify+0xb1/0xbb INITIAL READ USE at: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 do_wait+0x293/0xac0 kernel/exit.c:1579 kernel_wait+0xd3/0x1c0 kernel/exit.c:1769 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xb5/0x220 kernel/umh.c:166 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 send_sigurg+0xcb/0x390 fs/fcntl.c:845 sk_send_sigurg+0x6b/0xc0 net/core/sock.c:3137 queue_oob+0x622/0x800 net/unix/af_unix.c:2016 unix_stream_sendmsg+0xb71/0xc90 net/unix/af_unix.c:2116 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499 __sys_sendmmsg+0x2ba/0x500 net/socket.c:2585 __do_sys_sendmmsg net/socket.c:2614 [inline] __se_sys_sendmmsg net/socket.c:2611 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2611 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 stack backtrace: CPU: 1 PID: 23415 Comm: syz.8.3535 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_bad_irq_dependency kernel/locking/lockdep.c:2567 [inline] check_irq_usage kernel/locking/lockdep.c:2806 [inline] check_prev_add kernel/locking/lockdep.c:3057 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x6688/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:228 send_sigurg+0xcb/0x390 fs/fcntl.c:845 sk_send_sigurg+0x6b/0xc0 net/core/sock.c:3137 queue_oob+0x622/0x800 net/unix/af_unix.c:2016 unix_stream_sendmsg+0xb71/0xc90 net/unix/af_unix.c:2116 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499 __sys_sendmmsg+0x2ba/0x500 net/socket.c:2585 __do_sys_sendmmsg net/socket.c:2614 [inline] __se_sys_sendmmsg net/socket.c:2611 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2611 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f21d8102799 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:00007f21d635c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f21d837bfa0 RCX: 00007f21d8102799 RDX: 0000000000000001 RSI: 0000200000011500 RDI: 0000000000000003 RBP: 00007f21d8198bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000040015 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f21d837c038 R14: 00007f21d837bfa0 R15: 00007ffcd51c4138 nf_conntrack: default automatic helper assignment has been turned off for security reasons and CT-based firewall rule not found. Use the iptables CT target to attach helpers instead.