INFO: task kworker/1:5:5718 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:22008 pid:5718 tgid:5718 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 i2c_del_adapter+0x62d/0x820 drivers/i2c/i2c-core-base.c:1814 release_nodes+0xa5/0x120 drivers/base/devres.c:546 devres_release_group+0x1c2/0x2d0 drivers/base/devres.c:739 hid_device_remove+0x107/0x270 drivers/hid/hid-core.c:2844 device_remove+0xcb/0x180 drivers/base/dd.c:619 __device_release_driver drivers/base/dd.c:1352 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1375 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:657 device_del+0x376/0x9b0 drivers/base/core.c:3895 hid_remove_device drivers/hid/hid-core.c:3025 [inline] hid_destroy_device+0x19c/0x240 drivers/hid/hid-core.c:3047 usbhid_disconnect+0xa0/0xe0 drivers/hid/usbhid/hid-core.c:1475 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:621 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:613 __device_release_driver drivers/base/dd.c:1352 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1375 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:657 device_del+0x376/0x9b0 drivers/base/core.c:3895 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1478 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1d0c/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.1.1065:9898 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1065 state:D stack:26616 pid:9898 tgid:9884 ppid:5607 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820 device_lock include/linux/device.h:1040 [inline] usbdev_open+0x1b6/0x870 drivers/usb/core/devio.c:1054 chrdev_open+0x234/0x6a0 fs/char_dev.c:411 do_dentry_open+0x6d8/0x1660 fs/open.c:947 vfs_open+0x82/0x3f0 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4858 do_file_open+0x20e/0x430 fs/namei.c:4887 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb80a15d60e RSP: 002b:00007fb80b0a7b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb80b0a86c0 RCX: 00007fb80a15d60e RDX: 0000000000000082 RSI: 00007fb80b0a7c00 RDI: ffffffffffffff9c RBP: 00007fb80b0a7c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fb80a416128 R14: 00007fb80a416090 R15: 00007fff1451da08 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 1 lock held by udevd/4977: 2 locks held by getty/5363: #0: ffff8880386510a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 6 locks held by kworker/1:5/5718: #0: ffff888022e89940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc9000471fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffff88802b7bb1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b7bb1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88802b8091d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88802b8091d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336 #4: ffff888037a251a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff888037a251a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #4: ffff888037a251a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1372 #5: ffff88807a629a58 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #5: ffff88807a629a58 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #5: ffff88807a629a58 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1372 2 locks held by kworker/u8:9/6330: #0: ffff88801ebb7140 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc9000805fd08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 1 lock held by syz.1.1065/9898: #0: ffff88802b7bb1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff88802b7bb1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x870 drivers/usb/core/devio.c:1054 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 4977 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:arch_atomic64_add_return arch/x86/include/asm/atomic64_64.h:79 [inline] RIP: 0010:raw_atomic64_sub_return include/linux/atomic/atomic-arch-fallback.h:2913 [inline] RIP: 0010:raw_atomic64_dec_return include/linux/atomic/atomic-arch-fallback.h:3364 [inline] RIP: 0010:raw_atomic_long_dec_return include/linux/atomic/atomic-long.h:698 [inline] RIP: 0010:atomic_long_dec_return include/linux/atomic/atomic-instrumented.h:3767 [inline] RIP: 0010:file_ref_put include/linux/file_ref.h:157 [inline] RIP: 0010:fput+0x3e/0x100 fs/file_table.c:586 Code: 25 7f ff bf 01 00 00 00 e8 af 8d 4b ff be 08 00 00 00 4c 89 e7 e8 32 e3 ec ff 48 c7 c6 ff ff ff ff f0 48 0f c1 b5 58 01 00 00 <48> 8d 5e ff 31 ff 48 89 de e8 34 20 7f ff 48 85 db 78 31 e8 4a 25 RSP: 0018:ffffc900031afb60 EFLAGS: 00000257 RAX: 0000000000000001 RBX: ffff88807c6fba40 RCX: ffffffff82896dae RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff88807c6fbb98 RBP: ffff88807c6fba40 R08: 0000000000000001 R09: ffffed100f8df773 R10: ffff88807c6fbb9f R11: 0000000000000000 R12: ffff88807c6fbb98 R13: ffffffff895568e0 R14: ffff88802db14ae8 R15: ffffffff8cf17240 FS: 00007f7fb5297880(0000) GS:ffff888124373000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f44507ea2f8 CR3: 0000000029f53000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffafffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: ep_item_poll+0x151/0x1f0 fs/eventpoll.c:1060 ep_send_events+0x330/0xbf0 fs/eventpoll.c:1820 ep_try_send_events fs/eventpoll.c:1907 [inline] ep_poll fs/eventpoll.c:1972 [inline] do_epoll_wait+0x4a4/0x1020 fs/eventpoll.c:2464 __do_sys_epoll_wait fs/eventpoll.c:2472 [inline] __se_sys_epoll_wait fs/eventpoll.c:2467 [inline] __x64_sys_epoll_wait+0x194/0x290 fs/eventpoll.c:2467 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7fb4aa7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff3ecef290 EFLAGS: 00000202 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 00007f7fb5297880 RCX: 00007f7fb4aa7407 RDX: 0000000000000008 RSI: 00007fff3ecef3f0 RDI: 000000000000000b RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000bb8 R11: 0000000000000202 R12: 0000000000000000 R13: 000056172f7f5100 R14: 0000000000000001 R15: 0000000000000000