INFO: task kworker/0:13:4608 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:13 state:D stack:23312 pid: 4608 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093 do_wait_for_common+0x295/0x460 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 flush_workqueue+0x667/0x1390 kernel/workqueue.c:2882 hif_detach_htc drivers/net/wireless/ath/ath6kl/usb.c:861 [inline] ath6kl_usb_power_off+0x34/0x40 drivers/net/wireless/ath/ath6kl/usb.c:1060 ath6kl_hif_power_off drivers/net/wireless/ath/ath6kl/hif-ops.h:143 [inline] ath6kl_core_init+0xac4/0x10a0 drivers/net/wireless/ath/ath6kl/core.c:257 ath6kl_usb_probe+0x1301/0x1410 drivers/net/wireless/ath/ath6kl/usb.c:1160 usb_probe_interface+0x5be/0xae0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x276/0xc70 drivers/base/dd.c:595 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a7/0x480 drivers/base/dd.c:999 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489 device_add+0xbcf/0x1050 drivers/base/core.c:3427 usb_set_configuration+0x19d5/0x2030 drivers/usb/core/message.c:2223 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238 usb_probe_device+0x126/0x250 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x276/0xc70 drivers/base/dd.c:595 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a7/0x480 drivers/base/dd.c:999 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489 device_add+0xbcf/0x1050 drivers/base/core.c:3427 usb_new_device+0x9f6/0x15d0 drivers/usb/core/hub.c:2632 hub_port_connect drivers/usb/core/hub.c:5497 [inline] hub_port_connect_change drivers/usb/core/hub.c:5637 [inline] port_event drivers/usb/core/hub.c:5799 [inline] hub_event+0x2b8d/0x5260 drivers/usb/core/hub.c:5881 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task udevd:11808 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23856 pid:11808 ppid: 3560 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 device_lock include/linux/device.h:809 [inline] uevent_show+0x16c/0x320 drivers/base/core.c:2408 dev_attr_show+0x50/0xb0 drivers/base/core.c:2110 sysfs_kf_seq_show+0x316/0x4c0 fs/sysfs/file.c:61 seq_read_iter+0x460/0xc50 fs/seq_file.c:230 call_read_iter include/linux/fs.h:2167 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x75e/0xd50 fs/read_write.c:485 ksys_read+0x153/0x260 fs/read_write.c:623 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: 0033:0x7f9debb11407 RSP: 002b:00007fffb16e6290 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f9deba23880 RCX: 00007f9debb11407 RDX: 0000000000001000 RSI: 0000564955a2ae50 RDI: 0000000000000008 RBP: 00007f9debc59ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007f9debc59ea0 R14: 0000000000000000 R15: 0000564955a02280 INFO: task syz.0.1841:12032 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1841 state:D stack:27888 pid:12032 ppid: 4199 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 device_lock include/linux/device.h:809 [inline] usbdev_open+0x14e/0x7a0 drivers/usb/core/devio.c:1040 chrdev_open+0x585/0x5f0 fs/char_dev.c:414 do_dentry_open+0x7f7/0xf90 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2718/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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: 0033:0x7f879015768e RSP: 002b:00007f878e3eeb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f878e3ef6c0 RCX: 00007f879015768e RDX: 0000000000101301 RSI: 00007f878e3eec00 RDI: ffffffffffffff9c RBP: 00007f878e3eec00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f879041f038 R14: 00007f879041efa0 R15: 00007fff13d4c228 Showing all locks held in the system: 2 locks held by kworker/1:1/23: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90000ddfd00 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 1 lock held by khungtaskd/27: #0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3945: #0: ffff88814d068098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 5 locks held by kworker/0:13/4608: #0: ffff88801bd3e938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900039afd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff888148063220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #2: ffff888148063220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5827 #3: ffff888079b4d220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #3: ffff888079b4d220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:974 #4: ffff88802b7c31a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #4: ffff88802b7c31a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:974 4 locks held by udevd/11808: #0: ffff888069351668 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182 #1: ffff88801d4c8c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:112 #2: ffff88801b3a0490 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:113 #3: ffff888079b4d220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #3: ffff888079b4d220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2408 1 lock held by syz.0.1841/12032: #0: ffff888148063220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline] #0: ffff888148063220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x14e/0x7a0 drivers/usb/core/devio.c:1040 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 12385 Comm: kworker/1:21 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events nsim_dev_trap_report_work RIP: 0010:mark_lock+0x1/0x320 kernel/locking/lockdep.c:4552 Code: c1 7c 90 48 c7 c7 c8 21 8b 8d e8 ea 83 60 00 4c 89 f7 41 89 d9 e9 79 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 <41> 57 41 56 41 55 41 54 53 50 89 d5 49 89 f6 48 89 fb 49 bd 00 00 RSP: 0018:ffffc90003cdf990 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff88802082bb80 RCX: ffffffff815d8f84 RDX: 0000000000000002 RSI: ffff88802082c698 RDI: ffff88802082bb80 RBP: ffffc90003cdfa60 R08: ffffffff901e90df R09: 1ffffffff203d21b R10: dffffc0000000000 R11: fffffbfff203d21c R12: ffff88802082c6b8 R13: 0000000000000001 R14: 1ffff110041058cd R15: ffff88802082c698 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c40c13c CR3: 000000004ca21000 CR4: 00000000003506e0 Call Trace: mark_held_locks kernel/locking/lockdep.c:4193 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:4211 [inline] lockdep_hardirqs_on_prepare+0x237/0x7c0 kernel/locking/lockdep.c:4278 trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49 kasan_quarantine_put+0xd4/0x210 mm/kasan/quarantine.c:231 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 nsim_dev_trap_report drivers/net/netdevsim/dev.c:737 [inline] nsim_dev_trap_report_work+0x771/0xab0 drivers/net/netdevsim/dev.c:762 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287