INFO: task kworker/1:17:4683 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:17 state:D stack:23024 pid: 4683 ppid: 2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 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+0x2a2/0x450 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+0x664/0x13d0 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+0xac4/0x1090 drivers/net/wireless/ath/ath6kl/core.c:257 ath6kl_usb_probe+0x1302/0x1410 drivers/net/wireless/ath/ath6kl/usb.c:1160 usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396 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 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2223 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293 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 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_new_device+0xd65/0x1660 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+0x2e4a/0x55e0 drivers/usb/core/hub.c:5881 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 INFO: task udevd:5370 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23696 pid: 5370 ppid: 3562 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 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+0xcfc/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:764 [inline] uevent_show+0x17a/0x330 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+0x49b/0xd50 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+0x759/0xd60 fs/read_write.c:485 ksys_read+0x152/0x260 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: 0033:0x7f075958f407 RSP: 002b:00007fff86956d00 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f07594a1880 RCX: 00007f075958f407 RDX: 0000000000001000 RSI: 00005568cc172a00 RDI: 0000000000000008 RBP: 00007f07596d7ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007f07596d7ea0 R14: 0000000000000000 R15: 00005568cc17d350 Showing all locks held in the system: 2 locks held by kworker/u4:0/9: 1 lock held by khungtaskd/27: #0: ffffffff8c31f320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3951: #0: ffff88802c7f8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 2 locks held by kworker/1:8/4292: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90003f2fd00 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 5 locks held by kworker/1:17/4683: #0: ffff888142195538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90002fdfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff888148179220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #2: ffff888148179220 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x55e0 drivers/usb/core/hub.c:5827 #3: ffff88801f471220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #3: ffff88801f471220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:954 #4: ffff88801edd51a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #4: ffff88801edd51a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:954 4 locks held by udevd/5370: #0: ffff88801e4ee8b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff888061d3a088 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112 #2: ffff888064985a00 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113 #3: ffff88801edd51a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #3: ffff88801edd51a8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408 2 locks held by kworker/0:14/6428: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900033ffd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 3 locks held by kworker/0:18/6434: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000373fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8c323da8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #2: ffffffff8c323da8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 3 locks held by kworker/u4:12/7769: 1 lock held by syz.5.1227/10184: #0: ffff888148179220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #0: ffff888148179220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x185/0x7b0 drivers/usb/core/devio.c:1040 1 lock held by syz.6.1231/10229: #0: ffff888148179220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #0: ffff888148179220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x185/0x7b0 drivers/usb/core/devio.c:1040 1 lock held by syz.8.1365/11034: #0: ffff888148179220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #0: ffff888148179220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x185/0x7b0 drivers/usb/core/devio.c:1040 2 locks held by syz-executor/11288: #0: ffff8880204c6118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888147811468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 3 locks held by sed/12173: ============================================= 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 04/18/2026 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+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 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: 9 Comm: kworker/u4:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:206 Code: a4 39 89 7e 65 8b 15 a5 39 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 <83> fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 RSP: 0018:ffffc90000ce7a88 EFLAGS: 00000046 RAX: ffffffff817f61d6 RBX: 0000000000000201 RCX: ffff88813fe90000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: ffffc90000ce7b38 R08: ffff88813fe23207 R09: 1ffff11027fc4640 R10: dffffc0000000000 R11: ffffed1027fc4641 R12: ffffffff8991c0a6 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff9200019cf54 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055961b897950 CR3: 0000000030a5e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000010000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x6/0x80 kernel/trace/trace_preemptirq.c:41 __local_bh_enable_ip+0x136/0x1c0 kernel/softirq.c:406 spin_unlock_bh include/linux/spinlock.h:409 [inline] batadv_nc_purge_paths+0x316/0x3b0 net/batman-adv/network-coding.c:475 batadv_nc_worker+0x327/0x5c0 net/batman-adv/network-coding.c:726 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