INFO: task hung in usbdev_open (2)

Status: upstream: reported on 2026/08/07 14:05
Reported-by: syzbot+26249e04d224415f6bd9@syzkaller.appspotmail.com
First crash: 11h34m, last: 11h34m
▶ ▼ Similar bugs (15)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in usbdev_open (3) 1 1 1321d 1321d 0/1 upstream: reported on 2022/12/25 16:08
upstream INFO: task hung in usbdev_open (2) usb 1 syz, C error 3285 5h19m 2047d 0/29 upstream: reported C repro on 2020/12/29 11:48
linux-6.1 INFO: task hung in usbdev_open origin:lts-only 1 syz, C done 3 1167d 1224d 3/3 fixed on 2023/06/28 17:15
linux-4.19 INFO: task hung in usbdev_open (2) 1 2 1720d 1727d 0/1 auto-closed as invalid on 2022/03/21 09:54
linux-5.15 INFO: task hung in usbdev_open origin:lts-only 1 syz, C error 19 685d 1224d 0/3 auto-obsoleted due to no activity on 2024/12/30 11:10
android-6-12 INFO: task hung in usbdev_open origin:upstream 1 syz 63 21d 409d 0/1 premoderation: reported syz repro on 2025/06/24 04:17
linux-6.1 INFO: task hung in usbdev_open (2) 1 1 970d 970d 0/3 auto-obsoleted due to no activity on 2024/03/20 05:29
linux-4.19 INFO: task hung in usbdev_open 1 6 2020d 2107d 0/1 auto-closed as invalid on 2021/05/25 14:21
linux-4.14 INFO: task hung in usbdev_open 1 7 1979d 2118d 0/1 auto-closed as invalid on 2021/07/05 05:59
upstream INFO: task hung in usbdev_open usb 1 2 2509d 2509d 0/29 auto-closed as invalid on 2019/12/23 20:14
linux-6.1 INFO: task hung in usbdev_open (3) 1 1 859d 859d 0/3 auto-obsoleted due to no activity on 2024/07/09 03:03
linux-4.14 INFO: task hung in usbdev_open (2) 1 1 1271d 1271d 0/1 upstream: reported on 2023/02/13 07:50
linux-6.6 INFO: task hung in usbdev_open (2) 1 1 23d 23d 0/2 upstream: reported on 2026/07/15 16:52
linux-6.6 INFO: task hung in usbdev_open 1 4 150d 227d 0/2 auto-obsoleted due to no activity on 2026/06/18 23:09
upstream INFO: task can't die in usbdev_open usb 1 4 2013d 2126d 0/29 auto-closed as invalid on 2021/04/02 18:49

Sample crash report:
INFO: task syz.5.1637:10555 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1637      state:D stack:26800 pid:10555 ppid:  6002 flags:0x00004004
Call Trace:
 <TASK>
 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: 0033:0x7f40410bd90e
RSP: 002b:00007f403f354b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f403f3556c0 RCX: 00007f40410bd90e
RDX: 0000000000000402 RSI: 00007f403f354c00 RDI: ffffffffffffff9c
RBP: 00007f403f354c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f4041385038 R14: 00007f4041384fa0 R15: 00007fff205cb948
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by dhcpcd/3851:
 #0: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695
2 locks held by getty/3942:
 #0: ffff88807f4c1098 (&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+0x594/0x1a50 drivers/tty/n_tty.c:2158
4 locks held by udevd/7889:
 #0: ffff88805e5c8b08 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
 #1: ffff8880610b7888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:112
 #2: ffff88805f89e490 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:113
 #3: ffff88805d8ca220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #3: ffff88805d8ca220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2408
2 locks held by syz-executor/8947:
 #0: ffff888083b160e0 (&type->s_umount_key#85){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
2 locks held by kworker/u4:26/10129:
11 locks held by syz.7.1570/10212:
 #0: ffff8880788225f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888023e72460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffff88805f943c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287
 #3: ffff88802399c188 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #3: ffff88802399c188 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1063 [inline]
 #3: ffff88802399c188 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x85/0x710 drivers/base/dd.c:1279
 #4: ffff888023f7e220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #4: ffff888023f7e220 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #4: ffff888023f7e220 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #5: ffff888023f7f1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #5: ffff888023f7f1a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #5: ffff888023f7f1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #6: ffff8880205b7220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #6: ffff8880205b7220 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2278
 #7: ffff88801f9bf1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #7: ffff88801f9bf1a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #7: ffff88801f9bf1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #8: ffffffff8d3f5e88 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_disconnect+0xd0/0x6f0 sound/usb/card.c:960
 #9: ffff888075e01200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #9: ffff888075e01200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #9: ffff888075e01200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #10: ffffffff8d3bd028 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
6 locks held by kworker/1:10/10312:
 #0: ffff888017b1b538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90001217d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff8881480fe220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #2: ffff8881480fe220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5827
 #3: ffff88805d8ca220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #3: ffff88805d8ca220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:974
 #4: ffff88807b0701a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #4: ffff88807b0701a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:974
 #5: ffffffff8d3f5e88 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_probe+0x3e7/0x1e70 sound/usb/card.c:812
1 lock held by syz.5.1637/10555:
 #0: ffff888023f7e220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #0: ffff888023f7e220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x14e/0x7a0 drivers/usb/core/devio.c:1040
1 lock held by syz.4.1790/11062:
 #0: ffff888023f7e220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #0: ffff888023f7e220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x14e/0x7a0 drivers/usb/core/devio.c:1040
2 locks held by syz-executor/11275:
 #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x98/0x130 kernel/sched/core.c:483
 #1: ffff8880b9027888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x517/0x810 kernel/sched/psi.c:891
2 locks held by kworker/0:20/11374:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000333fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
3 locks held by kworker/0:21/11375:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900014a7d00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88805f83d400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xab0 drivers/net/netdevsim/dev.c:757
1 lock held by syz.1.2274/12628:
 #0: ffff8881480fe220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #0: ffff8881480fe220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x14e/0x7a0 drivers/usb/core/devio.c:1040
8 locks held by syz-executor/12990:
 #0: ffff88807f7d4460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #1: ffff88808dff3088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x500 fs/kernfs/file.c:287
 #2: ffff88802342a3a8 (kn->active#284){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1fd/0x500 fs/kernfs/file.c:288
 #3: ffffffff8cd8aaa8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd3/0x3a0 drivers/net/netdevsim/bus.c:344
 #4: ffff88805f83c178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #4: ffff88805f83c178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #4: ffff88805f83c178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #5: ffff88805f83d400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline]
 #5: ffff88805f83d400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x109/0x230 drivers/net/netdevsim/dev.c:1561
 #6: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381
 #7: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #7: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:347 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:357 [inline]
RIP: 0010:unwind_next_frame+0x8ee/0x1cf0 arch/x86/kernel/unwind_orc.c:539
Code: b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 05 e8 58 08 89 00 48 8b 04 24 4c 8d 78 f8 4c 8b 73 10 48 b8 00 00 00 00 00 fc ff df <48> 8b 4c 24 30 0f b6 04 01 84 c0 0f 85 3d 0f 00 00 83 3b 00 0f 95
RSP: 0018:ffffc90000ce7310 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc90000ce73a8 RCX: dffffc0000000000
RDX: ffffc90000ce77c0 RSI: ffffffff8da0725c RDI: ffffc90000ce73b8
RBP: ffffc90000ce0000 R08: 000000000000000b R09: 0000000000000003
R10: dffffc0000000000 R11: fffff5200019ce81 R12: 1ffffffff1c1f38f
R13: 1ffffffff1c1f38f R14: ffffc90000ce8000 R15: ffffc90000ce77b8
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6bf3c72f8 CR3: 000000007e77a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 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]
 kfree+0xef/0x2a0 mm/slub.c:4564
 ieee80211_bss_info_update+0x842/0xa80 net/mac80211/scan.c:232
 ieee80211_rx_bss_info net/mac80211/ibss.c:1123 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1763/0x2b50 net/mac80211/ibss.c:1643
 ieee80211_iface_process_skb net/mac80211/iface.c:1459 [inline]
 ieee80211_iface_work+0x714/0xc50 net/mac80211/iface.c:1513
 cfg80211_wiphy_work+0x224/0x260 net/wireless/core.c:433
 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
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/07 14:04 linux-5.15.y aabd761612db e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in usbdev_open
* Struck through repros no longer work on HEAD.