INFO: task hung in usb_audio_disconnect

Status: premoderation: reported syz repro on 2026/04/17 22:11
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+cadf30e19b68700cd92b@syzkaller.appspotmail.com
First crash: 108d, last: 87d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/05/23 lts (merge base) e7a3953084a7 syz [report] lost connection to test machine
2026/05/23 upstream (ToT) 79bd2dded182 syz [report] lost connection to test machine
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in usb_audio_disconnect (2) prio:high sound 1 10 101d 132d 0/29 auto-obsoleted due to no activity on 2026/06/13 15:32
upstream INFO: task hung in usb_audio_disconnect sound 1 2 628d 645d 0/29 auto-obsoleted due to no activity on 2025/02/12 05:05
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/05/23 16:03 15m retest repro android16-6.12 log

Sample crash report:
INFO: task kworker/0:1:10 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1     state:D
 stack:0     pid:10    tgid:10    ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6026 [inline]
 __schedule+0x1399/0x1fa0 kernel/sched/core.c:7880
 __schedule_loop kernel/sched/core.c:7961 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7976
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 usb_audio_disconnect+0xd4/0x740 sound/usb/card.c:1039
 usb_unbind_interface+0x2a7/0xa30 drivers/usb/core/driver.c:462
 device_remove drivers/base/dd.c:569 [inline]
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x4c5/0x790 drivers/base/dd.c:1295
 device_release_driver+0x1d/0x30 drivers/base/dd.c:1318
 bus_remove_device+0x359/0x380 drivers/base/bus.c:576
 device_del+0x581/0xd00 drivers/base/core.c:3881
 usb_disable_device+0x3af/0x770 drivers/usb/core/message.c:1476
 usb_disconnect+0x322/0x930 drivers/usb/core/hub.c:2353
 hub_port_connect drivers/usb/core/hub.c:5414 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5714 [inline]
 port_event drivers/usb/core/hub.c:5878 [inline]
 hub_event+0x1c7a/0x4700 drivers/usb/core/hub.c:5960
 process_one_work kernel/workqueue.c:3261 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342
 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task kworker/1:0:31 blocked for more than 123 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D
 stack:0     pid:31    tgid:31    ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6026 [inline]
 __schedule+0x1399/0x1fa0 kernel/sched/core.c:7880
 __schedule_loop kernel/sched/core.c:7961 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7976
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 usb_audio_disconnect+0xd4/0x740 sound/usb/card.c:1039
 usb_unbind_interface+0x2a7/0xa30 drivers/usb/core/driver.c:462
 device_remove drivers/base/dd.c:569 [inline]
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x4c5/0x790 drivers/base/dd.c:1295
 device_release_driver+0x1d/0x30 drivers/base/dd.c:1318
 bus_remove_device+0x359/0x380 drivers/base/bus.c:576
 device_del+0x581/0xd00 drivers/base/core.c:3881
 usb_disable_device+0x3af/0x770 drivers/usb/core/message.c:1476
 usb_disconnect+0x322/0x930 drivers/usb/core/hub.c:2353
 hub_port_connect drivers/usb/core/hub.c:5414 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5714 [inline]
 port_event drivers/usb/core/hub.c:5878 [inline]
 hub_event+0x1c7a/0x4700 drivers/usb/core/hub.c:5960
 process_one_work kernel/workqueue.c:3261 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342
 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task kworker/0:3:376 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3     state:D
 stack:0     pid:376   tgid:376   ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6026 [inline]
 __schedule+0x1399/0x1fa0 kernel/sched/core.c:7880
 __schedule_loop kernel/sched/core.c:7961 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7976
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 usb_audio_disconnect+0xd4/0x740 sound/usb/card.c:1039
 usb_unbind_interface+0x2a7/0xa30 drivers/usb/core/driver.c:462
 device_remove drivers/base/dd.c:569 [inline]
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x4c5/0x790 drivers/base/dd.c:1295
 device_release_driver+0x1d/0x30 drivers/base/dd.c:1318
 bus_remove_device+0x359/0x380 drivers/base/bus.c:576
 device_del+0x581/0xd00 drivers/base/core.c:3881
 usb_disable_device+0x3af/0x770 drivers/usb/core/message.c:1476
 usb_disconnect+0x322/0x930 drivers/usb/core/hub.c:2353
 hub_port_connect drivers/usb/core/hub.c:5414 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5714 [inline]
 port_event drivers/usb/core/hub.c:5878 [inline]
 hub_event+0x1c7a/0x4700 drivers/usb/core/hub.c:5960
 process_one_work kernel/workqueue.c:3261 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342
 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 88ceac27f2f759e3bbd2a088bdce4bdb7d92b188
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xdad/0xf00 kernel/hung_task.c:423
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 413 Comm: kworker/1:4 Not tainted syzkaller #0 88ceac27f2f759e3bbd2a088bdce4bdb7d92b188
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:memset_orig+0x6a/0xb0 arch/x86/lib/memset_64.S:85
Code: 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d8 0f 1f 84 00 00 00 00 00 89 d1 83 e1 38 74 14 c1 e9 03 <66> 0f 1f 44 00 00 ff c9 48 89 07 48 8d 7f 08 75 f5 83 e2 07 74 0a
RSP: 0018:ffffc90000ebddd0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 000000000000000c RCX: 0000000000000001
RDX: 000000000000000c RSI: 0000000000000000 RDI: ffffc90000ebde40
RBP: ffffc90000ebddf0 R08: 0000000000000003 R09: 0000000000000000
R10: ffffc90000ebde40 R11: fffff520001d7bc9 R12: ffffc90000ebde60
R13: 1ffff920001d7bc4 R14: 0000000000000000 R15: ffffc90000ebde40
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8ab8617dac CR3: 000000010c760000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 print_caller kernel/printk/printk.c:1394 [inline]
 info_print_prefix+0x1cc/0x4a0 kernel/printk/printk.c:1418
 record_print_text+0x177/0x450 kernel/printk/printk.c:1465
 printk_get_next_message+0x2ab/0x9e0 kernel/printk/printk.c:3037
 console_emit_next_record kernel/printk/printk.c:3105 [inline]
 console_flush_all+0x3ab/0xac0 kernel/printk/printk.c:3239
 __console_flush_and_unlock kernel/printk/printk.c:3298 [inline]
 console_unlock+0xf8/0x2c0 kernel/printk/printk.c:3338
 vprintk_emit+0x282/0x650 kernel/printk/printk.c:2462
 dev_vprintk_emit+0x359/0x420 drivers/base/core.c:4962
 dev_printk_emit+0xef/0x150 drivers/base/core.c:4973
 __dev_printk+0x17f/0x1b0 drivers/base/core.c:4985
 _dev_err+0x11f/0x180 drivers/base/core.c:5028
 parse_uac2_sample_rate_range+0xa66/0xd30 sound/usb/format.c:398
 parse_audio_format_rates_v2v3+0x303/0x1a30 sound/usb/format.c:619
 parse_audio_format_i+0x6e5/0xee0 sound/usb/format.c:717
 snd_usb_parse_audio_format+0x93/0x750 sound/usb/format.c:795
 snd_usb_get_audioformat_uac12 sound/usb/stream.c:857 [inline]
 __snd_usb_parse_audio_interface+0x1681/0x47d0 sound/usb/stream.c:1202
 snd_usb_parse_audio_interface+0x3e/0xd0 sound/usb/stream.c:1280
 create_standard_audio_quirk+0x63/0x130 sound/usb/quirks.c:101
 snd_usb_create_quirk sound/usb/quirks.c:541 [inline]
 create_composite_quirk+0x220/0x540 sound/usb/quirks.c:49
 snd_usb_create_quirk+0xab/0x130 sound/usb/quirks.c:541
 usb_audio_probe+0xb62/0x1d60 sound/usb/card.c:960
 usb_probe_interface+0x6ac/0xc00 drivers/usb/core/driver.c:400
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x2d8/0x890 drivers/base/dd.c:657
 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799
 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829
 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957
 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459
 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029
 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078
 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534
 device_add+0x80c/0xbf0 drivers/base/core.c:3692
 usb_set_configuration+0x1acf/0x20b0 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0x95/0x160 drivers/usb/core/generic.c:254
 usb_probe_device+0x1d4/0x380 drivers/usb/core/driver.c:295
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x2d8/0x890 drivers/base/dd.c:657
 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799
 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829
 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957
 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459
 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029
 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078
 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534
 device_add+0x80c/0xbf0 drivers/base/core.c:3692
 usb_new_device+0x9f8/0x15b0 drivers/usb/core/hub.c:2703
 hub_port_connect drivers/usb/core/hub.c:5574 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5714 [inline]
 port_event drivers/usb/core/hub.c:5878 [inline]
 hub_event+0x30c6/0x4700 drivers/usb/core/hub.c:5960
 process_one_work kernel/workqueue.c:3261 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342
 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/09 07:18 android16-6.12 5efa9ec22e39 29233ece .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in usb_audio_disconnect
2026/04/17 22:10 android16-6.12 a0dc3e7a8eb4 24ecfc1e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in usb_audio_disconnect
* Struck through repros no longer work on HEAD.