[v6.1] INFO: task hung in snd_seq_midisynth_remove

1 view
Skip to first unread message

syzbot

unread,
Jul 29, 2026, 9:07:24 AMJul 29
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: dc5c83b7f5f8 Linux 6.1.178
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1757f8c6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=0d260fb6413889183507
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a9aa438e39c2/disk-dc5c83b7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a7b5afd2e170/vmlinux-dc5c83b7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3c7673d370fb/bzImage-dc5c83b7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0d260f...@syzkaller.appspotmail.com

INFO: task syz.3.121:4848 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.121 state:D stack:26160 pid:4848 ppid:4273 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
snd_seq_midisynth_remove+0x68/0x4f0 sound/core/seq/seq_midi.c:459
device_remove drivers/base/dd.c:549 [inline]
__device_release_driver drivers/base/dd.c:1279 [inline]
device_release_driver_internal+0x4cf/0x7c0 drivers/base/dd.c:1305
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3900
snd_seq_device_dev_disconnect+0x39/0x40 sound/core/seq_device.c:182
__snd_device_disconnect sound/core/device.c:63 [inline]
snd_device_disconnect_all+0xcf/0x200 sound/core/device.c:215
snd_card_disconnect+0x385/0x810 sound/core/init.c:538
snd_card_free_when_closed+0x13/0x50 sound/core/init.c:630
f_midi_unbind+0x99/0xf0 drivers/usb/gadget/function/f_midi.c:1335
purge_configs_funcs+0x241/0x3a0 drivers/usb/gadget/configfs.c:1274
configfs_composite_unbind+0xa0/0x1c0 drivers/usb/gadget/configfs.c:1453
gadget_unbind_driver+0x1bb/0x3d0 drivers/usb/gadget/udc/core.c:1702
device_remove drivers/base/dd.c:547 [inline]
__device_release_driver drivers/base/dd.c:1279 [inline]
device_release_driver_internal+0x47d/0x7c0 drivers/base/dd.c:1305
driver_detach+0x1ef/0x2d0 drivers/base/dd.c:1368
bus_remove_driver+0x11c/0x230 drivers/base/bus.c:679
usb_gadget_unregister_driver+0x4a/0x70 drivers/usb/gadget/udc/core.c:1762
unregister_gadget drivers/usb/gadget/configfs.c:253 [inline]
gadget_dev_desc_UDC_store+0x174/0x2e0 drivers/usb/gadget/configfs.c:280
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb49299de99
RSP: 002b:00007fb4937fb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb492c25fa0 RCX: 00007fb49299de99
RDX: 0000000000000001 RSI: 0000200000000700 RDI: 0000000000000008
RBP: 00007fb492a33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb492c26038 R14: 00007fb492c25fa0 R15: 00007ffe6941e228
</TASK>
INFO: task syz.0.141:4922 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.141 state:D stack:26768 pid:4922 ppid:4274 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
device_lock include/linux/device.h:885 [inline]
__device_driver_lock drivers/base/dd.c:1099 [inline]
__driver_attach+0x432/0x6c0 drivers/base/dd.c:1219
bus_for_each_dev+0x182/0x1f0 drivers/base/bus.c:303
bus_add_driver+0x324/0x5d0 drivers/base/bus.c:620
driver_register+0x32d/0x430 drivers/base/driver.c:246
usb_gadget_register_driver_owner+0xf5/0x260 drivers/usb/gadget/udc/core.c:1730
raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:549 [inline]
raw_ioctl+0x13a0/0x3cd0 drivers/usb/gadget/legacy/raw_gadget.c:1262
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff020b9db2b
RSP: 002b:00007ff0219bbf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff020b9db2b
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000003
RBP: 00007ff0219bcfd0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000200000000080 R14: 0000000000000000 R15: 0000000000000000
</TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
6 locks held by kworker/1:1/26:
#0: ffff88801cabf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90000a1fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888145f78190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888145f78190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff888024fad190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff888024fad190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
#4: ffff888024fac118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff888024fac118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
#5: ffffffff8dd00708 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_probe+0x3e7/0x1e70 sound/usb/card.c:812
1 lock held by khungtaskd/28:
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527
2 locks held by kworker/u4:3/47:
2 locks held by getty/4024:
#0: ffff8880305a6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198
8 locks held by kworker/0:4/4279:
#0: ffff88801cabf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90004047d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff88802833a190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff88802833a190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff88807997a190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88807997a190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2305
#4: ffff88801e670118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff88801e670118 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#4: ffff88801e670118 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#5: ffffffff8dd00708 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_disconnect+0xd0/0x6f0 sound/usb/card.c:960
#6: ffff88801e671170 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#6: ffff88801e671170 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#6: ffff88801e671170 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#7: ffffffff8dcc62c8 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4f0 sound/core/seq/seq_midi.c:459
6 locks held by kworker/1:4/4323:
#0: ffff88801cabf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc900046cfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888028438190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888028438190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff88807c201190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88807c201190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
#4: ffff88807e7bd118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff88807e7bd118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
#5: ffffffff8dd00708 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_probe+0x3e7/0x1e70 sound/usb/card.c:812
4 locks held by udevd/4354:
#0: ffff888029b3d2f0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
#1: ffff8880576db488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x59/0x410 fs/kernfs/file.c:172
#2: ffff88801caa7008 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88801caa7008 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173
#3: ffff888024fad190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff888024fad190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16e/0x320 drivers/base/core.c:2669
4 locks held by udevd/4401:
#0: ffff888059272668 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
#1: ffff888030e79c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x59/0x410 fs/kernfs/file.c:172
#2: ffff888047e9f490 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888047e9f490 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173
#3: ffff88807e7bd118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88807e7bd118 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16e/0x320 drivers/base/core.c:2669
8 locks held by syz.3.121/4848:
#0: ffff88807b55e368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888145eaa460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff88807c10e288 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
#3: ffff88802966e978 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
#3: ffff88802966e978 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
#4: ffff88807c3c6310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:277
#5: ffff8881447ccdc0 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#5: ffff8881447ccdc0 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#5: ffff8881447ccdc0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#6: ffff88807d0eb170 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#6: ffff88807d0eb170 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#6: ffff88807d0eb170 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#7: ffffffff8dcc62c8 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4f0 sound/core/seq/seq_midi.c:459
1 lock held by syz.0.141/4922:
#0: ffff8881447ccdc0 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#0: ffff8881447ccdc0 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#0: ffff8881447ccdc0 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x432/0x6c0 drivers/base/dd.c:1219
5 locks held by syz.2.161/4999:
#0: ffff8880789b4d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888145eaa460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff88803019fe88 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
#3: ffff88802966e978 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
#3: ffff88802966e978 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
#4: ffff88807c3c6310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:277
5 locks held by syz.1.174/5062:
#0: ffff8880288c0368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888145eaa460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff88802fde1688 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
#3: ffff88802966e978 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
#3: ffff88802966e978 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
#4: ffff88807c3c6310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:277
6 locks held by kworker/1:11/5508:
#0: ffff88801cabf938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc900035efd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888028470190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888028470190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff888055550190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff888055550190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
#4: ffff88807a19f118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff88807a19f118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
#5: ffffffff8dd00708 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_probe+0x3e7/0x1e70 sound/usb/card.c:812
5 locks held by syz.6.285/5536:
#0: ffff8880242fb9e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888145eaa460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff888073527e88 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
#3: ffff88802966e978 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
#3: ffff88802966e978 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
#4: ffff88807c3c6310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:277

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf0e/0xf50 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 47 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3723 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3743 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3798 [inline]
RIP: 0010:__lock_acquire+0x14c9/0x7c40 kernel/locking/lockdep.c:5063
Code: b8 eb 83 b5 80 46 86 c8 61 49 0f af c6 48 c1 e8 2d 4c 8d 3c c5 80 f1 67 90 4c 89 f8 48 c1 e8 03 48 89 44 24 30 42 80 3c 00 00 <74> 12 4c 89 ff e8 6d 4d 6f 00 49 b8 00 00 00 00 00 fc ff df 49 8b
RSP: 0018:ffffc90000b87560 EFLAGS: 00000046
RAX: 1ffffffff21166ca RBX: 00000000000007c6 RCX: ffffffff816412d5
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90b0f338
RBP: ffffc90000b87790 R08: dffffc0000000000 R09: 1ffffffff2161e67
R10: dffffc0000000000 R11: fffffbfff2161e68 R12: ffff88801d28c6d8
R13: ffff88801d28bc00 R14: 434cbc7c078a74cf R15: ffffffff908b3650
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa593ded2f8 CR3: 000000002a0c8000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
ieee80211_ibss_sta_expire net/mac80211/ibss.c:1256 [inline]
ieee80211_sta_merge_ibss net/mac80211/ibss.c:1299 [inline]
ieee80211_ibss_work+0x580/0x1100 net/mac80211/ibss.c:1708
cfg80211_wiphy_work+0x224/0x260 net/wireless/core.c:433
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

syzbot

unread,
Aug 3, 2026, 3:27:41 AMAug 3
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 6e2fd6534337 Linux 5.15.213
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12aaec9e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=188512c7f571c94b5006
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d7b46606b13d/disk-6e2fd653.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/da120fdeb081/vmlinux-6e2fd653.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3c2643457e3f/bzImage-6e2fd653.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+188512...@syzkaller.appspotmail.com

INFO: task syz.1.411:5634 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.411 state:D stack:25600 pid: 5634 ppid: 4185 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
snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
__device_release_driver drivers/base/dd.c:1249 [inline]
device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
snd_seq_device_dev_disconnect+0x39/0x40 sound/core/seq_device.c:182
__snd_device_disconnect sound/core/device.c:63 [inline]
snd_device_disconnect_all+0xcf/0x200 sound/core/device.c:215
snd_card_disconnect+0x385/0x7d0 sound/core/init.c:528
snd_card_free_when_closed+0x13/0x50 sound/core/init.c:617
f_midi_unbind+0x99/0xf0 drivers/usb/gadget/function/f_midi.c:1291
purge_configs_funcs+0x241/0x3a0 drivers/usb/gadget/configfs.c:1282
configfs_composite_unbind+0xa0/0x1c0 drivers/usb/gadget/configfs.c:1461
usb_gadget_remove_driver+0x15c/0x350 drivers/usb/gadget/udc/core.c:1495
usb_gadget_unregister_driver+0x15d/0x4c0 drivers/usb/gadget/udc/core.c:1654
unregister_gadget drivers/usb/gadget/configfs.c:252 [inline]
gadget_dev_desc_UDC_store+0x174/0x2e0 drivers/usb/gadget/configfs.c:279
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x748/0xd70 fs/read_write.c:594
ksys_write+0x153/0x260 fs/read_write.c:647
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: 0033:0x7f0b25019019
RSP: 002b:00007f0b23250028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0b252a1090 RCX: 00007f0b25019019
RDX: 0000000000000001 RSI: 0000200000000b00 RDI: 0000000000000006
RBP: 00007f0b250b000c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0b252a1128 R14: 00007f0b252a1090 R15: 00007ffc2f88a838
</TASK>
INFO: task syz.3.421:5663 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.421 state:D stack:27888 pid: 5663 ppid: 4191 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
usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:549 [inline]
raw_ioctl+0x115e/0x3750 drivers/usb/gadget/legacy/raw_gadget.c:1256
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
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: 0033:0x7f9763d5ccab
RSP: 002b:00007f9761fb2f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f9763d5ccab
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000003
RBP: 00007f9761fb3fd0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000200000000200 R14: 0000000000000000 R15: 0000000000000000
</TASK>
INFO: task syz.4.425:5671 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.425 state:D stack:28976 pid: 5671 ppid: 4196 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
function_make+0x1ee/0x350 drivers/usb/gadget/configfs.c:629
configfs_mkdir+0x511/0x9e0 fs/configfs/dir.c:1360
vfs_mkdir+0x386/0x570 fs/namei.c:4073
do_mkdirat+0x1dd/0x5c0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111
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: 0033:0x7f04a3c85019
RSP: 002b:00007f04a1edd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f04a3f0cfa0 RCX: 00007f04a3c85019
RDX: 00000000000001ff RSI: 0000200000000400 RDI: ffffffffffffff9c
RBP: 00007f04a3d1c00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f04a3f0d038 R14: 00007f04a3f0cfa0 R15: 00007ffc175b4a98
</TASK>

Showing all locks held in the system:
3 locks held by kworker/0:1/13:
#0: ffff88814c270138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc90000d27d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffffffff8d44d488 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4120
1 lock held by khungtaskd/27:
#0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/1:2/1107:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc90005037d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffff888057e26240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x283/0x3380 drivers/net/netdevsim/fib.c:1480
2 locks held by getty/3939:
#0: ffff88802cf8e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
8 locks held by kworker/0:5/4230:
#0: ffff88801bec7d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc9000315fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffff888147e82220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#2: ffff888147e82220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5827
#3: ffff8880741c1220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#3: ffff8880741c1220 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2278
#4: ffff8880741c21a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#4: ffff8880741c21a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
#4: ffff8880741c21a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
#5: ffffffff8d3f5e88 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_disconnect+0xd0/0x6f0 sound/usb/card.c:960
#6: ffff888078b93200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#6: ffff888078b93200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
#6: ffff888078b93200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
#7: ffffffff8d3bd028 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
4 locks held by kworker/u4:8/4370:
2 locks held by kworker/1:8/4509:
#0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc9000338fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
8 locks held by syz.1.411/5634:
#0: ffff888077284d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
#1: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#2: ffff88802b3e3a88 (&buffer->mutex#2){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
#3: ffff88801b58e078 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
#3: ffff88801b58e078 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
#4: ffff88807d3a7310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276
#5: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_unregister_driver+0x56/0x4c0 drivers/usb/gadget/udc/core.c:1651
#6: ffff888024cf3200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#6: ffff888024cf3200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
#6: ffff888024cf3200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
#7: ffffffff8d3bd028 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
1 lock held by syz.3.421/5663:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
4 locks held by syz.4.425/5671:
#0: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
#1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
#1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3843
#2: ffffffff8ceceff0 (gadget_subsys.su_mutex){+.+.}-{3:3}, at: configfs_mkdir+0x4b5/0x9e0 fs/configfs/dir.c:1358
#3: ffff88807d3a7310 (&gi->lock){+.+.}-{3:3}, at: function_make+0x1ee/0x350 drivers/usb/gadget/configfs.c:629
1 lock held by syz.5.431/5759:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.6.427/5838:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.7.436/5927:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.9.440/5948:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.8.446/5972:
#0: ffff888061aa9aa0 (&default_group_class[depth - 1]#2){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
#0: ffff888061aa9aa0 (&default_group_class[depth - 1]#2){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
1 lock held by syz.2.461/6106:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.1.452/6169:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.0.497/6641:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.6.544/6846:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.3.547/6850:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.5.560/6888:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.4.570/6926:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.7.571/6929:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
3 locks held by syz.8.573/6988:
#0: ffff888077279270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
#1: ffff8881473e2460 (sb_writers#21){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#2: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.8.573/6990:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.2.574/7032:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
5 locks held by syz.9.592/7067:
#0: ffff88807899f9f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
#1: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
#2: ffff88803c557088 (&buffer->mutex#2){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
#3: ffff88801b58e078 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
#3: ffff88801b58e078 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
#4: ffff88807d3a7310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276
1 lock held by syz.0.601/7097:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
2 locks held by syz.1.606/7113:
#0: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
#1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
#1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3843
2 locks held by syz.1.606/7114:
#0: ffff88801df24460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
#1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
#1: ffff888061aa9aa0 (&default_group_class[depth - 1]#2){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
1 lock held by syz.6.615/7155:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.3.634/7242:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.7.632/7306:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.4.656/7348:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz.5.658/7352:
#0: ffffffff8ced1ba8 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz-executor/7359:
#0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
#0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.8.670/7397:
#0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845

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

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 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 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729
Reply all
Reply to author
Forward
0 new messages