[v6.1] INFO: task hung in function_make
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syzbot
Aug 10, 2026, 7:24:33 PM (6 days ago) Aug 10
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: e4f7d8be268e Linux 6.1.182
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1293f079580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=928d2571b7b4e2de3dc9
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/156843a60452/disk-e4f7d8be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/719d532a0151/vmlinux-e4f7d8be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/12160bc2f9ec/bzImage-e4f7d8be.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+928d25...@syzkaller.appspotmail.com
INFO: task syz.5.4379:23482 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.4379 state:D stack:26672 pid:23482 ppid:4691 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
function_make+0x1ee/0x350 drivers/usb/gadget/configfs.c:634
configfs_mkdir+0x511/0x9e0 fs/configfs/dir.c:1360
vfs_mkdir+0x386/0x570 fs/namei.c:4114
do_mkdirat+0x1d8/0x440 fs/namei.c:4139
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152
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: 0033:0x7f6706d9e0d9
RSP: 002b:00007f6704fb4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f6707026180 RCX: 00007f6706d9e0d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f6706e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6707026218 R14: 00007f6707026180 R15: 00007fff7465f3c8
</TASK>
INFO: task syz.5.4379:23484 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.4379 state:D stack:25664 pid:23484 ppid:4691 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: 0033:0x7f6706d9e0d9
RSP: 002b:00007f6704b91028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6707026270 RCX: 00007f6706d9e0d9
RDX: 0000000000000001 RSI: 0000200000000400 RDI: 0000000000000009
RBP: 00007f6706e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6707026308 R14: 00007f6707026270 R15: 00007fff7465f3c8
</TASK>
INFO: task syz.9.4374:23485 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.4374 state:D stack:28112 pid:23485 ppid:22342 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
rwsem_down_write_slowpath+0xc99/0x1160 kernel/locking/rwsem.c:1189
inode_lock_nested include/linux/fs.h:793 [inline]
filename_create+0x20b/0x450 fs/namei.c:3884
do_mkdirat+0xa5/0x440 fs/namei.c:4129
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152
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: 0033:0x7f485cb9e0d9
RSP: 002b:00007f485d9c5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f485ce25fa0 RCX: 00007f485cb9e0d9
RDX: 00000000000001ff RSI: 0000200000000180 RDI: ffffffffffffff9c
RBP: 00007f485cc35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f485ce26038 R14: 00007f485ce25fa0 R15: 00007ffd73a947e8
</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
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 getty/4030:
#0: ffff88814cf1a098 (&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/0:0/15060:
#0: ffff888145242d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90004877d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888144f91190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888144f91190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff88801e750190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88801e750190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2305
#4: ffff888058043118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff888058043118 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#4: ffff888058043118 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#5: ffffffff8dd00708 (register_mutex#6){+.+.}-{3:3}, at: usb_audio_disconnect+0xd0/0x6f0 sound/usb/card.c:960
#6: ffff888024f6f170 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#6: ffff888024f6f170 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#6: ffff888024f6f170 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#7: ffffffff8dcc62c8 (register_mutex#7){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4f0 sound/core/seq/seq_midi.c:459
4 locks held by syz.5.4379/23482:
#0: ffff888145292460 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
#1: ffff888076018660 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff888076018660 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3884
#2: ffffffff8d7b2f90 (gadget_subsys.su_mutex){+.+.}-{3:3}, at: configfs_mkdir+0x4b5/0x9e0 fs/configfs/dir.c:1358
#3: ffff888054a83310 (&gi->lock){+.+.}-{3:3}, at: function_make+0x1ee/0x350 drivers/usb/gadget/configfs.c:634
8 locks held by syz.5.4379/23484:
#0: ffff88801865e0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888145292460 (sb_writers#20){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff88807c54dc88 (&buffer->mutex#2){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
#3: ffff8880487deb78 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
#3: ffff8880487deb78 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
#4: ffff888054a83310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:277
#5: ffff888144be8dc0 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#5: ffff888144be8dc0 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#5: ffff888144be8dc0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#6: ffff888056785170 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#6: ffff888056785170 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#6: ffff888056785170 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#7: ffffffff8dcc62c8 (register_mutex#7){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4f0 sound/core/seq/seq_midi.c:459
2 locks held by syz.9.4374/23485:
#0: ffff888145292460 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
#1: ffff888076018660 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff888076018660 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3884
=============================================
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 07/24/2026
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: 4590 Comm: kworker/u4:24 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:psi_task_change+0x57/0x240 kernel/sched/psi.c:917
Code: c0 0f 85 16 01 00 00 44 8b 77 14 4c 8d a7 b8 05 00 00 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 20 01 00 00 41 8b 34 24 <85> f6 0f 84 95 00 00 00 4c 8d 8f e8 12 00 00 4d 89 cc 49 c1 ec 03
RSP: 0018:ffffc900055c7af8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 223eb66d4b67fc00
RDX: ffff88802d8b0014 RSI: 0000000000005ab4 RDI: ffff88802d8b0000
RBP: 0000000000000000 R08: ffffffff8fa25048 R09: ffffffff8fa25058
R10: ffffffff8fa25050 R11: ffffffff8fa25043 R12: ffff88802d8b05b8
R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff11005b16002
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b77f900168 CR3: 000000007e6e3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
psi_enqueue kernel/sched/stats.h:143 [inline]
enqueue_task+0x23b/0x280 kernel/sched/core.c:2056
activate_task kernel/sched/core.c:2088 [inline]
ttwu_do_activate+0x1b7/0x320 kernel/sched/core.c:3700
ttwu_queue kernel/sched/core.c:3905 [inline]
try_to_wake_up+0x5dc/0x10b0 kernel/sched/core.c:4228
wake_up_worker kernel/workqueue.c:859 [inline]
process_one_work+0x6da/0x1160 kernel/workqueue.c:2255
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:
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(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 found the following issue on:
HEAD commit: e4f7d8be268e Linux 6.1.182
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1293f079580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=928d2571b7b4e2de3dc9
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/156843a60452/disk-e4f7d8be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/719d532a0151/vmlinux-e4f7d8be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/12160bc2f9ec/bzImage-e4f7d8be.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+928d25...@syzkaller.appspotmail.com
INFO: task syz.5.4379:23482 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.4379 state:D stack:26672 pid:23482 ppid:4691 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
function_make+0x1ee/0x350 drivers/usb/gadget/configfs.c:634
configfs_mkdir+0x511/0x9e0 fs/configfs/dir.c:1360
vfs_mkdir+0x386/0x570 fs/namei.c:4114
do_mkdirat+0x1d8/0x440 fs/namei.c:4139
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152
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: 0033:0x7f6706d9e0d9
RSP: 002b:00007f6704fb4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f6707026180 RCX: 00007f6706d9e0d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f6706e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6707026218 R14: 00007f6707026180 R15: 00007fff7465f3c8
</TASK>
INFO: task syz.5.4379:23484 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.4379 state:D stack:25664 pid:23484 ppid:4691 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: 0033:0x7f6706d9e0d9
RSP: 002b:00007f6704b91028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6707026270 RCX: 00007f6706d9e0d9
RDX: 0000000000000001 RSI: 0000200000000400 RDI: 0000000000000009
RBP: 00007f6706e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6707026308 R14: 00007f6707026270 R15: 00007fff7465f3c8
</TASK>
INFO: task syz.9.4374:23485 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.4374 state:D stack:28112 pid:23485 ppid:22342 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
rwsem_down_write_slowpath+0xc99/0x1160 kernel/locking/rwsem.c:1189
inode_lock_nested include/linux/fs.h:793 [inline]
filename_create+0x20b/0x450 fs/namei.c:3884
do_mkdirat+0xa5/0x440 fs/namei.c:4129
__do_sys_mkdirat fs/namei.c:4154 [inline]
__se_sys_mkdirat fs/namei.c:4152 [inline]
__x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152
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: 0033:0x7f485cb9e0d9
RSP: 002b:00007f485d9c5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f485ce25fa0 RCX: 00007f485cb9e0d9
RDX: 00000000000001ff RSI: 0000200000000180 RDI: ffffffffffffff9c
RBP: 00007f485cc35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f485ce26038 R14: 00007f485ce25fa0 R15: 00007ffd73a947e8
</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
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 getty/4030:
#0: ffff88814cf1a098 (&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/0:0/15060:
#0: ffff888145242d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90004877d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888144f91190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888144f91190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff88801e750190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88801e750190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2305
#4: ffff888058043118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff888058043118 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#4: ffff888058043118 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#5: ffffffff8dd00708 (register_mutex#6){+.+.}-{3:3}, at: usb_audio_disconnect+0xd0/0x6f0 sound/usb/card.c:960
#6: ffff888024f6f170 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#6: ffff888024f6f170 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#6: ffff888024f6f170 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#7: ffffffff8dcc62c8 (register_mutex#7){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4f0 sound/core/seq/seq_midi.c:459
4 locks held by syz.5.4379/23482:
#0: ffff888145292460 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
#1: ffff888076018660 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff888076018660 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3884
#2: ffffffff8d7b2f90 (gadget_subsys.su_mutex){+.+.}-{3:3}, at: configfs_mkdir+0x4b5/0x9e0 fs/configfs/dir.c:1358
#3: ffff888054a83310 (&gi->lock){+.+.}-{3:3}, at: function_make+0x1ee/0x350 drivers/usb/gadget/configfs.c:634
8 locks held by syz.5.4379/23484:
#0: ffff88801865e0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888145292460 (sb_writers#20){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffff88807c54dc88 (&buffer->mutex#2){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
#3: ffff8880487deb78 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
#3: ffff8880487deb78 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
#4: ffff888054a83310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:277
#5: ffff888144be8dc0 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#5: ffff888144be8dc0 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#5: ffff888144be8dc0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#6: ffff888056785170 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#6: ffff888056785170 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#6: ffff888056785170 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
#7: ffffffff8dcc62c8 (register_mutex#7){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4f0 sound/core/seq/seq_midi.c:459
2 locks held by syz.9.4374/23485:
#0: ffff888145292460 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
#1: ffff888076018660 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff888076018660 (&default_group_class[depth - 1]#2/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3884
=============================================
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 07/24/2026
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: 4590 Comm: kworker/u4:24 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:psi_task_change+0x57/0x240 kernel/sched/psi.c:917
Code: c0 0f 85 16 01 00 00 44 8b 77 14 4c 8d a7 b8 05 00 00 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 20 01 00 00 41 8b 34 24 <85> f6 0f 84 95 00 00 00 4c 8d 8f e8 12 00 00 4d 89 cc 49 c1 ec 03
RSP: 0018:ffffc900055c7af8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 223eb66d4b67fc00
RDX: ffff88802d8b0014 RSI: 0000000000005ab4 RDI: ffff88802d8b0000
RBP: 0000000000000000 R08: ffffffff8fa25048 R09: ffffffff8fa25058
R10: ffffffff8fa25050 R11: ffffffff8fa25043 R12: ffff88802d8b05b8
R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff11005b16002
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b77f900168 CR3: 000000007e6e3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
psi_enqueue kernel/sched/stats.h:143 [inline]
enqueue_task+0x23b/0x280 kernel/sched/core.c:2056
activate_task kernel/sched/core.c:2088 [inline]
ttwu_do_activate+0x1b7/0x320 kernel/sched/core.c:3700
ttwu_queue kernel/sched/core.c:3905 [inline]
try_to_wake_up+0x5dc/0x10b0 kernel/sched/core.c:4228
wake_up_worker kernel/workqueue.c:859 [inline]
process_one_work+0x6da/0x1160 kernel/workqueue.c:2255
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>
---
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