[v6.1] INFO: task hung in i2c_tiny_usb_disconnect
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syzbot
Aug 9, 2026, 7:52:41 AM (8 days ago) Aug 9
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=12625fb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=1b42d67a901c1ac55498
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d44149580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11877fb9580000
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+1b42d6...@syzkaller.appspotmail.com
INFO: task kworker/0:1:14 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1 state:D stack:23824 pid:14 ppid:2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
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_timeout+0xbd/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x2c2/0x590 kernel/sched/completion.c:138
i2c_del_adapter+0x2c9/0x430 drivers/i2c/i2c-core-base.c:1843
i2c_tiny_usb_disconnect+0x45/0xc0 drivers/i2c/busses/i2c-tiny-usb.c:287
usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
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
usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2314
hub_port_connect drivers/usb/core/hub.c:5361 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
port_event drivers/usb/core/hub.c:5817 [inline]
hub_event+0x1d27/0x5200 drivers/usb/core/hub.c:5899
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
process_scheduled_works kernel/workqueue.c:2355 [inline]
worker_thread+0xd6e/0x12a0 kernel/workqueue.c:2441
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
INFO: task udevd:4316 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:25456 pid:4316 ppid:3639 flags:0x00004002
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]
uevent_show+0x16e/0x320 drivers/base/core.c:2669
dev_attr_show+0x50/0xb0 drivers/base/core.c:2372
sysfs_kf_seq_show+0x349/0x4b0 fs/sysfs/file.c:59
seq_read_iter+0x460/0xc50 fs/seq_file.c:230
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x471/0x960 fs/read_write.c:470
ksys_read+0x14d/0x260 fs/read_write.c:613
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: 0033:0x7efda00a7407
RSP: 002b:00007fff8048b560 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007efd9ffbb880 RCX: 00007efda00a7407
RDX: 0000000000001000 RSI: 000055981e7fea00 RDI: 0000000000000008
RBP: 00007efda01efff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a
R13: 00007efda01efea0 R14: 0000000000000000 R15: 000055981e808ba0
</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
5 locks held by kworker/0:1/14:
#0: ffff888144a70938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90000137d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888028025190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888028025190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff88807c838190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88807c838190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2305
#4: ffff88807c83c118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff88807c83c118 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#4: ffff88807c83c118 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
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/4028:
#0: ffff88814cfcd098 (&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
4 locks held by udevd/4316:
#0: ffff88805c868540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
#1: ffff88807e0ef888
(&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x59/0x410 fs/kernfs/file.c:172
#2: ffff888027515578 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888027515578 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173
#3: ffff88807c838190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88807c838190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16e/0x320 drivers/base/core.c:2669
2 locks held by kworker/1:4/4326:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90003e37d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
5 locks held by kworker/0:9/4360:
#0: ffff888144a70938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90003f87d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888027f56190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888027f56190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff888057ab1190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff888057ab1190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
#4: ffff88801daa0118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff88801daa0118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
6 locks held by kworker/0:12/4364:
#0: ffff888144a70938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90003fc7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888027ec6190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888027ec6190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3200 [inline]
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5413 [inline]
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2076/0x5200 drivers/usb/core/hub.c:5899
#4: ffff888027381b68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5414 [inline]
#4: ffff888027381b68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#4: ffff888027381b68 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#4: ffff888027381b68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x20a1/0x5200 drivers/usb/core/hub.c:5899
#5: ffffffff8d6918b0 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x151/0x18d0 drivers/usb/core/hub.c:3057
1 lock held by syz-executor/4401:
#0: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#0: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
4 locks held by udevd/4491:
#0: ffff888075d8d1c8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
#1: ffff88807c99c888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x59/0x410 fs/kernfs/file.c:172
#2: ffff88807b343660 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88807b343660 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173
#3: ffff888057ab1190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff888057ab1190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16e/0x320 drivers/base/core.c:2669
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4728 [inline]
RIP: 0010:__lock_acquire+0x54c/0x7c40 kernel/locking/lockdep.c:5013
Code: e3 ff 1f 00 00 41 c1 ec 03 41 81 e4 f8 03 00 00 49 8d bc 24 40 02 b1 90 be 08 00 00 00 e8 bc 58 6f 00 48 0f a3 1d 84 fe 4c 0f <73> 1f 48 8d 04 5b c1 e0 06 48 8d 98 00 81 49 90 48 ba 00 00 00 00
RSP: 0018:ffffc90000a5f7a0 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 00000000000006d6 RCX: ffffffff816403b4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90b10318
RBP: ffffc90000a5f9d0 R08: ffffffff90b1031f R09: 1ffffffff2162063
R10: dffffc0000000000 R11: fffffbfff2162064 R12: 00000000000000d8
R13: ffff888019a79e00 R14: 0000000000000000 R15: ffff888019a7a950
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6234e70000 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
batadv_nc_purge_paths+0xe2/0x3a0 net/batman-adv/network-coding.c:442
batadv_nc_worker+0x35f/0x600 net/batman-adv/network-coding.c:722
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.
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syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
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 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=12625fb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=1b42d67a901c1ac55498
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d44149580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11877fb9580000
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+1b42d6...@syzkaller.appspotmail.com
INFO: task kworker/0:1:14 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1 state:D stack:23824 pid:14 ppid:2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
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_timeout+0xbd/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x2c2/0x590 kernel/sched/completion.c:138
i2c_del_adapter+0x2c9/0x430 drivers/i2c/i2c-core-base.c:1843
i2c_tiny_usb_disconnect+0x45/0xc0 drivers/i2c/busses/i2c-tiny-usb.c:287
usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
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
usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2314
hub_port_connect drivers/usb/core/hub.c:5361 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
port_event drivers/usb/core/hub.c:5817 [inline]
hub_event+0x1d27/0x5200 drivers/usb/core/hub.c:5899
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
process_scheduled_works kernel/workqueue.c:2355 [inline]
worker_thread+0xd6e/0x12a0 kernel/workqueue.c:2441
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
INFO: task udevd:4316 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:25456 pid:4316 ppid:3639 flags:0x00004002
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]
uevent_show+0x16e/0x320 drivers/base/core.c:2669
dev_attr_show+0x50/0xb0 drivers/base/core.c:2372
sysfs_kf_seq_show+0x349/0x4b0 fs/sysfs/file.c:59
seq_read_iter+0x460/0xc50 fs/seq_file.c:230
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x471/0x960 fs/read_write.c:470
ksys_read+0x14d/0x260 fs/read_write.c:613
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: 0033:0x7efda00a7407
RSP: 002b:00007fff8048b560 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007efd9ffbb880 RCX: 00007efda00a7407
RDX: 0000000000001000 RSI: 000055981e7fea00 RDI: 0000000000000008
RBP: 00007efda01efff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a
R13: 00007efda01efea0 R14: 0000000000000000 R15: 000055981e808ba0
</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
5 locks held by kworker/0:1/14:
#0: ffff888144a70938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90000137d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888028025190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888028025190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff88807c838190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88807c838190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2305
#4: ffff88807c83c118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff88807c83c118 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1099 [inline]
#4: ffff88807c83c118 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb1/0x7c0 drivers/base/dd.c:1302
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/4028:
#0: ffff88814cfcd098 (&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
4 locks held by udevd/4316:
#0: ffff88805c868540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
#1: ffff88807e0ef888
(&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x59/0x410 fs/kernfs/file.c:172
#2: ffff888027515578 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888027515578 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173
#3: ffff88807c838190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff88807c838190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16e/0x320 drivers/base/core.c:2669
2 locks held by kworker/1:4/4326:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90003e37d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
5 locks held by kworker/0:9/4360:
#0: ffff888144a70938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90003f87d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888027f56190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888027f56190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff888057ab1190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff888057ab1190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
#4: ffff88801daa0118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#4: ffff88801daa0118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:1009
6 locks held by kworker/0:12/4364:
#0: ffff888144a70938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90003fc7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888027ec6190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#2: ffff888027ec6190 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5200 drivers/usb/core/hub.c:5845
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3200 [inline]
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5413 [inline]
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#3: ffff888027f51500 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2076/0x5200 drivers/usb/core/hub.c:5899
#4: ffff888027381b68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5414 [inline]
#4: ffff888027381b68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#4: ffff888027381b68 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#4: ffff888027381b68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x20a1/0x5200 drivers/usb/core/hub.c:5899
#5: ffffffff8d6918b0 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x151/0x18d0 drivers/usb/core/hub.c:3057
1 lock held by syz-executor/4401:
#0: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#0: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
4 locks held by udevd/4491:
#0: ffff888075d8d1c8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x9d/0xc50 fs/seq_file.c:182
#1: ffff88807c99c888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x59/0x410 fs/kernfs/file.c:172
#2: ffff88807b343660 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88807b343660 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173
#3: ffff888057ab1190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:885 [inline]
#3: ffff888057ab1190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16e/0x320 drivers/base/core.c:2669
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4728 [inline]
RIP: 0010:__lock_acquire+0x54c/0x7c40 kernel/locking/lockdep.c:5013
Code: e3 ff 1f 00 00 41 c1 ec 03 41 81 e4 f8 03 00 00 49 8d bc 24 40 02 b1 90 be 08 00 00 00 e8 bc 58 6f 00 48 0f a3 1d 84 fe 4c 0f <73> 1f 48 8d 04 5b c1 e0 06 48 8d 98 00 81 49 90 48 ba 00 00 00 00
RSP: 0018:ffffc90000a5f7a0 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 00000000000006d6 RCX: ffffffff816403b4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90b10318
RBP: ffffc90000a5f9d0 R08: ffffffff90b1031f R09: 1ffffffff2162063
R10: dffffc0000000000 R11: fffffbfff2162064 R12: 00000000000000d8
R13: ffff888019a79e00 R14: 0000000000000000 R15: ffff888019a7a950
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6234e70000 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
batadv_nc_purge_paths+0xe2/0x3a0 net/batman-adv/network-coding.c:442
batadv_nc_worker+0x35f/0x600 net/batman-adv/network-coding.c:722
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>
---
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