INFO: task udevd:4373 blocked for more than 143 seconds.
Not tainted 6.1.146-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:26432 pid:4373 ppid:3638 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
device_lock include/linux/device.h:837 [inline]
uevent_show+0x16c/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+0x49b/0xd50 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+0x434/0x920 fs/read_write.c:470
ksys_read+0x143/0x240 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa2c74a7407
RSP: 002b:00007fffb3015140 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fa2c7b91880 RCX: 00007fa2c74a7407
RDX: 0000000000001000 RSI: 000055d70e580020 RDI: 0000000000000008
RBP: 00007fa2c75efff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a
R13: 00007fa2c75efea0 R14: 0000000000000000 R15: 000055d70e58c220
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b7b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2bfd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:2/32:
#0: ffff8880b8e3aa98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545
#1: ffff8880b8e27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x312/0x6d0 kernel/sched/psi.c:987
2 locks held by getty/4029:
#0: ffff88814d2bd098 (&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+0x41b/0x1380 drivers/tty/n_tty.c:2198
6 locks held by kworker/1:6/4322:
#0: ffff88801cefa538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900041f7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffff88802798f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#2: ffff88802798f190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x5210 drivers/usb/core/hub.c:5813
#3: ffff888057dc4190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#3: ffff888057dc4190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990
#4: ffff88805a052118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#4: ffff88805a052118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990
#5: ffffffff8c9d79b0 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xec/0x2a0 kernel/umh.c:218
4 locks held by udevd/4373:
#0: ffff888028f77d58 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182
#1: ffff888056d69c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3b0 fs/kernfs/file.c:154
#2: ffff888024109cb8 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x3b0 fs/kernfs/file.c:155
#3: ffff888057dc4190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#3: ffff888057dc4190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2669
2 locks held by kworker/u4:20/5492:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc9000507fd00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.1.146-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 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+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4291 Comm: kworker/u4:5 Not tainted 6.1.146-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:mark_lock+0x9c/0x320 kernel/locking/lockdep.c:4606
Code: 89 c7 41 81 e7 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 40 d2 ad 90 be 08 00 00 00 e8 8c 41 6d 00 4c 0f a3 3d e4 2e 4a 0f <73> 10 4b 8d 04 7f c1 e0 06 4c 8d b8 00 51 46 90 eb 24 48 c7 c0 20
RSP: 0018:ffffc90004037740 EFLAGS: 00000057
RAX: 0000000000000001 RBX: ffff88802f9d8000 RCX: ffffffff8163a354
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90add318
RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff215ba64
R10: fffffbfff215ba64 R11: 1ffffffff215ba63 R12: 0000000000000100
R13: dffffc0000000000 R14: ffff88802f9d8b30 R15: 00000000000006c7
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1b7ed83178 CR3: 000000007e0cf000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
mark_usage kernel/locking/lockdep.c:4549 [inline]
__lock_acquire+0xd6f/0x7c50 kernel/locking/lockdep.c:5003
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
__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+0xe7/0x3b0 net/batman-adv/network-coding.c:442
batadv_nc_worker+0x365/0x600 net/batman-adv/network-coding.c:722
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295