INFO: task udevd:5893 blocked for more than 143 seconds.
Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:22600 pid:5893 tgid:5893 ppid:5211 task_flags:0x400140 flags:0x00000002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b88/0x5240 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x163/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746
device_lock include/linux/device.h:922 [inline]
uevent_show+0x17d/0x340 drivers/base/core.c:2730
dev_attr_show+0x55/0xc0 drivers/base/core.c:2424
sysfs_kf_seq_show+0x32b/0x4a0 fs/sysfs/file.c:65
seq_read_iter+0x461/0xda0 fs/seq_file.c:230
new_sync_read fs/read_write.c:489 [inline]
vfs_read+0x9a0/0xb90 fs/read_write.c:570
ksys_read+0x19d/0x2d0 fs/read_write.c:713
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e6df16b6a
RSP: 002b:00007ffc5ca7d268 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00005570b26395c0 RCX: 00007f0e6df16b6a
RDX: 0000000000001000 RSI: 00005570b260f620 RDI: 0000000000000008
RBP: 00005570b26395c0 R08: 0000000000000008 R09: 0000000000000008
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000003fff R14: 00007ffc5ca7d748 R15: 000000000000000a
Showing all locks held in the system:
6 locks held by kworker/0:1/10:
#0: ffff8881412e9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8881412e9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319
#1: ffffc900000f7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900000f7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319
#2: ffff888028961198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#2: ffff888028961198 (&dev->mutex){....}-{4:4}, at: hub_event+0x200/0x50f0 drivers/usb/core/hub.c:5859
#3: ffff88807dcd8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#3: ffff88807dcd8198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x90/0x530 drivers/base/dd.c:1005
#4: ffff88805a0e6160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#4: ffff88805a0e6160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x90/0x530 drivers/base/dd.c:1005
#5: ffffffff8ebe4070 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0x142/0x300 kernel/umh.c:214
2 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764
3 locks held by kworker/1:2/976:
#0: ffff8881412e9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8881412e9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319
#1: ffffc9000399fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000399fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319
#2: ffff888028a3a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#2: ffff888028a3a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x200/0x50f0 drivers/usb/core/hub.c:5859
2 locks held by getty/5596:
#0: ffff888030eb40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000334b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222
4 locks held by udevd/5893:
#0: ffff88802fae4c30 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xda0 fs/seq_file.c:182
#1: ffff88807d298c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154
#2: ffff8880322cb3c8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155
#3: ffff88807dcd8198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#3: ffff88807dcd8198 (&dev->mutex){....}-{4:4}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2730
3 locks held by kworker/0:6/5897:
#0: ffff8881412e9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8881412e9948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319
#1: ffffc900048cfc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900048cfc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319
#2: ffff88814572a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#2: ffff88814572a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x200/0x50f0 drivers/usb/core/hub.c:5859
3 locks held by kworker/u8:9/6122:
#0: ffff8880b8639b18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:613
#1: ffff8880b8623b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41f/0x7a0 kernel/sched/psi.c:987
#2: ffff88807f491c18 (key#17){+...}-{3:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffff88807f491c18 (key#17){+...}-{3:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#2: ffff88807f491c18 (key#17){+...}-{3:3}, at: batadv_nc_process_nc_paths+0xb5/0x3a0 net/batman-adv/network-coding.c:687
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0x1058/0x10a0 kernel/hung_task.c:437
kthread+0x7b7/0x940 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3023 Comm: kworker/u8:7 Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__rcu_read_lock+0x5e/0xb0 kernel/rcu/tree_plugin.h:420
Code: 41 8b 2f ff c5 42 0f b6 04 33 84 c0 75 3e 41 89 2f 42 0f b6 04 33 84 c0 75 49 41 8b 07 3d 00 00 00 40 7d 0b 5b 41 5e 41 5f 5d cc cc cc cc 90 0f 0b 90 eb ef 44 89 f9 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc9000bb37a40 EFLAGS: 00000283
RAX: 0000000000000001 RBX: ffff88805c010d80 RCX: 1ffff11005bf7a48
RDX: 0000000000000000 RSI: 0000000000000063 RDI: ffffffff8ca1b6c0
RBP: ffff88802dfbd240 R08: ffffffff8bfa3791 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88805c010d80
R13: 1ffff1100b802313 R14: ffff88805c7fab18 R15: ffffffff8bfa38e0
FS: 0000000000000000(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd3537fab8 CR3: 0000000033a58000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_read_lock include/linux/rcupdate.h:839 [inline]
batadv_nc_process_nc_paths+0xae/0x3a0 net/batman-adv/network-coding.c:687
batadv_nc_worker+0x42a/0x610 net/batman-adv/network-coding.c:728
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
worker_thread+0x870/0xd50 kernel/workqueue.c:3400
kthread+0x7b7/0x940 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245