INFO: task syz.0.2352:10806 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2352 state:D stack:26480 pid:10806 ppid:4275 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747
sync_bdevs+0x1ab/0x320 block/bdev.c:1071
ksys_sync+0xc2/0x170 fs/sync.c:105
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
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: 0033:0x7fa7b899bf79
RSP: 002b:00007fa7b9807028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fa7b8c15fa0 RCX: 00007fa7b899bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa7b8c15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa7b8c16038 R14: 00007fa7b8c15fa0 R15: 00007ffc853210d8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2dfb0 (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: ffffffff8cb2e7d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
3 locks held by kworker/0:1/14:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90000137d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#2: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
3 locks held by kworker/1:0/22:
#0: ffff88801776ad38 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900001c7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffff888027fde190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
#2: ffff888027fde190 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x5560 drivers/usb/core/hub.c:5845
1 lock held by khungtaskd/27:
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/0:2/128:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90002da7d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4024:
#0: ffff88814d484098 (&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+0x429/0x1390 drivers/tty/n_tty.c:2198
1 lock held by udevd/4400:
#0: ffff888024dc04c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832
3 locks held by kworker/u4:8/5047:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000da67d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd39450 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:594
2 locks held by kworker/0:17/5304:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9001d2b7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by syz.0.2352/10806:
#0: ffff888024dc04c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1071
2 locks held by kworker/u4:10/11876:
3 locks held by kworker/0:21/13722:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90004667d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#2: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
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+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: 2943 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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:4723 [inline]
RIP: 0010:__lock_acquire+0x549/0x7d10 kernel/locking/lockdep.c:4999
Code: 81 e3 ff 1f 00 00 41 c1 ed 03 41 81 e5 f8 03 00 00 49 8d bd 40 52 af 90 be 08 00 00 00 e8 5f 17 6f 00 48 0f a3 1d 87 08 4b 0f <73> 1f 48 8d 04 5b c1 e0 06 48 8d 98 00 d1 47 90 48 ba 00 00 00 00
RSP: 0018:ffffc9000d2d7840 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 000000000000002c RCX: ffffffff816449b1
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90af5240
RBP: ffffc9000d2d7a90 R08: ffffffff90af5247 R09: 1ffffffff215ea48
R10: dffffc0000000000 R11: fffffbfff215ea49 R12: ffff88802e83bb80
R13: 0000000000000000 R14: 0000000000000000 R15: 000000000000002c
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b7a6b2f950 CR3: 000000002e7f6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xeb/0x600 net/batman-adv/network-coding.c:719
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295