INFO: task syz.2.581:7254 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.581 state:D stack:25728 pid:7254 ppid:4267 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 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
sync_bdevs+0x1ab/0x320 block/bdev.c:1054
ksys_sync+0xb6/0x150 fs/sync.c:105
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
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: 0033:0x7f080378ebe9
RSP: 002b:00007f08045c0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f08039c5fa0 RCX: 00007f080378ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f08039c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f08039c6038 R14: 00007f08039c5fa0 R15: 00007ffdd03f10d8
Showing all locks held in the system:
3 locks held by kworker/u4:1/11:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b370 (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: ffffffff8cb2bb90 (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/28:
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4029:
#0: ffff88814d34f098 (&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
4 locks held by udevd/4376:
#0: ffff88807d4bec30 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182
#1: ffff88802e168888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3b0 fs/kernfs/file.c:154
#2: ffff8880564a3918 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3b0 fs/kernfs/file.c:155
#3: ffff8880555e8190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#3: ffff8880555e8190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2669
1 lock held by udevd/4381:
#0: ffff888144f8c4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:815
1 lock held by syz.2.581/7254:
#0: ffff888144f8c4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1054
1 lock held by syz-executor/7931:
5 locks held by kworker/1:28/8536:
#0: ffff88801bee0538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90003f67d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffff888027726190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#2: ffff888027726190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x54e0 drivers/usb/core/hub.c:5845
#3: ffff8880555e8190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#3: ffff8880555e8190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990
#4: ffff8880555ef118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
#4: ffff8880555ef118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990
5 locks held by syz.3.999/9440:
2 locks held by syz.6.995/9443:
1 lock held by syz.0.1016/9502:
2 locks held by syz.0.1016/9518:
3 locks held by syz.6.1021/9527:
=============================================
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 07/12/2025
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: 11 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lockdep_softirqs_on+0x170/0x570 kernel/locking/lockdep.c:4453
Code: 0f 85 4d 03 00 00 4d 8d b5 78 0a 00 00 41 c7 85 c0 0a 00 00 01 00 00 00 4d 8d bd a0 0a 00 00 4c 89 f8 48 c1 e8 03 80 3c 10 00 <74> 12 4c 89 ff e8 96 27 6e 00 48 ba 00 00 00 00 00 fc ff df 49 89
RSP: 0000:ffffc900001079e0 EFLAGS: 00000046
RAX: 1ffff11027fd48c4 RBX: ffffffff89e1beb6 RCX: afbb4ff490438600
RDX: dffffc0000000000 RSI: ffffffff8a8c0fe0 RDI: ffffffff8adefae0
RBP: ffffc90000107a90 R08: dffffc0000000000 R09: ffffed100fad7051
R10: ffffed100fad7051 R11: 1ffff1100fad7050 R12: 1ffff92000020f40
R13: ffff88813fea3b80 R14: ffff88813fea45f8 R15: ffff88813fea4620
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe2bc2f8704 CR3: 0000000046099000 CR4: 00000000003506f0
DR0: 0001fffffffe0000 DR1: 0100000000000009 DR2: 0000000000000106
DR3: 1000000100000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__local_bh_enable_ip+0xe6/0x1b0 kernel/softirq.c:409
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x316/0x3b0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x324/0x600 net/batman-adv/network-coding.c:720
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