INFO: task syz.0.43:6012 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.43 state:D stack:28136 pid:6012 ppid:5905 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
blkdev_put+0x100/0x7a0 block/bdev.c:944
blkdev_release+0x84/0x90 block/fops.c:604
__fput+0x221/0x930 fs/file_table.c:384
task_work_run+0x1d4/0x260 kernel/task_work.c:245
get_signal+0x11da/0x1390 kernel/signal.c:2679
arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f74b8f9ce59
RSP: 002b:00007f74b85fe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f74b9216090 RCX: 00007f74b8f9ce59
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f74b9032e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74b9216128 R14: 00007f74b9216090 R15: 00007fff5c02fff8
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5531:
#0: ffff888030be20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
1 lock held by udevd/5914:
#0: ffff888141b994c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:805
1 lock held by udevd/5915:
#0: ffff888021cf34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:805
1 lock held by udevd/5916:
#0: ffff888021d434c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:805
1 lock held by udevd/5917:
#0: ffff888021e304c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:805
1 lock held by syz.0.43/6012:
#0: ffff888141b994c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:944
1 lock held by syz.1.55/6050:
#0: ffff888021cf34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:944
1 lock held by syz.2.72/6101:
#0: ffff888021d434c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:944
1 lock held by syz.3.130/6245:
#0: ffff888021e304c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:944
1 lock held by syz.4.142/6291:
#0: ffff888021d57198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x134/0xf10 drivers/block/nbd.c:1563
1 lock held by syz.4.142/6292:
#0: ffff888021d57198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x134/0xf10 drivers/block/nbd.c:1563
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 59 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0xe4a/0x7d80 kernel/locking/lockdep.c:5120
Code: 00 00 84 c9 0f 84 60 0a 00 00 48 89 d8 48 c1 e8 03 42 80 3c 00 00 74 12 48 89 df e8 10 44 77 00 49 b8 00 00 00 00 00 fc ff df <4c> 89 3b 48 8b 44 24 78 42 0f b6 04 00 84 c0 0f 85 a5 0d 00 00 48
RSP: 0018:ffffc900015a77c0 EFLAGS: 00000046
RAX: 1ffff1100365f166 RBX: ffff88801b2f8b30 RCX: ffffffff816815a2
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911bc500
RBP: ffffc900015a7a08 R08: dffffc0000000000 R09: 1ffffffff22378a0
R10: dffffc0000000000 R11: fffffbfff22378a1 R12: 0000000000000000
R13: ffff88801b2f8000 R14: ffff88801b2f8ad0 R15: 86a5e2a755741a0c
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5019e9cff8 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
<TASK>
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x600 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>