INFO: task syz.0.1117:9244 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1117 state:D stack:27656 pid:9244 tgid:9243 ppid:7972 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
bdev_release+0x15a/0x6d0 block/bdev.c:1128
blkdev_release+0x15/0x20 block/fops.c:702
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:227
get_signal+0x1d1/0x26d0 kernel/signal.c:2807
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x41c/0x4e0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f315278ebe9
RSP: 002b:00007f315358f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f31529b5fa0 RCX: 00007f315278ebe9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f3152811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f31529b6038 R14: 00007f31529b5fa0 R15: 00007ffe8a4bd418
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c2860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c2860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c2860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by getty/5610:
#0: ffff888036aec0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by udevd/6217:
#0: ffff888027014358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945
1 lock held by syz.0.1117/9244:
#0: ffff888027014358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1128
1 lock held by syz-executor100/9829:
#0: ffff888027014358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf0e/0x1260 kernel/hung_task.c:491
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
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: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5867 [inline]
RIP: 0010:lock_acquire+0x134/0x350 kernel/locking/lockdep.c:5825
Code: 65 8b 05 d7 91 3f 12 85 c0 0f 85 a2 00 00 00 65 48 8b 05 17 50 3f 12 8b 90 ec 0a 00 00 85 d2 0f 85 8c 00 00 00 9c 8f 04 24 fa <48> c7 c7 11 92 f4 8d e8 d0 e3 fd 09 45 89 e0 89 e9 44 89 ea 65 ff
RSP: 0018:ffffc90000127a40 EFLAGS: 00000046
RAX: ffff88801e298000 RBX: ffffffff8e5c2860 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8b62bad4 RDI: fffffbfff1cb850c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000063 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881246ac000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005643acf1a660 CR3: 000000000e380000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
batadv_nc_process_nc_paths.part.0+0xe4/0x3e0 net/batman-adv/network-coding.c:687
batadv_nc_process_nc_paths net/batman-adv/network-coding.c:679 [inline]
batadv_nc_worker+0xcd3/0x1030 net/batman-adv/network-coding.c:728
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245