INFO: task syz.2.135:6455 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc3-syzkaller-00079-g87a132e73910 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.135       state:D stack:24048 pid:6455  tgid:6454  ppid:5824   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730
 sync_bdevs+0xfd/0x360 block/bdev.c:1246
 ksys_sync+0xb3/0x150 fs/sync.c:105
 __do_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35a558cde9
RSP: 002b:00007f35a63f0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f35a57a5fa0 RCX: 00007f35a558cde9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f35a57a5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f35a57a5fa0 R15: 00007ffdb36a7538
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/19:
1 lock held by khungtaskd/30:
 #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
2 locks held by getty/5572:
 #0: ffff888031a5e0a0 (&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+0xfba/0x1480 drivers/tty/n_tty.c:2211
1 lock held by udevd/5816:
 #0: ffff888143fa94c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe20 block/bdev.c:903
1 lock held by syz.2.135/6455:
 #0: ffff888143fa94c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1246
1 lock held by syz.3.600/8082:

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-syzkaller-00079-g87a132e73910 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __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:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0xf62/0x12b0 kernel/hung_task.c:399
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6817 Comm: kworker/u8:9 Not tainted 6.14.0-rc3-syzkaller-00079-g87a132e73910 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:hlock_class+0x56/0x130 kernel/locking/lockdep.c:230
Code: 20 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 c0 2c ec 96 e8 c2 4c 87 00 48 0f a3 1d ea 77 56 15 <73> 13 48 69 c3 c8 00 00 00 5b 48 05 e0 30 ec 96 c3 cc cc cc cc 48
RSP: 0018:ffffc9000ceef8e0 EFLAGS: 00000047
RAX: 0000000000000001 RBX: 0000000000000021 RCX: ffffffff8195b4ce
RDX: fffffbfff2dd8599 RSI: 0000000000000008 RDI: ffffffff96ec2cc0
RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff2dd8598
R10: ffffffff96ec2cc7 R11: 0000000000000002 R12: 0000000000000000
R13: ffff88807d04c880 R14: 0000000000000021 R15: ffff88807d04d3c0
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c361796 CR3: 000000000df80000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 check_wait_context kernel/locking/lockdep.c:4852 [inline]
 __lock_acquire+0x410/0x3c40 kernel/locking/lockdep.c:5178
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
 rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0x16a/0x1060 net/batman-adv/network-coding.c:719
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>