INFO: task syz.7.346:9856 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.346       state:D stack:25672 pid:9856  tgid:9835  ppid:8847   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5504 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7228
 __schedule_loop kernel/sched/core.c:7307 [inline]
 rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
 __rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787
 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1827
 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
 rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251
 f2fs_down_write fs/f2fs/f2fs.h:2411 [inline]
 f2fs_down_write_trace+0x34/0x1f0 fs/f2fs/checkpoint.c:180
 f2fs_issue_checkpoint+0x414/0x6f0 fs/f2fs/checkpoint.c:2095
 f2fs_do_sync_file+0xcd6/0x1960 fs/f2fs/file.c:362
 generic_write_sync include/linux/fs.h:2666 [inline]
 f2fs_file_write_iter+0x716/0x24d0 fs/f2fs/file.c:5300
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61e/0xbb0 fs/read_write.c:687
 ksys_write+0x156/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc5ebdbce59
RSP: 002b:00007fc5e9fed028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc5ec036090 RCX: 00007fc5ebdbce59
RDX: 0000000000001006 RSI: 0000200000005b00 RDI: 0000000000000009
RBP: 00007fc5ebe52e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc5ec036128 R14: 00007fc5ec036090 R15: 00007ffc8ecd5288
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 56 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:-1 [inline]
RIP: 0010:rcu_is_watching+0x44/0xb0 kernel/rcu/tree.c:752
Code: 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 47 8d 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 ac a2 84 00 <48> c7 c3 58 1d 6f 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38
RSP: 0018:ffffc9000122f8e0 EFLAGS: 00000046
RAX: 1ffffffff1b1a8fb RBX: 0000000000000001 RCX: 0000000080000002
RDX: 0000000000000001 RSI: ffffffff8ba92a60 RDI: ffffffff8ba92a20
RBP: ffffc9000122fa78 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000245f1c R12: dffffc0000000000
R13: ffffffff8b23faee R14: ffffffff8d8d47d8 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888126242000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f47843c8ff8 CR3: 000000003e02e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 trace_lock_release include/trace/events/lock.h:68 [inline]
 lock_release+0x4b/0x3c0 kernel/locking/lockdep.c:5879
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline]
 _raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:198
 unlock_rt_mutex_safe kernel/locking/rtmutex.c:350 [inline]
 rt_mutex_slowunlock+0x4ee/0xa20 kernel/locking/rtmutex.c:1467
 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline]
 __batadv_dat_purge+0x334/0x400 net/batman-adv/distributed-arp-table.c:186
 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:205
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>