INFO: task syz-executor.2:718 blocked for more than 143 seconds.
      Not tainted 6.3.0-rc2-next-20230316-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:27896 pid:718   ppid:5122   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5305 [inline]
 __schedule+0x1d23/0x5650 kernel/sched/core.c:6623
 schedule+0xde/0x1a0 kernel/sched/core.c:6699
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6758
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0xa3b/0x1350 kernel/locking/mutex.c:747
 eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962
 eventpoll_release include/linux/eventpoll.h:53 [inline]
 __fput+0x7da/0xa90 fs/file_table.c:312
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 get_signal+0x1c7/0x25b0 kernel/signal.c:2635
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f335f28c0f9
RSP: 002b:00007f335ffe9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: 000000000000000b RBX: 00007f335f3abf80 RCX: 00007f335f28c0f9
RDX: 0000000000000318 RSI: 00000000200bd000 RDI: 0000000000000004
RBP: 00007f335f2e7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd61488c5f R14: 00007f335ffe9300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/13:
 #0: ffffffff8c795830 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/14:
 #0: ffffffff8c795530 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffffffff8c796400 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6545
2 locks held by getty/4760:
 #0: ffff88814aec0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177
2 locks held by kworker/u4:24/13162:
 #0: ffff8880b983c518 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2f/0x120 kernel/sched/core.c:539
 #1: ffffc9000fe1fda8 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365
1 lock held by syz-executor.2/718:
 #0: ffff88807bb31c68 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962
4 locks held by syz-executor.2/726:
1 lock held by syz-executor.2/1902:
 #0: ffff88807d0e4868 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962
1 lock held by syz-executor.2/1912:

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.3.0-rc2-next-20230316-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xe16/0x1090 kernel/hung_task.c:379
 kthread+0x33e/0x440 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6597 Comm: kworker/u4:10 Not tainted 6.3.0-rc2-next-20230316-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Workqueue: bat_events batadv_nc_worker
RIP: 0010:mark_lock.part.0+0x6f/0x1970 kernel/locking/lockdep.c:4610
Code: c7 44 24 48 00 47 64 81 c7 00 f1 f1 f1 f1 c7 40 04 f1 f1 04 f2 c7 40 08 00 f2 f2 f2 c7 40 0c 00 f2 f2 f2 c7 40 14 00 00 00 f3 <c7> 40 18 f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 30 01
RSP: 0018:ffffc900060f7a38 EFLAGS: 00000806
RAX: fffff52000c1ef4e RBX: 1ffff92000c1ef4e RCX: 1ffffffff22a7bc6
RDX: dffffc0000000000 RSI: ffff88802821c4e0 RDI: ffff88802821ba80
RBP: 0000000000000006 R08: 0000000000000000 R09: ffffffff914ebd1f
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88802821c4e0
R13: 0000000000000006 R14: ffff88802821c4b8 R15: ffffffff89cf9970
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c017f71000 CR3: 000000000c571000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mark_lock kernel/locking/lockdep.c:4615 [inline]
 mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4247
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4273 [inline]
 lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4332 [inline]
 lockdep_hardirqs_on_prepare+0x28f/0x410 kernel/locking/lockdep.c:4284
 trace_hardirqs_on+0x36/0x40 kernel/trace/trace_preemptirq.c:61
 __local_bh_enable_ip+0xa4/0x130 kernel/softirq.c:401
 spin_unlock_bh include/linux/spinlock.h:395 [inline]
 batadv_nc_purge_paths+0x1cc/0x3c0 net/batman-adv/network-coding.c:471
 batadv_nc_worker+0x931/0xfe0 net/batman-adv/network-coding.c:722
 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390
 worker_thread+0x669/0x1090 kernel/workqueue.c:2537
 kthread+0x33e/0x440 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>