INFO: task kworker/u4:18:7588 blocked for more than 143 seconds.
      Not tainted 6.1.0-syzkaller-13031-g77856d911a8c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:18   state:D stack:19808 pid:7588  ppid:2      flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x9d1/0xe40 kernel/sched/core.c:6555
 schedule+0xcb/0x190 kernel/sched/core.c:6631
 rxrpc_destroy_all_calls+0x585/0x680 net/rxrpc/call_object.c:733
 rxrpc_exit_net+0x6a/0xc0 net/rxrpc/net_ns.c:125
 ops_exit_list net/core/net_namespace.c:169 [inline]
 cleanup_net+0x758/0xc60 net/core/net_namespace.c:606
 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d3238d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d3240d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/28:
 #0: ffffffff8d323700 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/4741:
 #0: ffff88814b4b0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6e8/0x1e50 drivers/tty/n_tty.c:2177
3 locks held by kworker/u4:18/7588:
 #0: ffff8880129cb138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
 #1: ffffc90016357d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
 #2: ffffffff8e456410 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf0/0xc60 net/core/net_namespace.c:568
3 locks held by kworker/u4:3/2224:
2 locks held by syz-executor.1/29258:

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.0-syzkaller-13031-g77856d911a8c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e3/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x19b/0x3e0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xcd5/0xd20 kernel/hung_task.c:377
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2224 Comm: kworker/u4:3 Not tainted 6.1.0-syzkaller-13031-g77856d911a8c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0x355/0x1f60 kernel/locking/lockdep.c:4991
Code: cc 77 00 4c 89 e1 48 ba 00 00 00 00 00 fc ff df 48 89 0b 48 8b 04 24 48 8d 9c e8 48 0a 00 00 48 89 d8 48 c1 e8 03 80 3c 10 00 <44> 8b 64 24 24 74 12 48 89 df e8 fc cb 77 00 48 ba 00 00 00 00 00
RSP: 0018:ffffc900036a7988 EFLAGS: 00000046
RAX: 1ffff11014e9fc4b RBX: ffff8880a74fe258 RCX: ffffffff8a859d45
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff8d323700
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff1d200ae R11: 1ffffffff1d200ad R12: ffff8880a74fe268
R13: ffffffff8d323700 R14: 0000000000000000 R15: 0000000000000021
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3f6ed84998 CR3: 000000000d08e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5668
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:325
 rcu_read_lock include/linux/rcupdate.h:764 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xc8/0x5b0 net/batman-adv/network-coding.c:719
 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>