INFO: task kworker/u4:9:18524 blocked for more than 144 seconds.
      Not tainted 6.1.0-syzkaller-13872-gb6bb9676f216 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:9    state:D stack:23384 pid:18524 ppid:2      flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6555
 schedule+0xde/0x1b0 kernel/sched/core.c:6631
 rxrpc_destroy_all_calls+0x1ee/0x640 net/rxrpc/call_object.c:733
 rxrpc_exit_net+0x15c/0x300 net/rxrpc/net_ns.c:125
 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169
 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:606
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 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/11:
 #0: ffffffff8c78dcb0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/12:
 #0: ffffffff8c78d9b0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/27:
 #0: ffffffff8c78e800 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x57/0x264 kernel/locking/lockdep.c:6494
1 lock held by syslogd/4403:
2 locks held by getty/4743:
 #0: ffff88814b3eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:244
 #1: ffffc900020282f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177
2 locks held by kworker/u4:15/5316:
3 locks held by kworker/u4:9/18524:
 #0: ffff888012775138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888012775138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888012775138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
 #0: ffff888012775138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
 #0: ffff888012775138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
 #0: ffff888012775138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x86d/0x1710 kernel/workqueue.c:2260
 #1: ffffc900034ffda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a1/0x1710 kernel/workqueue.c:2264
 #2: ffffffff8e0a0d10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9f/0xb10 net/core/net_namespace.c:568
3 locks held by kworker/u4:1/24670:
2 locks held by syz-executor.4/27261:
 #0: ffffffff8e0a0d10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2f8/0x6b0 net/core/net_namespace.c:479
 #1: ffffffff8c799380 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3995

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.0-syzkaller-13872-gb6bb9676f216 #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+0xd1/0x138 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x24/0x18a lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x333/0x3c0 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+0xc75/0xfc0 kernel/hung_task.c:377
 kthread+0x2e8/0x3a0 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: 55 Comm: kworker/u4:4 Not tainted 6.1.0-syzkaller-13872-gb6bb9676f216 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_region_inline mm/kasan/generic.c:170 [inline]
RIP: 0010:kasan_check_range+0x130/0x190 mm/kasan/generic.c:189
Code: 00 74 ef 49 8d 04 2c 48 85 d2 75 0b 48 89 da 48 29 c2 e9 55 ff ff ff 49 39 d2 75 17 49 0f be 02 41 83 e1 07 49 39 c1 7d 0a 5b <b8> 01 00 00 00 5d 41 5c c3 44 89 c2 e8 7f ee ff ff 5b 83 f0 01 5d
RSP: 0018:ffffc9000201fa10 EFLAGS: 00000046
RAX: fffffbfff2265974 RBX: 00000000000006e7 RCX: ffffffff8162b400
RDX: fffffbfff2265974 RSI: 0000000000000008 RDI: ffffffff9132cb98
RBP: fffffbfff2265973 R08: 0000000000000000 R09: ffffffff9132cb9f
R10: fffffbfff2265973 R11: 0000000000000000 R12: 0000000000000001
R13: ffff888018698040 R14: ffff888018698a78 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5af39821b8 CR3: 000000007e57d000 CR4: 00000000003506e0
DR0: 00000000ffaf060c DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 hlock_class kernel/locking/lockdep.c:227 [inline]
 check_wait_context kernel/locking/lockdep.c:4754 [inline]
 __lock_acquire+0x6f0/0x56d0 kernel/locking/lockdep.c:5005
 lock_acquire kernel/locking/lockdep.c:5668 [inline]
 lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633
 rcu_lock_acquire include/linux/rcupdate.h:325 [inline]
 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+0x131/0xfa0 net/batman-adv/network-coding.c:719
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>