INFO: task kworker/u8:9:3507 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9    state:D stack:21160 pid:3507  tgid:3507  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 afs_cell_purge+0x3d9/0x540 fs/afs/cell.c:893
 afs_net_exit+0x50/0x100 fs/afs/main.c:147
 ops_exit_list net/core/net_namespace.c:200 [inline]
 ops_undo_list+0x49a/0x990 net/core/net_namespace.c:253
 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:686
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
 #0: ffff88814c3bc948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88814c3bc948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc90000127bc0 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000127bc0 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffff8880b8639e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/u8:3/49:
3 locks held by kworker/u8:9/3507:
 #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc9000cf9fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000cf9fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8f4f0890 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
2 locks held by getty/5578:
 #0: ffff8880316fe0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/21624:
 #0: ffffffff8e87d988 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline]
 #0: ffffffff8e87d988 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1758
 #1: ffffffff8e144800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786
3 locks held by syz-executor/22915:
 #0: ffffffff8ec91b80 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ec91b80 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8ec91b80 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f4fd488 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f4fd488 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f4fd488 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054
 #2: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #2: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
2 locks held by syz.9.1649/23013:
 #0: ffff888081eea428 (sb_writers#35){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff888059afb248 (&type->i_mutex_dir_key#24){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:874 [inline]
 #1: ffff888059afb248 (&type->i_mutex_dir_key#24){+.+.}-{4:4}, at: chown_common+0x313/0x5c0 fs/open.c:778
2 locks held by syz.9.1649/23023:
4 locks held by sed/23041:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 2904 Comm: kworker/u8:7 Not tainted 6.16.0-rc4-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:trace_hardirqs_on+0x13/0x40 kernel/trace/trace_preemptirq.c:73
Code: e9 77 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 65 f0 d2 10 85 c0 74 14 48 8b 3c 24 <e8> c8 fe ff ff 65 c7 05 4d f0 d2 10 00 00 00 00 e8 a8 2f d6 ff 48
RSP: 0018:ffffc9000c40f8d8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000201 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8b89a4a0 RDI: ffffffff818590ed
RBP: ffffc9000c40f978 R08: ffffffff8f9fdaf7 R09: 1ffffffff1f3fb5e
R10: dffffc0000000000 R11: fffffbfff1f3fb5f R12: ffffffff8b2e14f8
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92001881f1c
FS:  0000000000000000(0000) GS:ffff888125c84000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f101a47e368 CR3: 000000007646a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __local_bh_enable_ip+0x12d/0x1c0 kernel/softirq.c:412
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_nc_purge_paths+0x318/0x3b0 net/batman-adv/network-coding.c:471
 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>