INFO: task kworker/u8:0:12 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc4-syzkaller-00108-g17bbde2e1716 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D stack:19784 pid:12    tgid:12    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/u8:0/12:
 #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: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8f4f0d50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
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
2 locks held by kworker/u8:5/978:
5 locks held by kworker/u8:7/1167:
2 locks held by getty/5584:
 #0: ffff8880309360a0 (&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
1 lock held by udevd/5836:
 #0: ffff888148c887a0 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline]
 #0: ffff888148c887a0 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:832
3 locks held by udevd/6476:
4 locks held by kworker/u8:10/18135:
1 lock held by syz-executor/20425:
 #0: ffff88805630c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff88805630c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff88805630c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
2 locks held by syz-executor/20432:
 #0: ffff8880932060e0 (&type->s_umount_key#70){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff8880932060e0 (&type->s_umount_key#70){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff8880932060e0 (&type->s_umount_key#70){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e144800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786
1 lock held by syz.6.1805/22418:
2 locks held by syz.4.1804/22422:
1 lock held by syz.5.1808/22428:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00108-g17bbde2e1716 #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: 6473 Comm: udevd Not tainted 6.16.0-rc4-syzkaller-00108-g17bbde2e1716 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_preemption_disabled+0x0/0x120 lib/smp_processor_id.c:13
Code: c7 20 b9 e1 8b 48 c7 c6 60 b9 e1 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 53 48 83 ec 10 65 48 8b 05 1e be 39 07 48 89 44 24
RSP: 0018:ffffc900056deaa8 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 0000000000000202 RCX: 1a6868c44fc9bc00
RDX: ffffc900056dec01 RSI: ffffffff8d98205e RDI: ffffffff8be1b980
RBP: dffffc0000000000 R08: ffffc900056decd0 R09: 0000000000000000
R10: ffffc900056dec98 R11: fffff52000adbd95 R12: ffffc900056dece0
R13: ffffffff81728af5 R14: ffffffff8e13ee20 R15: ffff888025ec9e00
FS:  00007f8e4bfdf880(0000) GS:ffff888125c84000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e4bfa7000 CR3: 0000000076b7e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:468 [inline]
 lock_release+0xbc/0x3e0 kernel/locking/lockdep.c:5891
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
 __call_rcu_common kernel/rcu/tree.c:3094 [inline]
 call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3214
 mas_wr_node_store lib/maple_tree.c:3887 [inline]
 mas_wr_store_entry+0x1f1b/0x25b0 lib/maple_tree.c:4098
 mas_store_prealloc+0xb00/0xf60 lib/maple_tree.c:5506
 commit_merge+0x5fc/0x700 mm/vma.c:762
 vma_merge_existing_range mm/vma.c:970 [inline]
 vma_modify+0xfc1/0x1970 mm/vma.c:1603
 vma_modify_flags+0x1e8/0x230 mm/vma.c:1644
 mprotect_fixup+0x400/0x9b0 mm/mprotect.c:658
 do_mprotect_pkey+0x8cd/0xce0 mm/mprotect.c:832
 __do_sys_mprotect mm/mprotect.c:853 [inline]
 __se_sys_mprotect mm/mprotect.c:850 [inline]
 __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:850
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8e4b91dfe7
Code: ef e8 3d fa ff ff 84 c0 75 b9 31 db 48 83 c4 08 48 89 d8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 0f 1f 44 00 00 b8 0a 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 2d 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc30e20d58 EFLAGS: 00000246 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 0000000000000200 RCX: 00007f8e4b91dfe7
RDX: 0000000000000001 RSI: 0000000000000200 RDI: 00007f8e4bfa7000
RBP: 0000558a8ad19270 R08: 0000000000000000 R09: 0000000000000200
R10: 0000558a8ad192d0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000f89200 R14: 0000558a8ad258b8 R15: 00007f8e4c10639c
 </TASK>