INFO: task kworker/u8:0:202[ 1622.970214][   T39] INFO: task kworker/u8:0:20278 blocked for more than 143 seconds.
      Tainted: G        W           6.17.0-rc1-syzkaller-00165-gee94b00c1a64 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D stack:20328 pid:20278 tgid:20278 ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 afs_cell_purge+0x3d9/0x540 fs/afs/cell.c:894
 afs_net_exit+0x50/0x100 fs/afs/main.c:147
 ops_exit_list net/core/net_namespace.c:198 [inline]
 ops_undo_list+0x49a/0x990 net/core/net_namespace.c:251
 cleanup_net+0x4cb/0x800 net/core/net_namespace.c:682
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 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>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G        W           6.17.0-rc1-syzkaller-00165-gee94b00c1a64 #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x711/0x8a0 kernel/kthread.c:463
 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Tainted: G        W           6.17.0-rc1-syzkaller-00165-gee94b00c1a64 #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:_raw_spin_lock_irqsave+0xe1/0xf0 kernel/locking/spinlock.c:162
Code: 0e 36 e0 45 4b c7 04 27 00 00 00 00 65 48 8b 05 15 30 fc 06 48 3b 44 24 48 75 15 4c 89 f0 48 8d 65 e0 5b 41 5c 41 5e 41 5f 5d <c3> cc cc cc cc cc e8 84 90 fc ff 0f 1f 40 00 90 90 90 90 90 90 90
RSP: 0018:ffffc90000a3f3d8 EFLAGS: 00000046
RAX: 0000000000000a02 RBX: ffffffff99253038 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000a3f2c0
RBP: 0000000000212110 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000147e58 R12: ffff8880318ba000
R13: ffff8880318bb040 R14: 0000000000000000 R15: ffffea0000c62e00
FS:  0000000000000000(0000) GS:ffff8881269c5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbd3262ab4c CR3: 0000000097d40000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __debug_check_no_obj_freed lib/debugobjects.c:1088 [inline]
 debug_check_no_obj_freed+0x17a/0x470 lib/debugobjects.c:1129
 slab_free_hook mm/slub.c:2348 [inline]
 slab_free mm/slub.c:4680 [inline]
 kmem_cache_free+0x113/0x510 mm/slub.c:4782
 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1086
 skb_release_all net/core/skbuff.c:1151 [inline]
 __kfree_skb net/core/skbuff.c:1165 [inline]
 sk_skb_reason_drop+0x127/0x170 net/core/skbuff.c:1203
 kfree_skb_reason include/linux/skbuff.h:1275 [inline]
 kfree_skb include/linux/skbuff.h:1284 [inline]
 ip6_mc_input+0x8f4/0xaf0 net/ipv6/ip6_input.c:593
 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:318
 __netif_receive_skb_one_core net/core/dev.c:5979 [inline]
 __netif_receive_skb+0xd3/0x380 net/core/dev.c:6092
 process_backlog+0x31e/0x900 net/core/dev.c:6444
 __napi_poll+0xb3/0x540 net/core/dev.c:7494
 napi_poll net/core/dev.c:7557 [inline]
 net_rx_action+0x707/0xe00 net/core/dev.c:7684
 handle_softirqs+0x22c/0x710 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 run_ktimerd+0xcf/0x190 kernel/softirq.c:1043
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 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>