INFO: task kworker/u8:16:4350 blocked for more than 143 seconds.
Tainted: G W 6.16.0-syzkaller-01056-gae388edd4a8f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:16 state:D stack:22136 pid:4350 tgid:4350 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x165b/0x4c50 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
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:200 [inline]
ops_undo_list+0x49a/0x990 net/core/net_namespace.c:253
cleanup_net+0x522/0x850 net/core/net_namespace.c:686
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d9aa300 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9aa300 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d9aa300 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
9 locks held by kworker/0:2/1230:
5 locks held by kworker/u8:9/1279:
3 locks held by kworker/u8:10/1282:
3 locks held by kworker/u8:16/4350:
#0: ffff88801a6f3938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a6f3938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000f0bfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000f0bfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8eca8480 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x850 net/core/net_namespace.c:662
2 locks held by getty/5580:
#0: ffff88823be468a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222
5 locks held by kworker/u8:1/7396:
2 locks held by syz.2.279/8179:
3 locks held by syz.3.280/8195:
1 lock held by udevadm/8198:
2 locks held by syz.4.281/8201:
1 lock held by syz.0.278/8205:
1 lock held by rm/8203:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G W 6.16.0-syzkaller-01056-gae388edd4a8f #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
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+0xe9e/0xee0 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8195 Comm: syz.3.280 Tainted: G W 6.16.0-syzkaller-01056-gae388edd4a8f #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:preempt_latency_start kernel/sched/core.c:5855 [inline]
RIP: 0010:preempt_count_add+0xba/0x1a0 kernel/sched/core.c:5878
Code: 00 85 c0 74 09 31 db 31 ff e8 22 c5 0c 00 65 4c 8b 34 25 08 60 f2 91 49 81 c6 e8 14 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 bc 2b 8c 00 49 89 1e 5b 41 5e 41 5f c3 cc cc cc
RSP: 0018:ffffc90005cd7730 EFLAGS: 00000246
RAX: 1ffff110064fba0d RBX: ffffffff821f1b5d RCX: ffffffff98fd9300
RDX: 0000000000000001 RSI: 0000000000000013 RDI: ffffffff821f1b5d
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff821f1ed9
R10: dffffc0000000000 R11: fffffbfff1e36fff R12: ffff88801bec0c48
R13: 0000000000000010 R14: ffff8880327dd068 R15: dffffc0000000000
FS: 00007fb77491d6c0(0000) GS:ffff8881268fa000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0062539c50 CR3: 0000000051d8a000 CR4: 00000000003526f0
Call Trace:
mod_memcg_lruvec_state+0x7d/0x370 mm/memcontrol.c:745
__mod_lruvec_state mm/memcontrol.c:778 [inline]
__lruvec_stat_mod_folio+0x1a0/0x2f0 mm/memcontrol.c:798
shmem_update_stats mm/shmem.c:875 [inline]
shmem_add_to_page_cache+0x841/0xb40 mm/shmem.c:913
shmem_alloc_and_add_folio mm/shmem.c:1916 [inline]
shmem_get_folio_gfp+0x7d2/0x1a70 mm/shmem.c:2536
shmem_get_folio mm/shmem.c:2642 [inline]
shmem_write_begin+0xef/0x2a0 mm/shmem.c:3292
generic_perform_write+0x29d/0x8c0 mm/filemap.c:4141
shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3467
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x554/0xaa0 fs/read_write.c:686
ksys_write+0x14b/0x260 fs/read_write.c:738
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: 0033:0x7fb776add45f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fb77491cdf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fb776add45f
RDX: 0000000001000000 RSI: 00007fb76c4fd000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000004700
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000005
R13: 00007fb77491cef0 R14: 00007fb77491ceb0 R15: 00007fb76c4fd000