INFO: task kworker/u8:13:9200 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:13 state:D stack:23896 pid:9200 tgid:9200 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x14fb/0x52c0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
afs_cell_purge+0x40d/0x580 fs/afs/cell.c:921
afs_net_exit+0x50/0x100 fs/afs/main.c:147
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252
cleanup_net+0x56e/0x800 net/core/net_namespace.c:704
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
6 locks held by kworker/u8:1/13:
6 locks held by ktimers/0/16:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/37:
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:8/1167:
2 locks held by getty/5551:
#0: ffff8880377d00a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211
6 locks held by kworker/u8:12/9197:
3 locks held by kworker/u8:13/9200:
#0: ffff88801aed9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801aed9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc900059d7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc900059d7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffffffff8f14afc0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
2 locks held by udevd/12771:
3 locks held by kworker/u8:17/15958:
2 locks held by syz.6.1130/16136:
3 locks held by syz.8.1132/16164:
1 lock held by rm/16167:
5 locks held by syz.0.1133/16169:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
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: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4882 [inline]
RIP: 0010:__lock_acquire+0x56f/0x2cf0 kernel/locking/lockdep.c:5187
Code: 85 c0 74 1c 83 3d d4 17 ca 0d 00 75 13 48 8d 3d 07 28 cd 0d 48 c7 c6 8d e8 66 8d 67 48 0f b9 3a 90 31 c9 0f b6 81 c4 00 00 00 <84> c0 0f 84 77 ff ff ff 41 0f b6 f4 0f b6 d0 40 38 c6 0f 42 d6 80
RSP: 0018:ffffc900001574a8 EFLAGS: 00000002
RAX: 0000000000000003 RBX: ffff88801caa8b98 RCX: ffffffff92f74f70
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88801caa8cb8 R08: ffffffff8b24289c R09: ffffffff8ddcd780
R10: dffffc0000000000 R11: fffffbfff1ed44b7 R12: ffffffffffffff05
R13: ffff88801caa8cb8 R14: ffff88801caa8000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126343000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f21403ac000 CR3: 000000005f8ea000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
__rt_spin_trylock kernel/locking/spinlock_rt.c:110 [inline]
rt_spin_trylock+0x128/0x2b0 kernel/locking/spinlock_rt.c:118
alloc_from_pcs mm/slub.c:4675 [inline]
slab_alloc_node mm/slub.c:4815 [inline]
kmem_cache_alloc_node_noprof+0x304/0x6e0 mm/slub.c:4882
kmalloc_reserve net/core/skbuff.c:613 [inline]
__alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713
skb_copy+0x188/0x800 net/core/skbuff.c:2195
mac80211_hwsim_tx_frame_no_nl+0xd00/0x11f0 drivers/net/wireless/virtual/mac80211_hwsim.c:1891
mac80211_hwsim_tx_frame+0x1b5/0x200 drivers/net/wireless/virtual/mac80211_hwsim.c:2264
mac80211_hwsim_beacon_tx+0x3e8/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2365
__iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:760
ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:796
mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x55f/0xda0 kernel/time/hrtimer.c:1849
hrtimer_run_softirq+0x192/0x5d0 kernel/time/hrtimer.c:1866
handle_softirqs+0x1de/0x6f0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1138
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245