INFO: task kworker/u8:18:2776 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:18 state:D stack:22312 pid:2776 tgid:2776 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 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+0x497/0x990 net/core/net_namespace.c:251
cleanup_net+0x4c5/0x800 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+0x70e/0x8a0 kernel/kthread.c:463
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/31:
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5628:
#0:
ffff888033dae0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}
, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/1:9/21465:
#0: ffff88802168ad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88802168ad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000c327bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000c327bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff8881457e2198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff8881457e2198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff888023b5c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#3: ffff888023b5c198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff88802f89f160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff88802f89f160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
3 locks held by kworker/u8:18/2776:
#0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000b6b7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000b6b7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f52b930 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658
1 lock held by syz.3.9730/6617:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x70e/0x8a0 kernel/kthread.c:463
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6617 Comm: syz.3.9730 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline]
RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline]
RIP: 0010:native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:212
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc f3 0f 1e fa 89 f6 31 d2 e9 92 9b 8e 03 66
RSP: 0018:ffffc90000a08db0 EFLAGS: 00000046
RAX: 0000000000001dd3 RBX: ffff8880b8723900 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 0000000000001dd3 RDI: 0000000000000838
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81ae021e
R10: 0000000000000003 R11: ffffffff81703490 R12: 00000000100078cb
R13: dffffc0000000000 R14: 0000000000001dd3 R15: 0000000000000020
FS: 00007f1f8f0ab6c0(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555ae795c8 CR3: 0000000024ab4000 CR4: 00000000003526f0
Call Trace:
apic_write arch/x86/include/asm/apic.h:405 [inline]
lapic_next_event+0x11/0x20 arch/x86/kernel/apic/apic.c:416
clockevents_program_event+0x1cf/0x360 kernel/time/clockevents.c:334
hrtimer_update_softirq_timer kernel/time/hrtimer.c:1214 [inline]
hrtimer_run_softirq+0x23f/0x2b0 kernel/time/hrtimer.c:1845
handle_softirqs+0x283/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449
Code: 85 32 01 00 00 e8 11 87 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 00 87 1f 00 eb 06 e8 f9 86 1f 00 fb 48 c7 c7 80 e1 12 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 b9 35
RSP: 0018:ffffc90011d7ec00 EFLAGS: 00000293
RAX: ffffffff81a02487 RBX: ffffffff81a02344 RCX: ffff8880299eda00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e12e180
RBP: ffffc90011d7ed10 R08: ffffffff8fa38937 R09: 1ffffffff1f47126
R10: dffffc0000000000 R11: fffffbfff1f47127 R12: dffffc0000000000
R13: 1ffff920023afd84 R14: 0000000000000200 R15: 0000000000000053
_printk+0xcf/0x120 kernel/printk/printk.c:2475
hugetlb_show_meminfo_node+0x179/0x320 mm/hugetlb.c:5260
show_free_areas mm/show_mem.c:387 [inline]
__show_mem+0x1f48/0x2190 mm/show_mem.c:401
warn_alloc_show_mem mm/page_alloc.c:3908 [inline]
warn_alloc+0x2dd/0x310 mm/page_alloc.c:3933
__vmalloc_area_node mm/vmalloc.c:3702 [inline]
__vmalloc_node_range_noprof+0x67e/0x12f0 mm/vmalloc.c:3893
vmalloc_user_noprof+0xad/0xf0 mm/vmalloc.c:4046
vb2_vmalloc_alloc+0xef/0x340 drivers/media/common/videobuf2/videobuf2-vmalloc.c:47
__vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:242 [inline]
__vb2_queue_alloc+0x9bf/0x15a0 drivers/media/common/videobuf2/videobuf2-core.c:523
vb2_core_reqbufs+0xc31/0x1420 drivers/media/common/videobuf2/videobuf2-core.c:964
__vb2_init_fileio+0x318/0xff0 drivers/media/common/videobuf2/videobuf2-core.c:2895
vb2_core_poll+0x4c1/0x840 drivers/media/common/videobuf2/videobuf2-core.c:2729
vb2_poll drivers/media/common/videobuf2/videobuf2-v4l2.c:979 [inline]
vb2_fop_poll+0x168/0x380 drivers/media/common/videobuf2/videobuf2-v4l2.c:1244
v4l2_poll+0x144/0x2c0 drivers/media/v4l2-core/v4l2-dev.c:350
vfs_poll include/linux/poll.h:82 [inline]
do_pollfd fs/select.c:870 [inline]
do_poll fs/select.c:913 [inline]
do_sys_poll+0x8c6/0x1070 fs/select.c:1009
__do_sys_ppoll fs/select.c:1115 [inline]
__se_sys_ppoll+0x1ff/0x260 fs/select.c:1095
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: 0033:0x7f1f8e18ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1f8f0ab038 EFLAGS: 00000246 ORIG_RAX: 000000000000010f
RAX: ffffffffffffffda RBX: 00007f1f8e3b5fa0 RCX: 00007f1f8e18ebe9
RDX: 0000000000000000 RSI: 20000000000000dc RDI: 00002000000000c0
RBP: 00007f1f8e211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1f8e3b6038 R14: 00007f1f8e3b5fa0 R15: 00007f1f8e4dfa28