INFO: task kworker/u8:14:3545 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:14 state:D stack:22104 pid:3545 tgid:3545 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
afs_cell_purge+0x3f1/0x540 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+0x49a/0x990 net/core/net_namespace.c:252
cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:14/3545:
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000d81fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000d81fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8e898720 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:670
2 locks held by getty/5555:
#0: ffff888034c9d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/12230:
#0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:37 [inline]
#0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: __do_wait+0xe1/0x740 kernel/exit.c:1672
1 lock held by syz-executor/12309:
#0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:37 [inline]
#0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: __do_wait+0xe1/0x740 kernel/exit.c:1672
1 lock held by syz-executor/12414:
#0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:37 [inline]
#0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: __do_wait+0xe1/0x740 kernel/exit.c:1672
3 locks held by syz-executor/12622:
#0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: write_lock_irq include/linux/rwlock_rt.h:104 [inline]
#0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: release_task+0x33b/0x16d0 kernel/exit.c:263
#1: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#1: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#1: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rt_write_lock+0x87/0x220 kernel/locking/spinlock_rt.c:244
#2: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#2: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
#2: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23d0 arch/x86/kernel/unwind_orc.c:495
3 locks held by syz-executor/12866:
6 locks held by udevd/12962:
#0: ffff888148ce2228 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline]
#0: ffff888148ce2228 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:855
#1: ffff88813ff5f670 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:410 [inline]
#1: ffff88813ff5f670 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:390 [inline]
#1: ffff88813ff5f670 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/mmap_lock.c:450
#2: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#2: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: ___pte_offset_map+0x29/0x200 mm/pgtable-generic.c:288
#3: ffff88803d4f8c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#3: ffff88803d4f8c58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:403
#4: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#4: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#4: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#4: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1c1/0x3e0 kernel/locking/spinlock_rt.c:57
#5: ffff8880b8933cd0 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#5: ffff8880b8933cd0 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x284/0xa90 mm/swap.c:-1
4 locks held by syz.5.876/12988:
2 locks held by syz.9.879/12998:
5 locks held by cmp/13000:
#0: ffff88802ee26588 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1a7/0x4a0 mm/mmap_lock.c:259
#1: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#1: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#1: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: ___pte_offset_map+0x29/0x200 mm/pgtable-generic.c:288
#2: ffff88805bfd61d8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffff88805bfd61d8 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:403
#3: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#3: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#3: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#3: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1c1/0x3e0 kernel/locking/spinlock_rt.c:57
#4: ffff8880b8933cd0 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#4: ffff8880b8933cd0 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x284/0xa90 mm/swap.c:-1
2 locks held by syz.7.880/13002:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12988 Comm: syz.5.876 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:lock_release+0x26d/0x3b0 kernel/locking/lockdep.c:5892
Code: 18 e8 17 2f 00 00 48 8b 5c 24 08 48 c7 c7 f6 ee fd 8c e8 b6 fb 34 09 b8 ff ff ff ff 65 0f c1 05 b9 a5 16 10 83 f8 01 75 2e 9c <58> a9 00 02 00 00 75 42 f7 c3 00 02 00 00 75 47 65 48 8b 05 0b 5f
RSP: 0018:ffffc90003ab75d8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000087 RCX: 0000000080000001
RDX: 0000000000000002 RSI: ffffffff8cfdeef6 RDI: ffffffff8b3f57e0
RBP: ffff88807c314860 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000756eb8 R12: 0000000000000002
R13: 0000000000000002 R14: ffff8880b893cb18 R15: ffff88807c313c80
FS: 00007fd5dce056c0(0000) GS:ffff888126def000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe376445c00 CR3: 0000000030c7e000 CR4: 00000000003526f0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
_raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:194
unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline]
rt_mutex_slowunlock+0x493/0x8a0 kernel/locking/rtmutex.c:1454
spin_unlock include/linux/spinlock_rt.h:105 [inline]
consume_stock mm/memcontrol.c:1853 [inline]
try_charge_memcg+0x5cc/0x1360 mm/memcontrol.c:2345
try_charge mm/memcontrol.c:2530 [inline]
charge_memcg+0x9f/0x180 mm/memcontrol.c:4728
__mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:4745
mem_cgroup_charge include/linux/memcontrol.h:663 [inline]
shmem_alloc_and_add_folio mm/shmem.c:1942 [inline]
shmem_get_folio_gfp+0x74e/0x1a70 mm/shmem.c:2556
shmem_get_folio mm/shmem.c:2662 [inline]
shmem_write_begin+0x166/0x320 mm/shmem.c:3315
generic_perform_write+0x29d/0x8c0 mm/filemap.c:4314
shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3490
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5d5/0xb40 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+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd5debbe1ff
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:00007fd5dce04df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fd5debbe1ff
RDX: 0000000001000000 RSI: 00007fd5d49e5000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000975e
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003
R13: 00007fd5dce04ef0 R14: 00007fd5dce04eb0 R15: 00007fd5d49e5000