INFO: task kworker/u8:7:3492 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7 state:D stack:20264 pid:3492 tgid:3492 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
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+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 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:
2 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/38:
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:7/3492:
#0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000d5bfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000d5bfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecc5400 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658
2 locks held by getty/5595:
#0: ffff88823bf5c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222
2 locks held by kworker/0:3/5839:
2 locks held by udevd/5892:
1 lock held by udevd/5958:
2 locks held by kworker/u8:11/6032:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90005c17bc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90005c17bc0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
1 lock held by syz-executor/9293:
2 locks held by syz-executor/9574:
1 lock held by syz.7.678/10606:
2 locks held by syz.1.681/10622:
7 locks held by syz.6.682/10625:
1 lock held by syz.6.682/10631:
2 locks held by dhcpcd-run-hook/10629:
=============================================
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 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+0x711/0x8a0 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: 10625 Comm: syz.6.682 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__bfs kernel/locking/lockdep.c:1752 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline]
RIP: 0010:validate_chain+0xe32/0x2140 kernel/locking/lockdep.c:3908
Code: 49 8b 45 30 48 85 c0 74 26 48 8b 40 10 48 83 c0 30 49 8b 4d 00 48 89 8c 24 d0 00 00 00 48 39 c1 74 0d 4c 8b ac 24 d0 00 00 00 <4d> 85 ed 75 42 44 8b 3d 52 50 62 13 44 3b 3d 4f 50 62 13 0f 84 d5
RSP: 0018:ffffc9000416ef10 EFLAGS: 00000006
RAX: ffffffff92a6b208 RBX: 00000000000003cd RCX: ffffffff959da058
RDX: 0000000000000008 RSI: 00000000000003cd RDI: ffff888036ce5940
RBP: ffffffff92a6ab00 R08: ffffc9000416eed8 R09: 0000000000000020
R10: dffffc0000000000 R11: ffffffff819c6400 R12: ffffffff95a16118
R13: ffffffff959da058 R14: ffff888036ce6578 R15: 0000000000000633
FS: 00007f8f7922e6c0(0000) GS:ffff8881269c2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557822f608 CR3: 000000006fcee000 CR4: 00000000003526f0
Call Trace:
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
mm_set_cpus_allowed include/linux/mm_types.h:1422 [inline]
__do_set_cpus_allowed+0x367/0x7a0 kernel/sched/core.c:2768
__set_cpus_allowed_ptr_locked+0x362/0x1860 kernel/sched/core.c:3158
__set_cpus_allowed_ptr kernel/sched/core.c:3192 [inline]
migrate_enable+0x22d/0x3c0 kernel/sched/core.c:2433
__slab_alloc mm/slub.c:3983 [inline]
__slab_alloc_node mm/slub.c:4056 [inline]
slab_alloc_node mm/slub.c:4217 [inline]
__do_kmalloc_node mm/slub.c:4364 [inline]
__kmalloc_noprof+0x14d/0x430 mm/slub.c:4377
kmalloc_noprof include/linux/slab.h:909 [inline]
qtree_write_dquot+0xfa/0x5c0 fs/quota/quota_tree.c:444
v2_write_dquot+0x184/0x260 fs/quota/quota_v2.c:372
dquot_commit+0x375/0x450 fs/quota/dquot.c:512
ext4_write_dquot+0x20a/0x380 fs/ext4/super.c:6913
mark_dquot_dirty fs/quota/dquot.c:370 [inline]
mark_all_dquot_dirty+0xfe/0x460 fs/quota/dquot.c:410
__dquot_free_space+0x80b/0xc00 fs/quota/dquot.c:1928
dquot_free_space_nodirty include/linux/quotaops.h:374 [inline]
dquot_free_space include/linux/quotaops.h:379 [inline]
dquot_free_block include/linux/quotaops.h:390 [inline]
ext4_mb_clear_bb fs/ext4/mballoc.c:6640 [inline]
ext4_free_blocks+0x1333/0x1bf0 fs/ext4/mballoc.c:6760
ext4_xattr_delete_inode+0xa8c/0xc10 fs/ext4/xattr.c:2984
ext4_evict_inode+0xac9/0xee0 fs/ext4/inode.c:271
evict+0x504/0x9c0 fs/inode.c:810
do_unlinkat+0x39f/0x570 fs/namei.c:4657
__do_sys_unlink fs/namei.c:4696 [inline]
__se_sys_unlink fs/namei.c:4694 [inline]
__x64_sys_unlink+0x47/0x50 fs/namei.c:4694
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: 0033:0x7f8f7afcebe9
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:00007f8f7922e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007f8f7b205fa0 RCX: 00007f8f7afcebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007f8f7b051e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8f7b206038 R14: 00007f8f7b205fa0 R15: 00007ffd2e130098