INFO: task kworker/u10:0:12112 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:0 state:D stack:24936 pid:12112 tgid:12112 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__debugfs_file_removed fs/debugfs/inode.c:751 [inline]
remove_one+0x312/0x420 fs/debugfs/inode.c:758
__simple_recursive_removal+0x148/0x5c0 fs/libfs.c:624
debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:781
nsim_dev_health_exit+0x3b/0xe0 drivers/net/netdevsim/health.c:227
nsim_dev_reload_destroy+0x144/0x4a0 drivers/net/netdevsim/dev.c:1788
nsim_dev_reload_down+0x66/0xd0 drivers/net/netdevsim/dev.c:1038
devlink_reload+0x1ae/0x7a0 net/devlink/dev.c:462
devlink_pernet_pre_exit+0x247/0x370 net/devlink/core.c:558
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x187/0xab0 net/core/net_namespace.c:234
cleanup_net+0x499/0x920 net/core/net_namespace.c:702
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.3.2335:19468 blocked for more than 146 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2335 state:D stack:29032 pid:19468 tgid:19461 ppid:17061 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
devlink_health_report+0x66c/0xb20 net/devlink/health.c:680
nsim_dev_health_break_write+0x166/0x210 drivers/net/netdevsim/health.c:162
full_proxy_write+0x135/0x1a0 fs/debugfs/file.c:388
vfs_write+0x2aa/0x1070 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3fc0d9ce59
RSP: 002b:00007f3fc1c52028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3fc1016090 RCX: 00007f3fc0d9ce59
RDX: 00000000000001e1 RSI: 0000200000000080 RDI: 0000000000000006
RBP: 00007f3fc0e32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3fc1016128 R14: 00007f3fc1016090 R15: 00007ffeb04f8678
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e5360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e5360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e7e5360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
1 lock held by syz.1.592/9075:
6 locks held by kworker/u10:0/12112:
#0: ffff88801c6a6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
#1: ffffc900036dfd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
#2: ffffffff905ed8c8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
#3: ffff88807bc69128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#3: ffff88807bc69128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#3: ffff88807bc69128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x19e/0x370 net/devlink/core.c:555
#4: ffff88807bc6a258 (&devlink->lock_key#9){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
#4: ffff88807bc6a258 (&devlink->lock_key#9){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#4: ffff88807bc6a258 (&devlink->lock_key#9){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x1b4/0x370 net/devlink/core.c:555
#5: ffff888059ad22f0 (&sb->s_type->i_mutex_key#9/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
#5: ffff888059ad22f0 (&sb->s_type->i_mutex_key#9/2){+.+.}-{4:4}, at: __simple_recursive_removal+0xe0/0x5c0 fs/libfs.c:620
3 locks held by syz.3.2335/19468:
#0: ffff88807a780b70 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1261
#1: ffff8880202e0410 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#2: ffff88807bc6a258 (&devlink->lock_key#9){+.+.}-{4:4}, at: devlink_health_report+0x66c/0xb20 net/devlink/health.c:680
1 lock held by syz.7.2630/21126:
3 locks held by syz.9.2677/21377:
#0: ffffffff905ed8c8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90606620 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#1: ffffffff90606620 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248
#2: ffffffff8e7f0ea8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
4 locks held by syz.0.2679/21387:
#0: ffffffff8f93cd60 (ubi_devices_mutex){+.+.}-{4:4}, at: ctrl_cdev_ioctl+0x323/0x400 drivers/mtd/ubi/cdev.c:1112
#1: ffffffff8e67c530 (cpu_hotplug_lock){++++}-{0:0}, at: kmem_cache_destroy mm/slab_common.c:556 [inline]
#1: ffffffff8e67c530 (cpu_hotplug_lock){++++}-{0:0}, at: kmem_cache_destroy+0x4b/0x190 mm/slab_common.c:527
#2: ffffffff8e97e6a0 (slab_mutex){+.+.}-{4:4}, at: kmem_cache_destroy mm/slab_common.c:557 [inline]
#2: ffffffff8e97e6a0 (slab_mutex){+.+.}-{4:4}, at: kmem_cache_destroy+0x59/0x190 mm/slab_common.c:527
#3: ffffffff8e7f0d78 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
1 lock held by syz.0.2679/21392:
#0: ffffffff8f93cd60 (ubi_devices_mutex){+.+.}-{4:4}, at: ctrl_cdev_ioctl+0x1ea/0x400 drivers/mtd/ubi/cdev.c:1138
1 lock held by syz.0.2679/21394:
#0: ffffffff8f93cd60 (ubi_devices_mutex){+.+.}-{4:4}, at: ctrl_cdev_ioctl+0x1ea/0x400 drivers/mtd/ubi/cdev.c:1138
2 locks held by syz.0.2679/21395:
#0: ffffffff905ed8c8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90606620 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#1: ffffffff90606620 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245