INFO: task kworker/u8:11:3058 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:11 state:D stack:21016 pid:3058 tgid:3058 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2c5/0x5d0 kernel/sched/completion.c:153
__debugfs_file_removed fs/debugfs/inode.c:754 [inline]
remove_one+0x2df/0x3b0 fs/debugfs/inode.c:761
__simple_recursive_removal+0x215/0x520 fs/libfs.c:623
debugfs_remove+0x5b/0x70 fs/debugfs/inode.c:784
nsim_dev_health_exit+0x41/0xc0 drivers/net/netdevsim/health.c:227
nsim_dev_reload_destroy+0x2bf/0x490 drivers/net/netdevsim/dev.c:1713
nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:963
devlink_reload+0x1ed/0x7f0 net/devlink/dev.c:462
devlink_pernet_pre_exit+0x1d9/0x560 net/devlink/core.c:584
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x17d/0x8f0 net/core/net_namespace.c:235
cleanup_net+0x572/0x810 net/core/net_namespace.c:706
process_one_work kernel/workqueue.c:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.7.580:8162 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.580 state:D stack:25456 pid:8162 tgid:8160 ppid:6992 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
devlink_health_report+0x305/0xb20 net/devlink/health.c:680
nsim_dev_health_break_write+0x194/0x240 drivers/net/netdevsim/health.c:162
full_proxy_write+0x127/0x1f0 fs/debugfs/file.c:389
vfs_write+0x296/0xba0 fs/read_write.c:685
ksys_write+0x150/0x270 fs/read_write.c:1036
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4be399f559
RSP: 002b:00007f4be4783028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4be3c25fa0 RCX: 00007f4be399f559
RDX: 0000000000000001 RSI: 0000200000000240 RDI: 0000000000000003
RBP: 00007f4be3a36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4be3c26038 R14: 00007f4be3c25fa0 R15: 00007fff51ac6688
Showing all locks held in the system:
locks held by khungtaskd/35: 1, last CPU#0:
#0: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:11/3058: 6, on CPU#0:
#0: ffff88801d28e148 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801d28e148 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801d28e148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88801d28e148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc9000599fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000599fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000599fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc9000599fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffffffff91685048 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
#3: ffff8880337df128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff8880337df128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#3: ffff8880337df128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x122/0x560 net/devlink/core.c:581
#4: ffff8880337de258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:314 [inline]
#4: ffff8880337de258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#4: ffff8880337de258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x138/0x560 net/devlink/core.c:581
#5: ffff888072de9e20 (&sb->s_type->i_mutex_key#8/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1071 [inline]
#5: ffff888072de9e20 (&sb->s_type->i_mutex_key#8/2){+.+.}-{4:4}, at: __simple_recursive_removal+0x19a/0x520 fs/libfs.c:619
locks held by getty/5390: 2, on CPU#1:
#0: ffff8880376bb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/6882: 4, last CPU#0:
#0: ffffffff9023a5b0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff9023a5b0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x10a/0x470 kernel/fork.c:1594
#1: ffff888030b0e540 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline]
#1: ffff888030b0e540 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x18a/0x1e10 mm/mmap.c:1716
#2: ffff88807e5b1bc0 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:556 [inline]
#2: ffff88807e5b1bc0 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x277/0x1e10 mm/mmap.c:1723
#3: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302
locks held by syz-executor/7525: 4, last CPU#0:
#0: ffffffff9023a5b0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff9023a5b0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x10a/0x470 kernel/fork.c:1594
#1: ffff888037703440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline]
#1: ffff888037703440 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x18a/0x1e10 mm/mmap.c:1716
#2: ffff88807c0ab440 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:556 [inline]
#2: ffff88807c0ab440 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x277/0x1e10 mm/mmap.c:1723
#3: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#3: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.7.580/8162: 3, on CPU#0:
#0: ffff88807e47feb0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x118/0x160 fs/file.c:1409
#1: ffff888021292478 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2762 [inline]
#1: ffff888021292478 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffff8880337de258 (&devlink->lock_key#5){+.+.}-{4:4}, at: devlink_health_report+0x305/0xb20 net/devlink/health.c:680
locks held by syz-executor/8316: 1, last CPU#0:
#0: ffff88803360e478 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:531
locks held by syz.4.914/9749: 3, last CPU#0:
#0: ffff88801dac6478 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2762 [inline]
#0: ffff88801dac6478 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#1: ffff888052470288 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1026 [inline]
#1: ffff888052470288 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3674
#2: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#2: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#2: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#2: ffffffff9015a420 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:377 [inline]
watchdog+0x1073/0x10f0 kernel/hung_task.c:598
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245