INFO: task syz.5.737:11560 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.737 state:D stack:26688 pid:11560 tgid:11552 ppid:10502 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
inode_lock_nested include/linux/fs.h:1073 [inline]
__start_dirop fs/namei.c:2923 [inline]
start_dirop fs/namei.c:2934 [inline]
filename_create+0x200/0x370 fs/namei.c:4922
filename_mkdirat+0xd2/0x520 fs/namei.c:5259
__do_sys_mkdirat fs/namei.c:5287 [inline]
__se_sys_mkdirat+0x35/0x150 fs/namei.c:5284
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7eff7dc6b607
RSP: 002b:00007eff7be9ce58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007eff7be9cee0 RCX: 00007eff7dc6b607
RDX: 00000000000001ff RSI: 0000200000000180 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000200000002980 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000180
R13: 00007eff7be9cea0 R14: 0000000000000000 R15: 0000000000000000
Showing all locks held in the system:
4 locks held by kworker/u8:1/13:
#0: ffff88801aac4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801aac4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff888035de80d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff888062d0cfe8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
1 lock held by khungtaskd/38:
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by udevd/5162:
#0: ffff88803a008208 (&ep->lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline]
#0: ffff88803a008208 (&ep->lock){+.+.}-{3:3}, at: ep_poll fs/eventpoll.c:2040 [inline]
#0: ffff88803a008208 (&ep->lock){+.+.}-{3:3}, at: do_epoll_wait+0x851/0xbd0 fs/eventpoll.c:2462
2 locks held by getty/5550:
#0: ffff8880379e50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
5 locks held by syz.5.737/11553:
2 locks held by syz.5.737/11560:
#0: ffff888035de8480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff888062d0d3b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff888062d0d3b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff888062d0d3b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff888062d0d3b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922
2 locks held by udevd/12143:
1 lock held by udevd/12144:
7 locks held by udevd/12537:
1 lock held by syz.8.874/12856:
2 locks held by udevadm/12868:
3 locks held by syz.6.878/12885:
2 locks held by syz.4.877/12884:
3 locks held by udevadm/12888:
2 locks held by rm/12903:
=============================================
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 02/12/2026
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:161 [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+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
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: 3 Comm: pool_workqueue_ Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:remove_class_from_lock_chain kernel/locking/lockdep.c:6197 [inline]
RIP: 0010:remove_class_from_lock_chains kernel/locking/lockdep.c:6236 [inline]
RIP: 0010:zap_class+0xcf/0x340 kernel/locking/lockdep.c:6281
Code: 49 81 fc 00 00 08 00 0f 84 a4 01 00 00 4e 8b 2c e5 20 64 12 93 4d 85 ed 0f 94 c0 49 83 c5 f8 0f 94 c1 08 c1 75 d7 45 8b 75 00 <41> f6 c6 fc 0f 84 e1 00 00 00 41 c1 ee 08 4a 8d 1c 75 f0 63 57 92
RSP: 0018:ffffc90000087c50 EFLAGS: 00000046
RAX: 0000000000056300 RBX: ffffffff92622b7e RCX: 0000000000056300
RDX: ffffffff93546448 RSI: ffffffff93546448 RDI: ffffffff9303a328
RBP: ffffffff93566890 R08: ffffffff81add428 R09: ffffffff8ddcb9c0
R10: dffffc0000000000 R11: fffffbfff1ed4c77 R12: 000000000003288d
R13: ffffffff938e82f0 R14: 000000000a517210 R15: 0000000000000fad
FS: 0000000000000000(0000) GS:ffff888126436000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe241b4afe8 CR3: 0000000038d90000 CR4: 00000000003526f0
Call Trace:
__lockdep_free_key_range kernel/locking/lockdep.c:6407 [inline]
lockdep_unregister_key+0x1c3/0x350 kernel/locking/lockdep.c:6609
wq_unregister_lockdep kernel/workqueue.c:4903 [inline]
pwq_release_workfn+0x6e7/0x880 kernel/workqueue.c:5199
kthread_worker_fn+0x509/0xb70 kernel/kthread.c:1025
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245