INFO: task syz.2.207:7741 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.207 state:D stack:24728 pid:7741 tgid:7740 ppid:7299 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
io_schedule+0x81/0xe0 kernel/sched/core.c:7789
folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
release_metapage+0x103/0xab0 fs/jfs/jfs_metapage.c:870
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0x9a3/0xde0 fs/jfs/jfs_metapage.c:753
dtSplitPage+0x7f8/0x3b20 fs/jfs/jfs_dtree.c:1471
dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
dtInsert+0x109b/0x5f40 fs/jfs/jfs_dtree.c:871
jfs_mkdir+0x6ec/0xa70 fs/jfs/namei.c:270
vfs_mkdir+0x52d/0x5d0 fs/namei.c:5130
do_mkdirat+0x27a/0x4b0 fs/namei.c:5164
__do_sys_mkdir fs/namei.c:5191 [inline]
__se_sys_mkdir fs/namei.c:5189 [inline]
__x64_sys_mkdir+0x6c/0x80 fs/namei.c:5189
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: 0033:0x7fd44d6ff749
RSP: 002b:00007fd44b966038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007fd44d955fa0 RCX: 00007fd44d6ff749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007fd44d783f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd44d956038 R14: 00007fd44d955fa0 R15: 00007ffecaaeb6a8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae8c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:17/4040:
#0: ffff88814047c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814047c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000e07fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000e07fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88802344c0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff88805c629f28 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
2 locks held by getty/5558:
#0: ffff8880341c50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:4/5812:
4 locks held by syz.2.207/7741:
#0: ffff88802344c480 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88805c62a2f8 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff88805c62a2f8 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
#1: ffff88805c62a2f8 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
#1: ffff88805c62a2f8 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4879
#2: ffff88805c629f28 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_mkdir+0x1fb/0xa70 fs/jfs/namei.c:233
#3: ffff88805c61e368 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_mkdir+0x216/0xa70 fs/jfs/namei.c:234
3 locks held by udevd/7847:
6 locks held by kworker/1:8/7853:
1 lock held by udevd/7878:
1 lock held by udevd/7981:
2 locks held by syz.6.266/8642:
#0: ffff88802344c0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88802344c0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
#1: ffff888023f468c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline]
#1: ffff888023f468c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1af/0xb80 fs/fs-writeback.c:2892
1 lock held by syz.7.371/9489:
1 lock held by syz.9.370/9495:
1 lock held by syz.4.372/9509:
2 locks held by syz.5.374/9510:
=============================================
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: 7853 Comm: kworker/1:8 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:rtlock_slowlock_locked+0xcb/0x4010 kernel/locking/rtmutex.c:1839
Code: 00 83 3d 87 2b 07 04 00 74 17 49 8d 7c 24 18 be ff ff ff ff e8 46 7b fd ff 85 c0 0f 84 4d 05 00 00 65 4c 8b 34 25 08 10 b3 91 <4c> 89 e7 4c 89 f6 31 d2 e8 48 3f 00 00 85 c0 0f 85 2a 34 00 00 4c
RSP: 0018:ffffc90003f87500 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 1ffff920007f0ec8 RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8cfde90d RDI: ffffffff8b3f5760
RBP: ffffc90003f87750 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520007f0ed8 R12: ffff8880615bc698
R13: 0000000000000246 R14: ffff8880108bbc80 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888126def000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fefe94ab000 CR3: 0000000034380000 CR4: 00000000003526f0
Call Trace:
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x158/0x3e0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
ref_tracker_free+0x111/0x7c0 lib/ref_tracker.c:311
netdev_tracker_free include/linux/netdevice.h:4420 [inline]
netdev_put include/linux/netdevice.h:4437 [inline]
neigh_destroy+0x357/0x5c0 net/core/neighbour.c:941
neigh_periodic_work+0xb74/0xe90 net/core/neighbour.c:1030
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