INFO: task syz.4.1220:13863 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1220 state:D stack:25496 pid:13863 tgid:13862 ppid:11647 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
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x26e/0xb10 fs/jfs/jfs_txnmgr.c:375
jfs_mknod+0x1e7/0x960 fs/jfs/namei.c:1384
vfs_mknod+0x534/0x590 fs/namei.c:4997
do_mknodat+0x3d0/0x620 fs/namei.c:-1
__do_sys_mknod fs/namei.c:5085 [inline]
__se_sys_mknod fs/namei.c:5083 [inline]
__x64_sys_mknod+0x8c/0xa0 fs/namei.c:5083
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: 0033:0x7f8dd41af749
RSP: 002b:00007f8dd240e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f8dd4405fa0 RCX: 00007f8dd41af749
RDX: 0000000000000709 RSI: 0000000000006000 RDI: 0000200000000000
RBP: 00007f8dd4233f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8dd4406038 R14: 00007f8dd4405fa0 R15: 00007ffd11835a78
Showing all locks held in the system:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/58:
3 locks held by udevd/5171:
#0: ffff88805b95ce18 (kn->active#5){.+.+}-{0:0}, at: kernfs_fop_open+0x5a/0xcb0 fs/kernfs/file.c:619
#1: ffff888140451ed8 (&kernfs_locks->open_file_mutex[count]){+.+.}-{4:4}, at: kernfs_open_file_mutex_lock fs/kernfs/file.c:56 [inline]
#1: ffff888140451ed8 (&kernfs_locks->open_file_mutex[count]){+.+.}-{4:4}, at: kernfs_get_open_node fs/kernfs/file.c:538 [inline]
#1: ffff888140451ed8 (&kernfs_locks->open_file_mutex[count]){+.+.}-{4:4}, at: kernfs_fop_open+0x6e6/0xcb0 fs/kernfs/file.c:718
#2: ffff88813ff25358 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffff88813ff25358 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node+0x44/0x3e0 mm/slub.c:3514
2 locks held by getty/5561:
#0: ffff888034afb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
2 locks held by kworker/u8:26/8071:
2 locks held by syz.4.1220/13863:
#0: ffff888020320480 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88805d1ed3b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff88805d1ed3b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline]
#1: ffff88805d1ed3b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline]
#1: ffff88805d1ed3b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4888
1 lock held by udevd/14545:
#0: ffff888148df88a8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline]
#0: ffff888148df88a8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:855
3 locks held by udevd/14729:
2 locks held by syz.8.1279/15171:
#0: ffff888147f700d0 (&type->s_umount_key#67/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
#1: ffff88805b6e9158 (btrfs-tree-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x31/0x210 fs/btrfs/locking.c:145
2 locks held by syz.6.1281/15179:
#0: ffff8880345640d0 (&type->s_umount_key#67/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
#1: ffffffff8d456a38 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5215 [inline]
#1: ffffffff8d456a38 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa07/0x1b80 kernel/workqueue.c:5768
2 locks held by syz.7.1283/15183:
1 lock held by syz.9.1282/15185:
4 locks held by syz.3.1284/15199:
3 locks held by udevadm/15204:
#0: ffff8880217473c8 (kn->active#5){.+.+}-{0:0}, at: kernfs_fop_open+0x5a/0xcb0 fs/kernfs/file.c:619
#1: ffff8881404513d8 (&kernfs_locks->open_file_mutex[count]){+.+.}-{4:4}, at: kernfs_open_file_mutex_lock fs/kernfs/file.c:56 [inline]
#1: ffff8881404513d8 (&kernfs_locks->open_file_mutex[count]){+.+.}-{4:4}, at: kernfs_get_open_node fs/kernfs/file.c:538 [inline]
#1: ffff8881404513d8 (&kernfs_locks->open_file_mutex[count]){+.+.}-{4:4}, at: kernfs_fop_open+0x6e6/0xcb0 fs/kernfs/file.c:718
#2: ffff88813ff25358 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffff88813ff25358 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node+0x44/0x3e0 mm/slub.c:3514
6 locks held by dhcpcd-run-hook/15220:
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 4e da b5 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf 13 18 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90000167950 EFLAGS: 00000202
RAX: 1ffffffff31f3700 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff98f9c010 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8509d220 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff98f9bd80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126cee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4631268eb0 CR3: 0000000086886000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3109 [inline]
console_flush_one_record+0x685/0xb80 kernel/printk/printk.c:3215
legacy_kthread_func+0x16f/0x210 kernel/printk/printk.c:3674
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