INFO: task syz.5.376:8461 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.376 stat[ 453.042987][ T37] task:syz.5.376 state:D stack:28648 pid:8461 tgid:8432 ppid:6533 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]
lock_rename fs/namei.c:3762 [inline]
__start_renaming+0x148/0x410 fs/namei.c:3858
filename_renameat2+0x38c/0x9c0 fs/namei.c:6125
__do_sys_renameat2 fs/namei.c:6179 [inline]
__se_sys_renameat2+0x5a/0x2c0 fs/namei.c:6174
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: 0033:0x7f084ffac819
RSP: 002b:00007f084e1dd028 EFLAGS: 00000246 ORIG_RAX: 000000000000013c
RAX: ffffffffffffffda RBX: 00007f0850226090 RCX: 00007f084ffac819
RDX: ffffffffffffff9c RSI: 00002000000007c0 RDI: ffffffffffffff9c
RBP: 00007f0850042c91 R08: 0000000000000002 R09: 0000000000000000
R10: 0000200000000680 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0850226128 R14: 00007f0850226090 R15: 00007fff065de668
INFO: task syz.5.376:8463 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.376 state:D stack:28096 pid:8463 tgid:8432 ppid:6533 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:2929 [inline]
start_dirop fs/namei.c:2940 [inline]
filename_create+0x200/0x370 fs/namei.c:4928
filename_symlinkat+0xf7/0x420 fs/namei.c:5640
__do_sys_symlinkat fs/namei.c:5666 [inline]
__se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5661
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: 0033:0x7f084ffac819
RSP: 002b:00007f084e1bc028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f0850226180 RCX: 00007f084ffac819
RDX: 0000200000000000 RSI: ffffffffffffff9c RDI: 0000200000002040
RBP: 00007f0850042c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0850226218 R14: 00007f0850226180 R15: 00007fff065de668
INFO: task syz.5.376:8464 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.376 state:D stack:29024 pid:8464 tgid:8432 ppid:6533 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:2929 [inline]
start_dirop fs/namei.c:2940 [inline]
filename_create+0x200/0x370 fs/namei.c:4928
filename_mkdirat+0xd2/0x520 fs/namei.c:5265
__do_sys_mkdirat fs/namei.c:5293 [inline]
__se_sys_mkdirat+0x35/0x150 fs/namei.c:5290
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: 0033:0x7f084ffab687
RSP: 002b:00007f084dd98e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f084dd98ee0 RCX: 00007f084ffab687
RDX: 00000000000001ff RSI: 0000200000000100 RDI: 00000000ffffff9c
RBP: 0000200000000000 R08: 00002000000002c0 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000200000000100
R13: 00007f084dd98ea0 R14: 0000000000000000 R15: 0000200000000140
Showing all locks held in the system:
7 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/37:
#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
4 locks held by kworker/u8:2/42:
#0: ffff88801d68d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801d68d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90000b47c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90000b47c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff8880256120d0 (&type->s_umount_key#81){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff88804ce71568 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
1 lock held by udevd/5165:
#0: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x9e/0x5e0 fs/kernfs/dir.c:1185
2 locks held by getty/5554:
#0: ffff8880373100a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211
4 locks held by syz.5.376/8433:
2 locks held by syz.5.376/8461:
#0: ffff888025612480 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3762 [inline]
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3858
2 locks held by syz.5.376/8463:
#0: ffff888025612480 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline]
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline]
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4928
2 locks held by syz.5.376/8464:
#0: ffff888025612480 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline]
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline]
#1: ffff88804ce71938 (&type->i_mutex_dir_key#9/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4928
2 locks held by syz-executor/9159:
#0: ffff888025e334c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1af/0x660 block/bdev.c:1144
#1: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x130 fs/kernfs/dir.c:1717
4 locks held by syz.1.606/9907:
3 locks held by dhcpcd-run-hook/9925:
2 locks held by syz.7.612/9927:
3 locks held by udevadm/9957:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 5e fe 93 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 1f 22 fa fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 5a 6a f7 05 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001679d0 EFLAGS: 00000202
RAX: 1ffffffff332bb00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff9995dd10 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff853087c0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9995da80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126432000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a6d274d048 CR3: 0000000053d08000 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:1970
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline]
serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3163 [inline]
console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3269
legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712
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