INFO: task syz.4.1826:25033 blocked for more than 143 sec[ 1420.921588][ T38] INFO: task syz.4.1826:25033 blocked for more than 143 seconds.
Tainted: G W syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1826 state:D stack:29352 pid:25033 tgid:25023 ppid:22310 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock_nested include/linux/fs.h:914 [inline]
filename_create+0x1f8/0x3c0 fs/namei.c:4139
do_mkdirat+0xa0/0x590 fs/namei.c:4391
__do_sys_mkdirat fs/namei.c:4416 [inline]
__se_sys_mkdirat fs/namei.c:4414 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4414
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fde99cbd457
RSP: 002b:00007fde97efce68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fde97efcef0 RCX: 00007fde99cbd457
RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000c0
R13: 00007fde97efceb0 R14: 0000000000000000 R15: 0000000000000000
INFO: task syz.4.1826:25034 blocked for more than 143 seconds.
Tainted: G W syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1826 state:D stack:29144 pid:25034 tgid:25023 ppid:22310 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:884 [inline]
lookup_slow+0x46/0x70 fs/namei.c:1824
walk_component+0x2d2/0x400 fs/namei.c:2129
lookup_last fs/namei.c:2630 [inline]
path_lookupat+0x163/0x430 fs/namei.c:2654
filename_lookup+0x212/0x570 fs/namei.c:2683
user_path_at+0x3a/0x60 fs/namei.c:3127
do_mount fs/namespace.c:4133 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x2d3/0x410 fs/namespace.c:4324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fde99cbebe9
RSP: 002b:00007fde97edc038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fde99ee6180 RCX: 00007fde99cbebe9
RDX: 0000200000000b80 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007fde99d41e19 R08: 0000200000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fde99ee6218 R14: 00007fde99ee6180 R15: 00007ffcd50b7de8
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G W syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 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]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Tainted: G W syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 3e ca 7f 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 3f fd de fc 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:ffffc90000167890 EFLAGS: 00000202
RAX: 1ffffffff3274800 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff993a4810 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff853e9160 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff993a4580 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881268c5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffbbeffd18 CR3: 00000000b0f2a000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1984
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3288 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3311 [inline]
serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3396
console_emit_next_record kernel/printk/printk.c:3118 [inline]
console_flush_all+0x698/0xcd0 kernel/printk/printk.c:3226
__console_flush_and_unlock+0xa4/0x240 kernel/printk/printk.c:3285
legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3638
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245