syzbot

INFO: task syz.0.1744:14720 blocked for more than 143 seconds.
      Tainted: G     U       L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1744      state:D stack:27184 pid:14720 tgid:14719 ppid:8782   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5504 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7228
 __schedule_loop kernel/sched/core.c:7307 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7322
 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:293 [inline]
 __down_common+0x371/0x8b0 kernel/locking/semaphore.c:318
 down+0x74/0xa0 kernel/locking/semaphore.c:100
 console_lock+0x5b/0xa0 kernel/printk/printk.c:2896
 class_console_lock_constructor include/linux/console.h:734 [inline]
 con_install+0x99/0x620 drivers/tty/vt/vt.c:3742
 tty_driver_install_tty drivers/tty/tty_io.c:1295 [inline]
 tty_init_dev.part.0+0x9e/0x470 drivers/tty/tty_io.c:1407
 tty_init_dev include/linux/err.h:78 [inline]
 tty_open_by_driver drivers/tty/tty_io.c:2073 [inline]
 tty_open+0xa63/0xfa0 drivers/tty/tty_io.c:2120
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:947
 vfs_open+0x82/0x3f0 fs/open.c:1079
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2873/0x4280 fs/namei.c:4859
 do_file_open+0x20e/0x430 fs/namei.c:4888
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1395
 do_sys_open fs/open.c:1401 [inline]
 __do_sys_openat fs/open.c:1417 [inline]
 __se_sys_openat fs/open.c:1412 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1412
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c2459ce59
RSP: 002b:00007f4c25400028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4c24815fa0 RCX: 00007f4c2459ce59
RDX: 0000000000101840 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007f4c24632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c24816038 R14: 00007f4c24815fa0 R15: 00007fff8738cfb8
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G     U       L      syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>