INFO: task syz.8.628:8926 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.628       state:D stack:26864 pid: 8926 ppid:  8513 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093
 __down_common+0x289/0x3b0 kernel/locking/semaphore.c:228
 down+0x7e/0xd0 kernel/locking/semaphore.c:63
 console_lock+0x29/0x70 kernel/printk/printk.c:2557
 paste_selection+0xee/0x4e0 drivers/tty/vt/selection.c:383
 vt_ioctl+0x441/0x1ca0 drivers/tty/vt/vt_ioctl.c:764
 tty_ioctl+0x848/0xc30 drivers/tty/tty_io.c:2810
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd8432ae159
RSP: 002b:00007fd8414e5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd843536090 RCX: 00007fd8432ae159
RDX: 0000200000000200 RSI: 000000000000541c RDI: 0000000000000005
RBP: 00007fd84334506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd843536128 R14: 00007fd843536090 R15: 00007fff34b32d68
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/0:1H/151:
2 locks held by getty/3942:
 #0: ffff88814cd43098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
2 locks held by kworker/u4:7/4280:
 #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900031ffd00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
5 locks held by syz.3.547/8341:
3 locks held by kworker/0:22/8375:
4 locks held by syz.4.819/9998:
 #0: ffff888062e8e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffff888016de00b8 (&buf->lock){+.+.}-{3:3}, at: tiocsti+0x192/0x270 drivers/tty/tty_io.c:2310
 #2: ffff888062e8e2e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_receive_buf_common+0x87/0x65b0 drivers/tty/n_tty.c:1637
 #3: ffffc90001e81378 (&ldata->output_lock){+.+.}-{3:3}, at: commit_echoes drivers/tty/n_tty.c:775 [inline]
 #3: ffffc90001e81378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_receive_char_special drivers/tty/n_tty.c:1309 [inline]
 #3: ffffc90001e81378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_receive_buf_standard drivers/tty/n_tty.c:1558 [inline]
 #3: ffffc90001e81378 (&ldata->output_lock){+.+.}-{3:3}, at: __receive_buf drivers/tty/n_tty.c:1577 [inline]
 #3: ffffc90001e81378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_receive_buf_common+0x3762/0x65b0 drivers/tty/n_tty.c:1674
1 lock held by syz.3.876/10294:
3 locks held by modprobe/10361:
1 lock held by syz.0.899/10364:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>