INFO: task syz.6.943:6952 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.943       state:D stack:29040 pid: 6952 ppid:  5797 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: 0033:0x7fd4242a51d9
RSP: 002b:00007fd4224dc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd42452d090 RCX: 00007fd4242a51d9
RDX: 0000200000000000 RSI: 000000000000541c RDI: 0000000000000003
RBP: 00007fd42433c888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd42452d128 R14: 00007fd42452d090 R15: 00007fff72825e08
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8d11efa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u4:2/154:
2 locks held by getty/3945:
 #0: ffff88802cff7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by udevd/4180:
3 locks held by kworker/0:5/4230:
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000313fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88804a349240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x283/0x3380 drivers/net/netdevsim/fib.c:1480
2 locks held by kworker/u4:5/4251:
2 locks held by kworker/0:12/4816:
 #0: ffff888017872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000345fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
2 locks held by kworker/0:16/4820:
 #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000349fd00 (console_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
2 locks held by syz-executor/5756:
2 locks held by syz.6.943/6949:
1 lock held by syz.7.1091/7522:
 #0: ffffffff8d7fe0e8 (vc_sel.lock){+.+.}-{3:3}, at: set_selection_kernel+0x32/0x17a0 drivers/tty/vt/selection.c:357
4 locks held by syz.3.1373/8633:
 #0: ffff888060ce9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffff888060ce9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:961 [inline]
 #1: ffff888060ce9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: do_tty_write drivers/tty/tty_io.c:984 [inline]
 #1: ffff888060ce9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: file_tty_write+0x23c/0x8a0 drivers/tty/tty_io.c:1110
 #2: ffff888060ce92e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_write+0x1ec/0x1220 drivers/tty/n_tty.c:2322
 #3: ffffc9000129d378 (&ldata->output_lock){+.+.}-{3:3}, at: process_output_block drivers/tty/n_tty.c:547 [inline]
 #3: ffffc9000129d378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_write+0x66a/0x1220 drivers/tty/n_tty.c:2339
1 lock held by syz.8.2163/11202:
 #0: ffffffff8d7fe0e8 (vc_sel.lock){+.+.}-{3:3}, at: set_selection_kernel+0x32/0x17a0 drivers/tty/vt/selection.c:357
1 lock held by syz.8.2163/11204:
 #0: ffffffff8d7fe0e8 (vc_sel.lock){+.+.}-{3:3}, at: set_selection_kernel+0x32/0x17a0 drivers/tty/vt/selection.c:357
1 lock held by syz-executor/11651:
 #0: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffffffff8d123a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
3 locks held by syz.4.2332/11890:
1 lock held by syz.0.2336/11922:
2 locks held by sed/11935:

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

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 10/07/2026
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>