INFO: task syz.8.511:6842 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.511       state:D stack:27120 pid: 6842 ppid:  6330 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
 con_install+0x94/0x720 drivers/tty/vt/vt.c:3381
 tty_driver_install_tty drivers/tty/tty_io.c:1317 [inline]
 tty_init_dev+0xbb/0x470 drivers/tty/tty_io.c:1431
 tty_open_by_driver drivers/tty/tty_io.c:2100 [inline]
 tty_open+0x7e8/0xcd0 drivers/tty/tty_io.c:2148
 chrdev_open+0x585/0x5f0 fs/char_dev.c:414
 do_dentry_open+0x7f7/0xf90 fs/open.c:826
 do_open fs/namei.c:3616 [inline]
 path_openat+0x2718/0x2fb0 fs/namei.c:3750
 do_filp_open+0x1df/0x400 fs/namei.c:3777
 do_sys_openat2+0x14b/0x500 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_openat fs/open.c:1287 [inline]
 __se_sys_openat fs/open.c:1282 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1282
 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: 0033:0x7f962e2ff90e
RSP: 002b:00007f962c596b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f962c5976c0 RCX: 00007f962e2ff90e
RDX: 0000000000000002 RSI: 00007f962c596c00 RDI: ffffffffffffff9c
RBP: 00007f962e3d6024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f962e5c7038 R14: 00007f962e5c6fa0 R15: 00007fff48cf9378
 </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
1 lock held by udevd/3559:
2 locks held by getty/3943:
 #0: ffff88814cef9098 (&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
3 locks held by kworker/0:4/4230:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900030efd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
2 locks held by kworker/0:5/4231:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900030ffd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
3 locks held by kworker/0:7/4263:
2 locks held by kworker/u4:10/4355:
 #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900011efd00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
3 locks held by kworker/u4:12/4433:
2 locks held by kworker/u4:15/4825:
3 locks held by kworker/0:8/5385:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000402fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88801ed3e240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x283/0x3380 drivers/net/netdevsim/fib.c:1480
5 locks held by syz.7.500/6803:
2 locks held by syz.8.511/6842:
 #0: ffffffff8c9f62e8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2064 [inline]
 #0: ffffffff8c9f62e8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x20a/0xcd0 drivers/tty/tty_io.c:2148
 #1: ffff88801fe731c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_init_dev+0x6f/0x470 drivers/tty/tty_io.c:1430
1 lock held by syz-executor/7040:
 #0: ffff88814cad8d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x5e/0x360 net/netfilter/x_tables.c:1265
1 lock held by syz.5.564/7110:
 #0: ffffffff8c9f62e8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2064 [inline]
 #0: ffffffff8c9f62e8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x20a/0xcd0 drivers/tty/tty_io.c:2148
1 lock held by syz-executor/7334:
1 lock held by syz.0.601/7388:
 #0: ffffffff8c9f62e8 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0xd2/0x2c0 drivers/tty/pty.c:823
2 locks held by kworker/u4:0/7451:
 #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000313fd00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
1 lock held by syz.3.633/7592:
 #0: ffffffff8c9f62e8 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0xd2/0x2c0 drivers/tty/pty.c:823
1 lock held by syz-executor/7695:
 #0: ffff88814cad8d88 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x5e/0x360 net/netfilter/x_tables.c:1265
1 lock held by syz.2.658/7761:
 #0: ffffffff8c9f62e8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2064 [inline]
 #0: ffffffff8c9f62e8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x20a/0xcd0 drivers/tty/tty_io.c:2148
1 lock held by rm/7866:
2 locks held by syz-executor/7871:

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

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 07/24/2026
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>