devpts: called with bogus options INFO: task getty:7034 blocked for more than 140 seconds. Not tainted 4.14.160-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. getty D25920 7034 1 0x80000002 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384 schedule+0x92/0x1c0 kernel/sched/core.c:3428 schedule_timeout+0x93b/0xe10 kernel/time/timer.c:1723 down_write_failed drivers/tty/tty_ldsem.c:298 [inline] __ldsem_down_write_nested+0x304/0x7b0 drivers/tty/tty_ldsem.c:360 ldsem_down_write+0x33/0x39 drivers/tty/tty_ldsem.c:402 __tty_ldisc_lock drivers/tty/tty_ldisc.c:332 [inline] tty_ldisc_lock+0x50/0x80 drivers/tty/tty_ldisc.c:356 tty_ldisc_hangup+0x1a6/0x5e0 drivers/tty/tty_ldisc.c:758 __tty_hangup.part.0+0x2d3/0x6d0 drivers/tty/tty_io.c:622 __tty_hangup drivers/tty/tty_io.c:572 [inline] tty_vhangup_session+0x25/0x30 drivers/tty/tty_io.c:732 disassociate_ctty.part.0+0x9b/0x6c0 drivers/tty/tty_jobctrl.c:266 disassociate_ctty+0x78/0x90 drivers/tty/tty_jobctrl.c:260 do_exit+0x1799/0x2c80 kernel/exit.c:852 do_group_exit+0x111/0x330 kernel/exit.c:951 SYSC_exit_group kernel/exit.c:962 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:960 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7efeb122c1e8 RSP: 002b:00007ffdafde4368 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007efeb122c1e8 RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007efeb1501840 R08: 00000000000000e7 R09: ffffffffffffffa8 R10: 00007efeb1507740 R11: 0000000000000246 R12: 00007efeb1501840 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 INFO: task kworker/u4:7:13517 blocked for more than 140 seconds. Not tainted 4.14.160-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:7 D26064 13517 2 0x80000000 Workqueue: events_unbound flush_to_ldisc Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384 schedule+0x92/0x1c0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 flush_to_ldisc+0x39/0x400 drivers/tty/tty_buffer.c:499 process_one_work+0x863/0x1600 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task syz-executor.0:23066 blocked for more than 140 seconds. Not tainted 4.14.160-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28544 23066 7081 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384 schedule+0x92/0x1c0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 tty_buffer_lock_exclusive+0x1f/0x30 drivers/tty/tty_buffer.c:60 paste_selection+0x106/0x3f2 drivers/tty/vt/selection.c:349 tioclinux+0x10e/0x400 drivers/tty/vt/vt.c:2696 vt_ioctl+0x180c/0x2170 drivers/tty/vt/vt_ioctl.c:364 tty_ioctl+0x841/0x1320 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a919 RSP: 002b:00007f57123cac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919 RDX: 0000000020000040 RSI: 000000000000541c RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f57123cb6d4 R13: 00000000004c5c8b R14: 00000000004dc060 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1046: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544 2 locks held by getty/7034: #0: (&tty->legacy_mutex){+.+.}, at: [] tty_lock+0x68/0x80 drivers/tty/tty_mutex.c:19 #1: (&tty->ldisc_sem){++++}, at: [] ldsem_down_write+0x33/0x39 drivers/tty/tty_ldsem.c:402 2 locks held by getty/7035: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7036: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7037: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7038: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7039: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 2 locks held by getty/7040: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:7/13517: #0: ("events_unbound"){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("events_unbound"){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("events_unbound"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("events_unbound"){+.+.}, at: [] process_one_work+0x76e/0x1600 kernel/workqueue.c:2085 #1: ((&buf->work)){+.+.}, at: [] process_one_work+0x7ab/0x1600 kernel/workqueue.c:2089 #2: (&buf->lock){+.+.}, at: [] flush_to_ldisc+0x39/0x400 drivers/tty/tty_buffer.c:499 2 locks held by syz-executor.0/23066: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&buf->lock){+.+.}, at: [] tty_buffer_lock_exclusive+0x1f/0x30 drivers/tty/tty_buffer.c:60 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1046 Comm: khungtaskd Not tainted 4.14.160-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 23063 Comm: syz-executor.1 Not tainted 4.14.160-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888052e182c0 task.stack: ffff8880a10a0000 RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x60 kernel/kcov.c:85 RSP: 0018:ffff8880a10a7740 EFLAGS: 00000046 RAX: ffff888052e182c0 RBX: ffffffff88337d80 RCX: 0000000000000002 RDX: 0000000000000001 RSI: ffffffff830afe29 RDI: ffff888052e18b3c RBP: ffff8880a10a7740 R08: 000000eaa329c12f R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880aec2b5e0 R13: ffff888052e182c0 R14: ffff888052e18390 R15: 0000000000000c34 FS: 00007fc851ff1700(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c43458d8f0 CR3: 000000008415b000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_smp_processor_id+0x9/0x20 lib/smp_processor_id.c:57 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:360 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:1130 rcu_read_lock_sched_held+0x8e/0x130 kernel/rcu/update.c:111 trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] update_curr+0x53c/0x6a0 kernel/sched/fair.c:855 pick_next_task_fair+0x661/0x1430 kernel/sched/fair.c:6303 pick_next_task kernel/sched/core.c:3232 [inline] __schedule+0x43e/0x1cd0 kernel/sched/core.c:3357 schedule+0x92/0x1c0 kernel/sched/core.c:3428 paste_selection+0x293/0x3f2 drivers/tty/vt/selection.c:355 tioclinux+0x10e/0x400 drivers/tty/vt/vt.c:2696 vt_ioctl+0x180c/0x2170 drivers/tty/vt/vt_ioctl.c:364 tty_ioctl+0x841/0x1320 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a919 RSP: 002b:00007fc851ff0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919 RDX: 0000000020000040 RSI: 000000000000541c RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc851ff16d4 R13: 00000000004c5c8b R14: 00000000004dc060 R15: 00000000ffffffff Code: ee 01 00 48 85 c0 74 1a 65 8b 15 4b 9e a4 7e 81 e2 00 01 1f 00 75 0b 8b 90 50 13 00 00 83 fa 01 74 01 c3 55 48 89 e5 48 8b 75 08 <48> 8b 88 58 13 00 00 8b 80 54 13 00 00 48 8b 11 48 83 c2 01 48