INFO: task login:7531 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.
login D28096 7531 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: 0033:0x7fd80303a1e8
RSP: 002b:00007ffe772104e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd80303a1e8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00007fd80330f840 R08: 00000000000000e7 R09: ffffffffffffffa8
R10: 00007fd803315740 R11: 0000000000000246 R12: 00007fd80330f840
R13: 0000000000000001 R14: 0000000000000001 R15: 000000000060b798
Showing all locks held in the system:
1 lock held by khungtaskd/1038:
#0: (tasklist_lock){.+.+}, at: [<ffffffff8148c8d8>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544
2 locks held by getty/7014:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff8664f823>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83491c76>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7015:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff8664f823>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83491c76>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7016:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff8664f823>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83491c76>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7017:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff8664f823>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83491c76>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7018:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff8664f823>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83491c76>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by getty/7019:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff8664f823>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff83491c76>] n_tty_read+0x1e6/0x17d0 drivers/tty/n_tty.c:2156
2 locks held by login/7531:
#0: (&tty->legacy_mutex){+.+.}, at: [<ffffffff834a4478>] tty_lock+0x68/0x80 drivers/tty/tty_mutex.c:19
#1: (&tty->ldisc_sem){++++}, at: [<ffffffff8664f863>] ldsem_down_write+0x33/0x39 drivers/tty/tty_ldsem.c:402
3 locks held by syz-executor619/7613:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff8664f823>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
#1: (&buf->lock){+.+.}, at: [<ffffffff834a043f>] tty_buffer_lock_exclusive+0x1f/0x30 drivers/tty/tty_buffer.c:60
#2: (&rq->lock){-.-.}, at: [<ffffffff8663d86a>] rq_lock kernel/sched/sched.h:1741 [inline]
#2: (&rq->lock){-.-.}, at: [<ffffffff8663d86a>] __schedule+0x1da/0x1cd0 kernel/sched/core.c:3321
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 1038 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: 7613 Comm: syz-executor619 Not tainted 4.14.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880848f8480 task.stack: ffff88809f2c0000
RIP: 0010:trace_hardirqs_on+0xd/0x10 kernel/locking/lockdep.c:2934
RSP: 0018:ffff88809f2c78c8 EFLAGS: 00000046
RAX: 0000000000000007 RBX: ffff8880848f8aa0 RCX: 1ffff1101091f1a9
RDX: 0000000000000000 RSI: ffff8880848f8d28 RDI: ffff8880848f8cfc
RBP: ffff88809f2c78c8 R08: ffff8880848f8480 R09: ffff8880848f8d48
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aec2b540
R13: ffff88809f2c7950 R14: ffff8880848f8480 R15: ffff8880aec2b540
FS: 0000000002456880(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000dce000 CR3: 00000000a51a5000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
_raw_spin_unlock_irq+0x28/0x90 kernel/locking/spinlock.c:200
rq_unlock_irq kernel/sched/sched.h:1766 [inline]
__schedule+0x137b/0x1cd0 kernel/sched/core.c:3387
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: 0033:0x441219
RSP: 002b:00007fff3a25af58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441219
RDX: 0000000020000040 RSI: 000000000000541c RDI: 0000000000000003
RBP: 00000000000cf93c R08: 000000000000000d R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402040
R13: 00000000004020d0 R14: 0000000000000000 R15: 0000000000000000
Code: 89 e8 68 9b 3f 00 e9 63 fe ff ff 48 c7 c7 20 3f b6 89 e8 57 9b 3f 00 e9 ba fe ff ff 66 90 55 48 89 e5 48 8b 7d 08 e8 63 fa ff ff <5d> c3 90 55 48 89 e5 41 57 41 56 41 55 41 54 49 89 fc 53 89 d3