INFO: task hung in evdev_flush

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 58a022870787 Merge tag 'acpi-4.20-rc1' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1083e213400000
kernel config: https://syzkaller.appspot.com/x/.config?x=414a8e66ba2c6789
dashboard link: https://syzkaller.appspot.com/bug?extid=37bc9cbc8147e5f37612
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [dmitry....@gmail.com linux...@vger.kernel.org
linux-...@vger.kernel.org ryd...@bitmath.org]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+37bc9c...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
INFO: task syz-executor5:24267 blocked for more than 140 seconds.
Not tainted 4.19.0+ #299
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5 D23216 24267 19653 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
schedule+0xfe/0x460 kernel/sched/core.c:3517
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
evdev_flush+0x74/0x150 drivers/input/evdev.c:356
filp_close+0x154/0x250 fs/open.c:1140
__close_fd+0x245/0x3a0 fs/file.c:635
__do_sys_close fs/open.c:1159 [inline]
__se_sys_close fs/open.c:1157 [inline]
__x64_sys_close+0x72/0xf0 fs/open.c:1157
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x411021
Code: 83 c4 40 c3 48 8d 05 16 ef 48 00 48 89 04 24 48 c7 44 24 08 0d 00 00
00 e8 ac a8 01 00 0f 0b 48 8d 05 fb ee 48 00 48 89 04 24 <48> c7 44 24 08
0d 00 00 00 e8 91 a8 01 00 0f 0b e8 1a 8f 04 00 e9
RSP: 002b:0000000000a3fd90 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000411021
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000005
RBP: 0000000000000000 R08: 000000008136d717 R09: 0000000000000000
R10: 0000000000a3fcc0 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000001 R14: 000000000000009d R15: 0000000000000005
INFO: task syz-executor2:24268 blocked for more than 140 seconds.
Not tainted 4.19.0+ #299
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2 D23216 24268 19652 0x00000006
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
schedule+0xfe/0x460 kernel/sched/core.c:3517
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
evdev_close_device drivers/input/evdev.c:447 [inline]
evdev_release+0xfe/0x1e0 drivers/input/evdev.c:488
__fput+0x385/0xa30 fs/file_table.c:278
____fput+0x15/0x20 fs/file_table.c:309
task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
get_signal+0x155e/0x1980 kernel/signal.c:2343
do_signal+0x9c/0x21e0 arch/x86/kernel/signal.c:816
exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x411021
Code: 83 c4 40 c3 48 8d 05 16 ef 48 00 48 89 04 24 48 c7 44 24 08 0d 00 00
00 e8 ac a8 01 00 0f 0b 48 8d 05 fb ee 48 00 48 89 04 24 <48> c7 44 24 08
0d 00 00 00 e8 91 a8 01 00 0f 0b e8 1a 8f 04 00 e9
RSP: 002b:0000000000a3fd90 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000411021
RDX: 0000000000000000 RSI: 0000000000730590 RDI: 0000000000000005
RBP: 0000000000000000 R08: 000000008136d717 R09: 0000000000000000
R10: 0000000000a3fcc0 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000001 R14: 00000000000000a0 R15: 0000000000000002

Showing all locks held in the system:
1 lock held by khungtaskd/983:
#0: 00000000dfdb1c39 (rcu_read_lock){....}, at:
debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435
1 lock held by rsyslogd/5201:
#0: 000000004b45dd49 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200
fs/file.c:766
2 locks held by getty/5301:
#0: 00000000344b756b (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000002a520fb4 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5302:
#0: 0000000092a5dac3 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000006e9f10d2 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5303:
#0: 000000005453fcca (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000005356277c (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5304:
#0: 00000000a03374e3 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000f0617115 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5305:
#0: 00000000af0b7cb6 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000081ce3eb (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5306:
#0: 00000000f812d058 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000007781f212 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5307:
#0: 000000007ee041f5 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 0000000030b5d607 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
1 lock held by syz-executor5/24267:
#0: 000000004d2581fa (&evdev->mutex){+.+.}, at: evdev_flush+0x74/0x150
drivers/input/evdev.c:356
1 lock held by syz-executor2/24268:
#0: 000000004d2581fa (&evdev->mutex){+.+.}, at: evdev_close_device
drivers/input/evdev.c:447 [inline]
#0: 000000004d2581fa (&evdev->mutex){+.+.}, at: evdev_release+0xfe/0x1e0
drivers/input/evdev.c:488
1 lock held by syz-executor0/24275:
#0: 000000004d2581fa (&evdev->mutex){+.+.}, at:
evdev_ioctl_handler+0x82/0x1a0 drivers/input/evdev.c:1298

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

NMI backtrace for cpu 1
CPU: 1 PID: 983 Comm: khungtaskd Not tainted 4.19.0+ #299
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c4/0x2b6 lib/dump_stack.c:113
nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
watchdog+0xb3e/0x1050 kernel/hung_task.c:265
kthread+0x35a/0x420 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
Sending NMI from CPU 1 to CPUs 0:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.210
msecs
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0+ #299
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__write_once_size include/linux/compiler.h:215 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4b/0x50 kernel/kcov.c:109
Code: 90 d0 12 00 00 83 fa 02 75 20 48 8b 88 d8 12 00 00 8b 80 d4 12 00 00
48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 <5d> c3 0f 1f 00
55 40 0f b6 d6 40 0f b6 f7 31 ff 48 89 e5 48 8b 4d
RSP: 0018:ffff8801dae07a20 EFLAGS: 00000006
RAX: ffffffff89276e40 RBX: 1ffff1003b5c0f49 RCX: ffffffff8184c05a
RDX: 0000000000000100 RSI: ffffffff8184c0b6 RDI: 0000000000000005
RBP: ffff8801dae07a20 R08: ffffffff89276e40 R09: 0000000000000001
R10: fffffbfff1460001 R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff89276e40 R14: ffff8801dae07e68 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001c7c7e000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
trace_hardirqs_on+0xf6/0x310 kernel/trace/trace_preemptirq.c:25
__do_softirq+0x298/0xb03 kernel/softirq.c:276
invoke_softirq kernel/softirq.c:372 [inline]
irq_exit+0x17f/0x1c0 kernel/softirq.c:412
scheduler_ipi+0x55a/0xad0 kernel/sched/core.c:1780
smp_reschedule_interrupt+0x109/0x650 arch/x86/kernel/smp.c:278
reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:888
</IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57
Code: e9 2c ff ff ff 48 89 c7 48 89 45 d8 e8 a3 1c 11 fa 48 8b 45 d8 e9 ca
fe ff ff 48 89 df e8 92 1c 11 fa eb 82 55 48 89 e5 fb f4 <5d> c3 0f 1f 84
00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90
RSP: 0018:ffffffff89207bb8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: 1ffffffff1240f7b RCX: 0000000000000000
RDX: 1ffffffff1263e44 RSI: 0000000000000001 RDI: ffffffff8931f220
RBP: ffffffff89207bb8 R08: ffffffff89276e40 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89207c78
R13: ffffffff89f3f120 R14: 0000000000000000 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
default_idle+0xbf/0x490 arch/x86/kernel/process.c:498
arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489
default_idle_call+0x6d/0x90 kernel/sched/idle.c:93
cpuidle_idle_call kernel/sched/idle.c:153 [inline]
do_idle+0x3db/0x5b0 kernel/sched/idle.c:262
cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368
rest_init+0xe2/0xe5 init/main.c:442
start_kernel+0x8f4/0x92f init/main.c:739
x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470
x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.