INFO: task hung in snd_seq_write
From: syzbot
Date: Mon Aug 27 2018 - 17:03:12 EST
Hello,
syzbot found the following crash on:
HEAD commit: e27bc174c9c6 Add linux-next specific files for 20180824
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1772020a400000
kernel config: https://syzkaller.appspot.com/x/.config?x=28446088176757ea
dashboard link: https://syzkaller.appspot.com/bug?extid=4c595632b98bb8ffcc66
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
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+4c595632b98bb8ffcc66@xxxxxxxxxxxxxxxxxxxxxxxxx
INFO: task syz-executor1:8015 blocked for more than 140 seconds.
Not tainted 4.18.0-next-20180824+ #47
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1 D25408 8015 4471 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021
__vfs_write+0x117/0x9d0 fs/read_write.c:485
vfs_write+0x1fc/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b
7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08
e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b
RSP: 002b:00007f5f1ec8fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f1ec906d4 RCX: 0000000000457089
RDX: 0000000000000020 RSI: 0000000020000480 RDI: 0000000000000006
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7388 R14: 00000000004c1780 R15: 0000000000000001
INFO: task syz-executor1:8019 blocked for more than 140 seconds.
Not tainted 4.18.0-next-20180824+ #47
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1 D25896 8019 4471 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021
__vfs_write+0x117/0x9d0 fs/read_write.c:485
vfs_write+0x1fc/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b
7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08
e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b
RSP: 002b:00007f5f1ec6ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f1ec6f6d4 RCX: 0000000000457089
RDX: 0000000000000090 RSI: 0000000020000580 RDI: 0000000000000003
RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7340 R14: 00000000004ca576 R15: 0000000000000002
INFO: task syz-executor1:8026 blocked for more than 140 seconds.
Not tainted 4.18.0-next-20180824+ #47
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1 D25112 8026 4471 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
__do_sys_ioctl fs/ioctl.c:709 [inline]
__se_sys_ioctl fs/ioctl.c:707 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b
7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08
e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b
RSP: 002b:00007f5f1ec4dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5f1ec4e6d4 RCX: 0000000000457089
RDX: 00000000200006c0 RSI: 00000000c08c5332 RDI: 0000000000000006
RBP: 0000000000930280 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cfed0 R14: 00000000004bf048 R15: 0000000000000003
INFO: task syz-executor1:8040 blocked for more than 140 seconds.
Not tainted 4.18.0-next-20180824+ #47
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1 D25896 8040 4471 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021
__vfs_write+0x117/0x9d0 fs/read_write.c:485
vfs_write+0x1fc/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b
7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08
e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b
RSP: 002b:00007f5f1ec2cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f1ec2d6d4 RCX: 0000000000457089
RDX: 00000000000000a0 RSI: 00000000200004c0 RDI: 0000000000000006
RBP: 0000000000930320 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7418 R14: 00000000004c1870 R15: 0000000000000004
INFO: task syz-executor1:8043 blocked for more than 140 seconds.
Not tainted 4.18.0-next-20180824+ #47
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1 D25896 8043 4471 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021
__vfs_write+0x117/0x9d0 fs/read_write.c:485
vfs_write+0x1fc/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b
7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08
e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b
RSP: 002b:00007f5f1ebeac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f1ebeb6d4 RCX: 0000000000457089
RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000006
RBP: 0000000000930460 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7790 R14: 00000000004ca7f1 R15: 0000000000000006
Showing all locks held in the system:
1 lock held by khungtaskd/776:
#0: 0000000098b2492f (rcu_read_lock){....}, at:
debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436
1 lock held by rsyslogd/4329:
2 locks held by getty/4419:
#0: 00000000a4856276 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000004b3fbd4e (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4420:
#0: 00000000d3776216 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 0000000018b91ba2 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4421:
#0: 00000000e90a323e (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000369e6155 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4422:
#0: 000000001139f51f (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000003aa121ca (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4423:
#0: 00000000dc25f399 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000009e2aa14c (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4424:
#0: 00000000fe22db15 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000249dec83 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4425:
#0: 000000002fbf78cf (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000000377af90 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
1 lock held by syz-executor1/7988:
1 lock held by syz-executor1/8015:
#0: 000000007dc4af24 (&client->ioctl_mutex){+.+.}, at:
snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021
1 lock held by syz-executor1/8019:
#0: 000000007dc4af24 (&client->ioctl_mutex){+.+.}, at:
snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021
1 lock held by syz-executor1/8026:
#0: 000000007dc4af24 (&client->ioctl_mutex){+.+.}, at:
snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137
1 lock held by syz-executor1/8040:
#0: 000000007dc4af24 (&client->ioctl_mutex){+.+.}, at:
snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021
1 lock held by syz-executor1/8043:
#0: 000000007dc4af24 (&client->ioctl_mutex){+.+.}, at:
snd_seq_write+0x1f1/0x8d0 sound/core/seq/seq_clientmgr.c:1021
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 776 Comm: khungtaskd Not tainted 4.18.0-next-20180824+ #47
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+0x1c9/0x2b4 lib/dump_stack.c:113
nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x151/0x192 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+0xb39/0x1040 kernel/hung_task.c:265
kthread+0x35a/0x420 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.319
msecs
NMI backtrace for cpu 0
CPU: 0 PID: 7988 Comm: syz-executor1 Not tainted 4.18.0-next-20180824+ #47
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:mark_lock+0x181/0x19f0 kernel/locking/lockdep.c:3155
Code: 43 10 00 00 00 00 48 8b 75 d0 65 48 33 34 25 28 00 00 00 0f 85 f5 11
00 00 48 81 c4 08 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d <c3> 48 c7 c7 a0
97 90 89 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48
RSP: 0018:ffff8801db0072e8 EFLAGS: 00000086
RAX: 0000000000000001 RBX: 0000000000000039 RCX: 1ffff100365035f1
RDX: 1ffffffff12853f6 RSI: 0000000000000000 RDI: ffffffff89429fb0
RBP: ffff8801db007680 R08: 0000000000000008 R09: 0000000000000001
R10: ffff8801b281a700 R11: ffff8801b281af2c R12: ffff8801b281af8a
R13: 0000000000000040 R14: ffff8801b281a700 R15: 000000000000000e
FS: 00007f5f1ecb1700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001c3883000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901
seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline]
read_seqcount_begin include/linux/seqlock.h:164 [inline]
ktime_get+0x14e/0x440 kernel/time/timekeeping.c:754
hrtimer_forward_now include/linux/hrtimer.h:473 [inline]
perf_swevent_hrtimer+0x405/0x510 kernel/events/core.c:9124
__run_hrtimer kernel/time/hrtimer.c:1398 [inline]
__hrtimer_run_queues+0x3eb/0xff0 kernel/time/hrtimer.c:1460
hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1029 [inline]
smp_apic_timer_interrupt+0x16d/0x6a0 arch/x86/kernel/apic/apic.c:1054
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:867
</IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783
[inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160
[inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa1/0xc0
kernel/locking/spinlock.c:184
Code: 68 bc f1 87 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c
02 00 75 21 48 83 3d 2e be 3a 01 00 74 0e 48 89 df 57 9d <0f> 1f 44 00 00
eb bb 0f 0b 0f 0b e8 cf 10 05 fb eb 97 e8 c8 10 05
RSP: 0018:ffff88019430f7b0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 0000000000000282 RCX: 1ffff100365035ec
RDX: 1ffffffff0fe378d RSI: 0000000000000000 RDI: 0000000000000282
RBP: ffff88019430f7c0 R08: ffff8801b281af40 R09: 0000000000000006
R10: ffff8801b281a700 R11: 0000000000000000 R12: ffffffff8861fc20
R13: ffff8801b0156540 R14: 0000000000000282 R15: ffffffff8a34a020
spin_unlock_irqrestore include/linux/spinlock.h:384 [inline]
snd_seq_client_use_ptr+0x9e/0x3f0 sound/core/seq/seq_clientmgr.c:178
snd_seq_dispatch_event+0xbf/0x650 sound/core/seq/seq_clientmgr.c:845
snd_seq_check_queue.part.4+0x139/0x360 sound/core/seq/seq_queue.c:275
snd_seq_check_queue sound/core/seq/seq_queue.c:255 [inline]
snd_seq_enqueue_event+0x346/0x4d0 sound/core/seq/seq_queue.c:343
snd_seq_client_enqueue_event+0x2a5/0x510 sound/core/seq/seq_clientmgr.c:957
snd_seq_write+0x3f1/0x8d0 sound/core/seq/seq_clientmgr.c:1074
__vfs_write+0x117/0x9d0 fs/read_write.c:485
vfs_write+0x1fc/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5f1ecb0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f1ecb16d4 RCX: 0000000000457089
RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7790 R14: 00000000004ca7f1 R15: 0000000000000000
---
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