INFO: task syz-executor0:5068 blocked for more than 120 seconds.
      Not tainted 4.4.115-g55a366596 #14
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D ffff8800b10bfb68 29400  5068   3763 0x00000002
 ffff8800b10bfb68 0000000000000000 0000000000000000 0000000000000000
 0000000000000001 ffff8800b10bfb00 ffff8801db31fdb8 ffff8801db31fde0
 ffff8801db31f4d8 ffff8801c9c76000 ffff8801cbbac800 0000000000000000
Call Trace:
 [<ffffffff837663ba>] schedule+0x7a/0x1b0 kernel/sched/core.c:3353
 [<ffffffff83766bb3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3386
 [<ffffffff8376b176>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8376b176>] mutex_lock_nested+0x306/0x850 kernel/locking/mutex.c:621
 [<ffffffff82d427da>] odev_release+0x4a/0x70 sound/core/seq/oss/seq_oss.c:151
 [<ffffffff81523693>] __fput+0x233/0x6d0 fs/file_table.c:208
 [<ffffffff81523bb5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118b9e4>] task_work_run+0x104/0x180 kernel/task_work.c:115
 [<ffffffff81132f8a>] exit_task_work include/linux/task_work.h:21 [inline]
 [<ffffffff81132f8a>] do_exit+0x82a/0x2a10 kernel/exit.c:755
 [<ffffffff81139428>] do_group_exit+0x108/0x320 kernel/exit.c:885
 [<ffffffff8113965d>] SYSC_exit_group kernel/exit.c:896 [inline]
 [<ffffffff8113965d>] SyS_exit_group+0x1d/0x20 kernel/exit.c:894
 [<ffffffff837744df>] entry_SYSCALL_64_fastpath+0x1c/0x98
INFO: lockdep is turned off.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 485 Comm: khungtaskd Not tainted 4.4.115-g55a366596 #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bac28000 task.stack: ffff8800bb0c8000
RIP: 0010:[<ffffffff810c3eb7>]  [<ffffffff810c3eb7>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810c3eb7>]  [<ffffffff810c3eb7>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810c3eb7>]  [<ffffffff810c3eb7>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810c3eb7>]  [<ffffffff810c3eb7>] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bb0cfcb8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: ffffffff8126a2f2
RDX: 0000000000000c00 RSI: 0000000000000002 RDI: ffffffffff5fb300
RBP: ffff8800bb0cfce0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: fffffbfff0ad7e2c R12: 0000000000000246
R13: 0000000000000003 R14: ffffffff8426f3a0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd9f0ce9000 CR3: 00000000aec5c000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8426f3a0 ffffffff847ef7c0 fffffbfff08fd9ac dffffc0000000000
 ffff8801db31bca0 ffff8800bb0cfd00 ffffffff810b99eb ffffffff839f6200
 0000000000000003 ffff8800bb0cfd60 ffffffff81d0ecf4 0000000000000001
Call Trace:
 [<ffffffff810b99eb>] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81d0ecf4>] nmi_trigger_all_cpu_backtrace+0x4a4/0x550 lib/nmi_backtrace.c:85
 [<ffffffff810b9a84>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff81368cba>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff81368cba>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81368cba>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81368cba>] watchdog+0x6fa/0xae0 kernel/hung_task.c:238
 [<ffffffff811907e8>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff83774905>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:506
Code: b3 5f ff f6 c4 10 75 e1 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 74 1a e8 7b 2f 17 00 4c 89 e7 57 9d 0f 1f 
NMI backtrace for cpu 1
CPU: 1 PID: 3539 Comm: rsyslogd Not tainted 4.4.115-g55a366596 #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cd87c800 task.stack: ffff8800b0c10000
RIP: 0010:[<ffffffff8123d7a6>]  [<ffffffff8123d7a6>] lock_acquire+0xd6/0x460 kernel/locking/lockdep.c:3590
RSP: 0018:ffff8800b0c179f8  EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8801db31f4d8 RCX: 0000000000000000
RDX: ffff8801cd87c800 RSI: 0000000000000000 RDI: ffff8801cd87d0cc
RBP: ffff8800b0c17a70 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff83844400 R11: ffffffff847ebc38 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS:  00007f73bdbb1700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa44cdab9b8 CR3: 00000000aec5c000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d9b49800 ffff8800b0c17ac0 ffffffff8100b3b7 0000000000000046
 ffff8801cd87c860 ffff8800b0c17a60 ffffffff81d63b3b ffff880100000001
 0000000000000000 0000000000000046 ffff8801db31f4c0 ffff8801d9b49800
Call Trace:
 [<ffffffff811a438f>] finish_lock_switch kernel/sched/sched.h:1173 [inline]
 [<ffffffff811a438f>] finish_task_switch+0x1df/0x4e0 kernel/sched/core.c:2676
 [<ffffffff83764fe8>] context_switch kernel/sched/core.c:2805 [inline]
 [<ffffffff83764fe8>] __schedule+0xac8/0x1ca0 kernel/sched/core.c:3324
 [<ffffffff837663ba>] schedule+0x7a/0x1b0 kernel/sched/core.c:3353
 [<ffffffff81268e52>] do_syslog+0x592/0xae0 kernel/printk/printk.c:1327
 [<ffffffff8168ef14>] kmsg_read+0x74/0xa0 fs/proc/kmsg.c:39
 [<ffffffff81665d1f>] proc_reg_read+0xef/0x170 fs/proc/inode.c:202
 [<ffffffff8151cfc3>] __vfs_read+0x103/0x440 fs/read_write.c:432
 [<ffffffff8151ee63>] vfs_read+0x123/0x3a0 fs/read_write.c:454
 [<ffffffff815217a9>] SYSC_read fs/read_write.c:569 [inline]
 [<ffffffff815217a9>] SyS_read+0xd9/0x1b0 fs/read_write.c:562
 [<ffffffff837744df>] entry_SYSCALL_64_fastpath+0x1c/0x98
Code: 03 38 c8 7c 08 84 c9 0f 85 a7 02 00 00 8b 05 3a f6 59 03 49 c7 c2 00 44 84 83 c7 82 cc 08 00 00 01 00 00 00 4c 8b 1d 5a 6c 60 02 <85> c0 0f 8f 1a 01 00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 d0