INFO: task syz-executor1:9568 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc7-next-20180803+ #31
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D25408  9568   4349 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2823 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3471
 schedule+0xfb/0x450 kernel/sched/core.c:3515
 __rwsem_down_write_failed_common+0x98b/0x1650 kernel/locking/rwsem-xadd.c:566
 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595
 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117
 __down_write arch/x86/include/asm/rwsem.h:142 [inline]
 down_write_nested+0xae/0x130 kernel/locking/rwsem.c:194
 inode_lock_nested include/linux/fs.h:803 [inline]
 do_unlinkat+0x3d8/0xa30 fs/namei.c:4049
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink fs/namei.c:4108 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4108
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456b29
Code: 42 08 84 00 48 83 c0 58 48 89 04 24 e8 00 8b fb ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 91 33 00 00 eb bf cc cc cc cc cc cc cc cc <cc> cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 2b
RSP: 002b:00007fd47b7ebc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007fd47b7ec6d4 RCX: 0000000000456b29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000300
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d6110 R14: 00000000004c71c7 R15: 0000000000000001
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 774 Comm: khungtaskd Not tainted 4.18.0-rc7-next-20180803+ #31
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+0xb39/0x10b0 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 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54