INFO: task syz-executor0:12313 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc4-next-20180713+ #7
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D23400 12313   4484 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2848 [inline]
 __schedule+0x87c/0x1ed0 kernel/sched/core.c:3496
 schedule+0xfb/0x450 kernel/sched/core.c:3540
 __rwsem_down_write_failed_common+0x95d/0x1630 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+0xaa/0x130 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:752 [inline]
 chmod_common+0x1b1/0x590 fs/open.c:535
 do_fchmodat+0xc3/0x160 fs/open.c:579
 __do_sys_chmod fs/open.c:597 [inline]
 __se_sys_chmod fs/open.c:595 [inline]
 __x64_sys_chmod+0x5c/0x80 fs/open.c:595
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455ab9
Code: e0 1f 48 89 04 24 e8 b6 6f fd ff e8 81 6a fd ff e8 5c 68 fd ff 48 8d 05 92 9a 48 00 48 89 04 24 48 c7 44 24 08 1d 00 00 00 e8 <13> 5e fd ff 0f 0b e8 8c 44 00 00 e9 07 f0 ff ff cc cc cc cc cc cc 
RSP: 002b:00007fb85efb8c68 EFLAGS: 00000246 ORIG_RAX: 000000000000005a
RAX: ffffffffffffffda RBX: 00007fb85efb96d4 RCX: 0000000000455ab9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200004c0
RBP: 000000000072bff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004bb0de R14: 00000000004c8c68 R15: 0000000000000002
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 902 Comm: khungtaskd Not tainted 4.18.0-rc4-next-20180713+ #7
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:231 [inline]
 watchdog+0xb81/0x10f0 kernel/hung_task.c:292
 kthread+0x345/0x410 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