======================================================
[ INFO: possible circular locking dependency detected ]
4.9.71-g2506378 #113 Not tainted
-------------------------------------------------------
syz-executor4/12220 is trying to acquire lock:
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 0 PID: 12230 Comm: syz-executor2 Not tainted 4.9.71-g2506378 #113
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c1f5f8f0 ffffffff81d922b9 ffff8801c1f5fbd0 0000000000000000
 ffff8801c229c410 ffff8801c1f5fac0 ffff8801c229c300 ffff8801c1f5fae8
 ffffffff8165fb7a 0000000000000000 ffff8801c1f5fa40 00000001d0d3a067
Call Trace:
 [<ffffffff81d922b9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d922b9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8165fb7a>] handle_userfault+0xa3a/0x1310 fs/userfaultfd.c:323
 [<ffffffff814cea81>] do_anonymous_page mm/memory.c:2747 [inline]
 [<ffffffff814cea81>] handle_pte_fault mm/memory.c:3488 [inline]
 [<ffffffff814cea81>] __handle_mm_fault mm/memory.c:3577 [inline]
 [<ffffffff814cea81>] handle_mm_fault+0x1fd1/0x2530 mm/memory.c:3614
 [<ffffffff810dd462>] __do_page_fault+0x5c2/0xd40 arch/x86/mm/fault.c:1406
 [<ffffffff810ddc07>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1469
 [<ffffffff838b0158>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1007
 [<ffffffff838aef85>] entry_SYSCALL_64_fastpath+0x23/0xc6
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 0 PID: 12219 Comm: syz-executor2 Not tainted 4.9.71-g2506378 #113
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c2057930 ffffffff81d922b9 ffff8801c2057c10 0000000000000000
 ffff8801c229c410 ffff8801c2057b00 ffff8801c229c300 ffff8801c2057b28
 ffffffff8165fb7a 0000000000002b25 ffff8801c2057a80 00000001d0d3a067
Call Trace:
 [<ffffffff81d922b9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d922b9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8165fb7a>] handle_userfault+0xa3a/0x1310 fs/userfaultfd.c:323
 [<ffffffff814cea81>] do_anonymous_page mm/memory.c:2747 [inline]
 [<ffffffff814cea81>] handle_pte_fault mm/memory.c:3488 [inline]
 [<ffffffff814cea81>] __handle_mm_fault mm/memory.c:3577 [inline]
 [<ffffffff814cea81>] handle_mm_fault+0x1fd1/0x2530 mm/memory.c:3614
 [<ffffffff810dd462>] __do_page_fault+0x5c2/0xd40 arch/x86/mm/fault.c:1406
 [<ffffffff810ddc07>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1469
 [<ffffffff838b0158>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1007
 [<ffffffff81615000>] ? SyS_utim