kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 1 PID: 25034 Comm: syz-executor7 Not tainted 4.18.0-rc7-next-20180803+ #31
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:do_remount_sb+0x371/0x850 fs/super.c:984
Code: ff ff ff e8 31 e1 19 05 41 89 c5 48 8b 85 30 ff ff ff 48 8d b8 e0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e b5 03 00 00 48 8b 85 30 ff ff
RSP: 0018:ffff8801b110fa38 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801d474e880 RCX: ffffc90002e54000
RDX: 000000000000001c RSI: ffffffff81eecdef RDI: 00000000000000e0
RBP: ffff8801b110fb40 R08: ffff8801cf4c2000 R09: fffffbfff0fc24e5
R10: fffffbfff0fc24e5 R11: ffffffff87e1272b R12: ffff8801b110fb18
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  00007fcec9be2700(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdd73cdd248 CR3: 00000001b3b25000 CR4: 00000000001406e0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 do_umount fs/namespace.c:1464 [inline]
 ksys_umount+0xfbf/0x1310 fs/namespace.c:1582
 __do_sys_umount fs/namespace.c:1593 [inline]
 __se_sys_umount fs/namespace.c:1591 [inline]
 __x64_sys_umount+0x54/0x80 fs/namespace.c:1591
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456cb9
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:00007fcec9be1c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007fcec9be26d4 RCX: 0000000000456cb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d6360 R14: 00000000004c9ab8 R15: 0000000000000000
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace a936fdbcbcbd929d ]---
RIP: 0010:do_remount_sb+0x371/0x850 fs/super.c:984
Code: ff ff ff e8 31 e1 19 05 41 89 c5 48 8b 85 30 ff ff ff 48 8d b8 e0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e b5 03 00 00 48 8b 85 30 ff ff
RSP: 0018:ffff8801b110fa38 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801d474e880 RCX: ffffc90002e54000
RDX: 000000000000001c RSI: ffffffff81eecdef RDI: 00000000000000e0
RBP: ffff8801b110fb40 R08: ffff8801cf4c2000 R09: fffffbfff0fc24e5
R10: fffffbfff0fc24e5 R11: ffffffff87e1272b R12: ffff8801b110fb18
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  00007fcec9be2700(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdd73cdd248 CR3: 00000001b3b25000 CR4: 00000000001406e0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600