print_req_error: I/O error, dev loop4, sector 128
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: 0 PID: 21102 Comm: syz-executor6 Not tainted 4.18.0-rc2+ #120
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:open_fs_devices+0x7f0/0xc80 fs/btrfs/volumes.c:1124
Code: 48 8b 85 e0 fe ff ff 41 c7 87 14 01 00 00 01 00 00 00 48 8d b8 a0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ab 03 00 00 48 8b 85 e0 fe ff ff 49 8d 7f 50 48 
RSP: 0018:ffff88019feef1d8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc9000c668000
RDX: 0000000000000014 RSI: ffffffff82caed45 RDI: 00000000000000a0
RBP: ffff88019feef348 R08: ffff8801d80be1c0 R09: ffffed003670fb30
R10: ffffed003670fb30 R11: ffff8801b387d983 R12: ffff8801d4850618
R13: ffff88019feef2a0 R14: dffffc0000000000 R15: ffff8801d4850540
FS:  00007f828377b700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30521000 CR3: 00000001c7b4e000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 btrfs_open_devices+0xc0/0xd0 fs/btrfs/volumes.c:1155
 btrfs_mount_root+0x942/0x1e90 fs/btrfs/super.c:1568
 mount_fs+0xae/0x328 fs/super.c:1277
 vfs_kern_mount.part.34+0xdc/0x4e0 fs/namespace.c:1037
 vfs_kern_mount+0x40/0x60 fs/namespace.c:1027
 btrfs_mount+0x4a9/0x215e fs/btrfs/super.c:1661
 mount_fs+0xae/0x328 fs/super.c:1277
 vfs_kern_mount.part.34+0xdc/0x4e0 fs/namespace.c:1037
 vfs_kern_mount fs/namespace.c:1027 [inline]
 do_new_mount fs/namespace.c:2518 [inline]
 do_mount+0x581/0x30e0 fs/namespace.c:2848
 ksys_mount+0x12d/0x140 fs/namespace.c:3064
 __do_sys_mount fs/namespace.c:3078 [inline]
 __se_sys_mount fs/namespace.c:3075 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4584ca
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 dd 8f fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ba 8f fb ff c3 66 0f 1f 84 00 00 00 00 00 
RSP: 002b:00007f828377aa88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f828377ab30 RCX: 00000000004584ca
RDX: 00007f828377aad0 RSI: 0000000020000100 RDI: 00007f828377aaf0
RBP: 0000000020000100 R08: 00007f828377ab30 R09: 00007f828377aad0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000014
R13: 0000000000000000 R14: 00000000004d3218 R15: 0000000000000000
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace 4069c74488b41432 ]---
RIP: 0010:open_fs_devices+0x7f0/0xc80 fs/btrfs/volumes.c:1124
Code: 48 8b 85 e0 fe ff ff 41 c7 87 14 01 00 00 01 00 00 00 48 8d b8 a0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ab 03 00 00 48 8b 85 e0 fe ff ff 49 8d 7f 50 48 
RSP: 0018:ffff88019feef1d8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc9000c668000
RDX: 0000000000000014 RSI: ffffffff82caed45 RDI: 00000000000000a0
RBP: ffff88019feef348 R08: ffff8801d80be1c0 R09: ffffed003670fb30
R10: ffffed003670fb30 R11: ffff8801b387d983 R12: ffff8801d4850618
R13: ffff88019feef2a0 R14: dffffc0000000000 R15: ffff8801d4850540
FS:  00007f828377b700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30521000 CR3: 00000001c7b4e000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400