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: 14863 Comm: syz-executor4 Not tainted 4.18.0-next-20180824+ #47
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:loop_validate_file+0x247/0x470 drivers/block/loop.c:664
Code: 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 2e 02 00 00 4d 8b a4 24 f0 00 00 00 49 8d bc 24 b8 01 00 00 48 89 f8 48 c1 e8 03 <80> 3c 18 00 0f 85 03 02 00 00 4d 8b a4 24 b8 01 00 00 4c 89 e0 48
RSP: 0018:ffff8801c06978f8 EFLAGS: 00010202
RAX: 0000000000000037 RBX: dffffc0000000000 RCX: ffffffff83de7ef9
RDX: 0000000000000000 RSI: ffffffff83de7f07 RDI: 00000000000001b8
RBP: ffff8801c0697918 R08: ffff8801c56d8240 R09: ffffed003b6046de
R10: 0000000000000003 R11: 0000000000000001 R12: 0000000000000000
R13: ffff8801c93793c0 R14: 0000000000000002 R15: ffff8801c93793c0
FS:  0000000002106940(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200000c0 CR3: 00000001c341b000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 loop_change_fd drivers/block/loop.c:709 [inline]
 lo_ioctl+0x9e0/0x1d70 drivers/block/loop.c:1412
 __blkdev_driver_ioctl block/ioctl.c:303 [inline]
 blkdev_ioctl+0x9cd/0x2030 block/ioctl.c:601
 block_ioctl+0xee/0x130 fs/block_dev.c:1883
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
 __do_sys_ioctl fs/ioctl.c:709 [inline]
 __se_sys_ioctl fs/ioctl.c:707 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
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:00007ffebb4972d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000002106914 RCX: 0000000000457089
RDX: 0000000000000004 RSI: 0000000000004c06 RDI: 0000000000000005
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cf2b0 R14: 00000000004c587a R15: 0000000000000000
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace cfdfc883aab76b04 ]---
RIP: 0010:loop_validate_file+0x247/0x470 drivers/block/loop.c:664
Code: 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 2e 02 00 00 4d 8b a4 24 f0 00 00 00 49 8d bc 24 b8 01 00 00 48 89 f8 48 c1 e8 03 <80> 3c 18 00 0f 85 03 02 00 00 4d 8b a4 24 b8 01 00 00 4c 89 e0 48
RSP: 0018:ffff8801c06978f8 EFLAGS: 00010202
RAX: 0000000000000037 RBX: dffffc0000000000 RCX: ffffffff83de7ef9
RDX: 0000000000000000 RSI: ffffffff83de7f07 RDI: 00000000000001b8
RBP: ffff8801c0697918 R08: ffff8801c56d8240 R09: ffffed003b6046de
R10: 0000000000000003 R11: 0000000000000001 R12: 0000000000000000
R13: ffff8801c93793c0 R14: 0000000000000002 R15: ffff8801c93793c0
FS:  0000000002106940(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200000c0 CR3: 00000001c341b000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400