BUG: unable to handle kernel NULL pointer dereference at 00000000000000f0
PGD 800000013aa0f067 P4D 800000013aa0f067 PUD 1c70f2067 PMD 0 
Oops: 0000 [#1] SMP PTI
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 6763 Comm: syz-executor1 Not tainted 4.17.0+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:is_loop_device drivers/block/loop.c:711 [inline]
RIP: 0010:loop_set_fd drivers/block/loop.c:901 [inline]
RIP: 0010:lo_ioctl+0x10e0/0x4450 drivers/block/loop.c:1398
RSP: 0018:ffff8801394ef870 EFLAGS: 00010246
RAX: ffff8801d37b3ef0 RBX: 00000000000000f0 RCX: ffff880000000000
RDX: ffff8801d37b5ef0 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff8801394efb00 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000000 R11: ffffffff861c5f10 R12: 0000000000000000
R13: 000000000802001d R14: ffff8801d37b1ef0 R15: 0000000000000000
FS:  00007fdf58889700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000f0 CR3: 00000001395f6000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __blkdev_driver_ioctl block/ioctl.c:303 [inline]
 blkdev_ioctl+0x2290/0x4f80 block/ioctl.c:601
 block_ioctl+0x16f/0x1d0 fs/block_dev.c:1877
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0xcbd/0x24b0 fs/ioctl.c:686
 ksys_ioctl fs/ioctl.c:701 [inline]
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x280/0x320 fs/ioctl.c:706
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4559f9
RSP: 002b:00007fdf58888c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdf588896d4 RCX: 00000000004559f9
RDX: 0000000000000014 RSI: 0000000000004c00 RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004bdedc R14: 00000000004cbcf8 R15: 0000000000000000
Code: 00 4d 85 e4 0f 85 15 01 00 00 49 8b 1e b8 f0 00 00 00 48 01 c3 4c 89 f7 e8 be 15 a4 fb 48 83 38 00 44 8b 6d 90 0f 85 01 01 00 00 <4c> 8b 3b 48 89 df e8 a5 15 a4 fb 48 83 38 00 0f 85 f8 00 00 00 
RIP: is_loop_device drivers/block/loop.c:711 [inline] RSP: ffff8801394ef870
RIP: loop_set_fd drivers/block/loop.c:901 [inline] RSP: ffff8801394ef870
RIP: lo_ioctl+0x10e0/0x4450 drivers/block/loop.c:1398 RSP: ffff8801394ef870
CR2: 00000000000000f0
---[ end trace 46005952ca5dfbac ]---