kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 24980 Comm: syz-executor0 Not tainted 4.9.135+ #13
task: ffff8801ac500000 task.stack: ffff8801a3a00000
RIP: 0010:[<ffffffff81dd48f8>]  [<ffffffff81dd48f8>] is_loop_device drivers/block/loop.c:645 [inline]
RIP: 0010:[<ffffffff81dd48f8>]  [<ffffffff81dd48f8>] loop_validate_file+0x208/0x400 drivers/block/loop.c:656
RSP: 0018:ffff8801a3a07c88  EFLAGS: 00010206
RAX: 0000000000000036 RBX: dffffc0000000000 RCX: ffffc90000927000
RDX: 0000000000000096 RSI: ffffffff81dd48c8 RDI: 00000000000001b0
RBP: ffff8801a3a07ca0 R08: ffff8801ac5008b0 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: ffff8801d477bf40 R14: ffff8801d477bf40 R15: ffff8801ce675c58
FS:  0000000000000000(0000) GS:ffff8801db600000(0063) knlGS:00000000f5782b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00007f777bb43169 CR3: 00000001d8466000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801ce675b00 ffff8801d4959600 0000000000000003 ffff8801a3a07d28
 ffffffff81ddb61f ffff88021fffd057 ffff8801cfd21d70 0000000000000001
 ffff8801cfc80000 ffff8801ce675b18 a49769fde2c330c9 1ffff10034740fa8
Call Trace:
 [<ffffffff81ddb61f>] loop_change_fd drivers/block/loop.c:702 [inline]
 [<ffffffff81ddb61f>] lo_ioctl+0x45f/0x1910 drivers/block/loop.c:1378
 [<ffffffff81ddcb7c>] lo_compat_ioctl+0xac/0x140 drivers/block/loop.c:1574
 [<ffffffff81b30064>] compat_blkdev_ioctl+0x3a4/0x3630 block/compat_ioctl.c:751
 [<ffffffff81619c1d>] C_SYSC_ioctl fs/compat_ioctl.c:1602 [inline]
 [<ffffffff81619c1d>] compat_SyS_ioctl+0x12d/0x1fd0 fs/compat_ioctl.c:1549
 [<ffffffff81006311>] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline]
 [<ffffffff81006311>] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
 [<ffffffff82804960>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
Code: 00 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 f7 01 00 00 4d 8b a4 24 f0 00 00 00 49 8d bc 24 b0 01 00 00 48 89 f8 48 c1 e8 03 <80> 3c 18 00 0f 85 cc 01 00 00 4d 8b a4 24 b0 01 00 00 4c 89 e0 
RIP  [<ffffffff81dd48f8>] is_loop_device drivers/block/loop.c:645 [inline]
RIP  [<ffffffff81dd48f8>] loop_validate_file+0x208/0x400 drivers/block/loop.c:656
 RSP <ffff8801a3a07c88>
---[ end trace 8735ed0b3d0df9c7 ]---