RAX: ffffffffffffffda RBX: 00007f420d4786d4 RCX: 0000000000455a79
RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016
R13: 00000000004bdfb1 R14: 00000000004ccab0 R15: 000000000000002d
WARNING: CPU: 1 PID: 7190 at block/genhd.c:697 __device_add_disk+0x106a/0x1360 block/genhd.c:697
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 7190 Comm: syz-executor0 Not tainted 4.18.0-rc4+ #144
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 panic+0x238/0x4e7 kernel/panic.c:184
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:__device_add_disk+0x106a/0x1360 block/genhd.c:697
Code: ff ff 48 89 df e8 a6 d3 6a fe e9 c9 f0 ff ff e8 1c d4 6a fe e9 83 f4 ff ff e8 42 f9 2c fe 0f 0b e9 52 fb ff ff e8 36 f9 2c fe <0f> 0b e9 cb fe ff ff 4c 89 f7 e8 f7 d3 6a fe e9 0c f1 ff ff e8 2d 
RSP: 0018:ffff88018727f888 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff8801cdbd3680 RCX: ffffc90001e1c000
RDX: 0000000000040000 RSI: ffffffff834f126a RDI: 0000000000000005
RBP: ffff88018727fa58 R08: ffff88019bb2a580 R09: ffffed003b5e46d6
R10: ffffed003b5e46d6 R11: ffff8801daf236b3 R12: 00000000fffffff4
R13: ffff88018727fa30 R14: ffff8801cdbd3be0 R15: ffff8801cdbd3684
 device_add_disk+0x22/0x30 block/genhd.c:717
 add_disk include/linux/genhd.h:399 [inline]
 loop_add+0x71d/0x9d0 drivers/block/loop.c:1910
 loop_control_ioctl+0x199/0x540 drivers/block/loop.c:2007
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455a79
Code: 1d ba 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007f420d477c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f420d4786d4 RCX: 0000000000455a79
RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016
R13: 00000000004bdfb1 R14: 00000000004ccab0 R15: 000000000000002d
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..