------------[ cut here ]------------
WARNING: CPU: 1 PID: 7442 at block/genhd.c:719 __device_add_disk.cold+0x69/0x188 block/genhd.c:719
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 7442 Comm: syz-executor.4 Not tainted 4.19.196-syzkaller #0
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+0x1fc/0x2ef lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 __warn.cold+0x20/0x5a kernel/panic.c:541
 report_bug+0x262/0x2b0 lib/bug.c:183
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:__device_add_disk.cold+0x69/0x188 block/genhd.c:719
Code: 02 84 c0 74 08 3c 03 0f 8e a8 00 00 00 44 8b a5 b8 05 00 00 e9 ad 75 6b fb e8 eb 17 67 f9 48 c7 c7 a0 70 b2 88 e8 c5 74 f7 ff <0f> 0b e9 d5 81 6b fb e8 d3 17 67 f9 48 c7 c7 a0 70 b2 88 e8 ad 74
RSP: 0018:ffff88804d7ffb38 EFLAGS: 00010286
RAX: 0000000000000024 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff814dfc91 RDI: ffffed1009afff59
RBP: ffff8880a951a400 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff8880a951a490
R13: ffff8880a951aa58 R14: 00000000fffffff4 R15: ffff8880a951a404
 add_disk include/linux/genhd.h:409 [inline]
 loop_add+0x628/0x8a0 drivers/block/loop.c:2048
 loop_control_ioctl drivers/block/loop.c:2149 [inline]
 loop_control_ioctl+0x16c/0x480 drivers/block/loop.c:2131
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe97e2e5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000003
RBP: 00007fe97e2e51d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffe110538bf R14: 00007fe97e2e5300 R15: 0000000000022000
Kernel Offset: disabled
Rebooting in 86400 seconds..