[v5.15] WARNING in md_alloc

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4878aadf2d15 Linux 5.15.161
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=159e3285980000
kernel config: https://syzkaller.appspot.com/x/.config?x=875d98826c53bf16
dashboard link: https://syzkaller.appspot.com/bug?extid=8ecba5ad1880c82079ac
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17106b12980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13bd4285980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f227a150ea92/disk-4878aadf.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6cfc50bf8b4e/vmlinux-4878aadf.xz
kernel image: https://storage.googleapis.com/syzbot-assets/23f7adc3c761/bzImage-4878aadf.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8ecba5...@syzkaller.appspotmail.com

RDX: 0000000000000000 RSI: 0000000020000a80 RDI: 00000000ffffff9c
RBP: 00007f41cdd733f0 R08: 00007f41cdc856c0 R09: 00007f41cdd733f8
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f41cdd733fc
R13: 000000000000006e R14: 00007fff2720bae0 R15: 00007fff2720bbc8
</TASK>
kobject_add_internal failed for md0 with -EEXIST, don't try to register things with the same name in the same directory.
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4162 at block/genhd.c:549 device_add_disk+0x786/0xd60 block/genhd.c:547
Modules linked in:
CPU: 0 PID: 4162 Comm: syz-executor178 Not tainted 5.15.161-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:device_add_disk+0x786/0xd60 block/genhd.c:549
Code: 4c 89 e0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 c6 04 00 00 41 8b 34 24 48 c7 c7 60 7b ef 8c e8 b1 a6 39 00 eb 05 e8 3a 4e 8e fd <0f> 0b bd 01 00 00 00 89 e8 48 83 c4 70 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc90004357618 EFLAGS: 00010293
RAX: ffffffff83f20c96 RBX: 0000000000000009 RCX: ffff88807d58bb80
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000103
RBP: dffffc0000000000 R08: ffffffff83f20c5b R09: ffffed100df7c188
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801cd62800
R13: ffff88806fbe0bc0 R14: 1ffff110039ac514 R15: 1ffff1100df7c187
FS: 00007f41cdc856c0(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f41cdc85d58 CR3: 0000000074f65000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
add_disk include/linux/genhd.h:203 [inline]
md_alloc+0x8ad/0xd40 drivers/md/md.c:5783
blk_request_module+0x181/0x1a0 block/genhd.c:687
blkdev_get_no_open+0x39/0x190 block/bdev.c:740
blkdev_get_by_dev+0x89/0xa50 block/bdev.c:804
blkdev_open+0x138/0x2d0 block/fops.c:463
do_dentry_open+0x807/0xfb0 fs/open.c:826
do_open fs/namei.c:3608 [inline]
path_openat+0x2705/0x2f20 fs/namei.c:3742
do_filp_open+0x21c/0x460 fs/namei.c:3769
do_sys_openat2+0x13b/0x500 fs/open.c:1253
do_sys_open fs/open.c:1269 [inline]
__do_sys_openat fs/open.c:1285 [inline]
__se_sys_openat fs/open.c:1280 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1280
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f41cdcea449
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 18 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f41cdc85168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f41cdd733f8 RCX: 00007f41cdcea449
RDX: 0000000000000000 RSI: 0000000020000a80 RDI: 00000000ffffff9c
RBP: 00007f41cdd733f0 R08: 00007f41cdc856c0 R09: 00007f41cdd733f8
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f41cdd733fc
R13: 000000000000006e R14: 00007fff2720bae0 R15: 00007fff2720bbc8
</TASK>


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