[v5.15] WARNING in setup_conf

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 792fbe1537d8 Linux 5.15.223
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=159a5481580000
kernel config: https://syzkaller.appspot.com/x/.config?x=24e573deff4d39b7
dashboard link: https://syzkaller.appspot.com/bug?extid=9b1c69e01fe629f84d95
compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ac7c54df9a60/disk-792fbe15.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d6a042e367f4/vmlinux-792fbe15.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a3fa0a6dba38/bzImage-792fbe15.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9b1c69...@syzkaller.appspotmail.com

md: array md2 already initialised!
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7843 at mm/page_alloc.c:5476 current_gfp_context include/linux/sched/mm.h:-1 [inline]
WARNING: CPU: 0 PID: 7843 at mm/page_alloc.c:5476 __alloc_pages+0x39f/0x480 mm/page_alloc.c:5488
Modules linked in:
CPU: 1 PID: 7843 Comm: syz.2.1085 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:__alloc_pages+0x39f/0x480 mm/page_alloc.c:5476
Code: 31 ff e9 b1 fe ff ff e8 8f 82 0d 08 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c 4f fd ff ff 4c 89 e7 e8 06 d4 09 00 e9 42 fd ff ff <0f> 0b 45 31 ff e9 ee fe ff ff 65 44 8b 2d f7 80 4d 7e 41 83 fd 08
RSP: 0018:ffffc9000310f460 EFLAGS: 00010246
RAX: ffffc9000310f4a0 RBX: 1ffff92000621e90 RCX: 0000000000000000
RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc9000310f4c8
RBP: ffffc9000310f558 R08: ffffc9000310f4c7 R09: ffffc9000310f4a0
R10: dffffc0000000000 R11: fffff52000621e99 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000040dc0 R15: 000000000000000d
FS: 00007f31fa2256c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005627f87bf660 CR3: 000000004374b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
kmalloc_order+0x40/0x150 mm/slab_common.c:986
kmalloc_order_trace+0x14/0xf0 mm/slab_common.c:1002
kmalloc_array include/linux/slab.h:647 [inline]
kcalloc include/linux/slab.h:676 [inline]
setup_conf+0xc8f/0x2b60 drivers/md/raid5.c:7286
raid5_run+0x90b/0x28c0 drivers/md/raid5.c:7623
md_run+0xebf/0x2230 drivers/md/md.c:6014
do_md_run+0x30/0x400 drivers/md/md.c:6139
md_ioctl+0x2312/0x26f0 drivers/md/md.c:7793
blkdev_ioctl+0x347/0x6f0 block/ioctl.c:604
block_ioctl+0xac/0xf0 block/fops.c:496
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f31fbfce559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f31fa225028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f31fc254fa0 RCX: 00007f31fbfce559
RDX: 0000200000000700 RSI: 00000000400c0930 RDI: 0000000000000003
RBP: 00007f31fc065b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f31fc255038 R14: 00007f31fc254fa0 R15: 00007fffa28b5c98
</TASK>


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