[v6.1] WARNING in ext4_discard_allocated_blocks

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 420102835862 Linux 6.1.134
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10a1c63f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=5b8d7e66d7963efe
dashboard link: https://syzkaller.appspot.com/bug?extid=ca8872a4fda81c1c8f4c
compiler: Debian clang version 15.0.6, Debian LLD 15.0.6
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14cf3fe4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/91a5e36a108f/disk-42010283.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ec90f2faa77e/vmlinux-42010283.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dce3af94d7be/bzImage-42010283.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/046ee083ea25/mount_0.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=14f7eccc580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ca8872...@syzkaller.appspotmail.com

------------[ cut here ]------------
mb_load_buddy failed (-117)
WARNING: CPU: 1 PID: 5957 at fs/ext4/mballoc.c:4313 ext4_discard_allocated_blocks+0x199/0x6d0 fs/ext4/mballoc.c:4313
Modules linked in:
CPU: 1 PID: 5957 Comm: syz.0.99 Not tainted 6.1.134-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:ext4_discard_allocated_blocks+0x199/0x6d0 fs/ext4/mballoc.c:4313
Code: 0c 00 00 e8 39 27 ff ff 89 c3 31 ff 89 c6 e8 9e a3 4c ff 85 db 74 67 e8 35 a0 4c ff 48 c7 c7 80 9a 1f 8b 89 de e8 c7 e2 14 ff <0f> 0b e9 76 03 00 00 e8 1b a0 4c ff 49 83 c7 3c 4c 89 f8 48 c1 e8
RSP: 0018:ffffc900058ced20 EFLAGS: 00010246
RAX: edda4fb02316a300 RBX: 00000000ffffff8b RCX: ffff88802d4d8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900058cee50 R08: ffffffff815291ce R09: ffffed10171e4f1c
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000b19db0
R13: dffffc0000000000 R14: ffff8880745d75c4 R15: ffff8880745d7578
FS: 00007ff05f4996c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2284bffffc CR3: 000000005954d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_mb_new_blocks+0x154e/0x4b80 fs/ext4/mballoc.c:-1
ext4_ext_map_blocks+0x1c1c/0x7ab0 fs/ext4/extents.c:4339
ext4_map_blocks+0xa2b/0x1cb0 fs/ext4/inode.c:678
_ext4_get_block+0x23b/0x660 fs/ext4/inode.c:821
ext4_block_write_begin+0x631/0x1400 fs/ext4/inode.c:1123
ext4_write_begin+0x638/0xf80 fs/ext4/ext4_jbd2.h:-1
ext4_da_write_begin+0x30a/0x9c0 fs/ext4/inode.c:2999
generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845
ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:285
ext4_file_write_iter+0x1d7/0x1930 fs/ext4/file.c:-1
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x857/0xbc0 fs/read_write.c:584
ksys_write+0x19c/0x2c0 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff05e58e169
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff05f499038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff05e7b5fa0 RCX: 00007ff05e58e169
RDX: 000000000000a000 RSI: 0000200000000780 RDI: 0000000000000005
RBP: 00007ff05e610a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff05e7b5fa0 R15: 00007ffc9ee22158
</TASK>


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