EXT4-fs error (device loop6): ext4_mb_generate_buddy:1126: group 0, block bitmap and bg descriptor inconsistent: 25 vs 4278190105 free clusters
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kernel BUG at fs/ext4/inode.c:2763!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 2937 Comm: syz.6.748 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ext4_writepages+0x30c2/0x30e0 fs/ext4/inode.c:2762
Code: 89 84 ff 84 db 75 31 e8 3c 86 84 ff 49 bc 00 00 00 00 00 fc ff df 4c 8b 7c 24 10 4c 8b 6c 24 40 e9 08 d3 ff ff e8 1e 86 84 ff <0f> 0b e8 17 86 84 ff e8 7e 87 13 ff eb 93 e8 0b 86 84 ff e8 72 87
RSP: 0018:ffffc9000270f1c0 EFLAGS: 00010283
RAX: ffffffff81ecf562 RBX: 0000009410000000 RCX: 0000000000080000
RDX: ffffc900016ba000 RSI: 0000000000001136 RDI: 0000000000001137
RBP: ffffc9000270f530 R08: ffff888139d23f3f R09: 1ffff110273a47e7
R10: dffffc0000000000 R11: ffffed10273a47e8 R12: dffffc0000000000
R13: ffff888117410000 R14: 0000008000000000 R15: 1ffff920004e1e64
FS:  00007f85561196c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6612179000 CR3: 0000000144fce000 CR4: 00000000003506b0
DR0: 0000000000000006 DR1: 0000000000000000 DR2: 000000007fffdff5
DR3: 0000800000000005 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_writepages+0x3a4/0x5f0 mm/page-writeback.c:2494
 filemap_fdatawrite_wbc+0x128/0x190 mm/filemap.c:408
 __filemap_fdatawrite_range mm/filemap.c:441 [inline]
 __filemap_fdatawrite mm/filemap.c:447 [inline]
 filemap_flush+0xe0/0x140 mm/filemap.c:474
 ext4_alloc_da_blocks+0x7a/0x190 fs/ext4/inode.c:3167
 ext4_rename fs/ext4/namei.c:3915 [inline]
 ext4_rename2+0xfb7/0x3180 fs/ext4/namei.c:4258
 vfs_rename+0xbd8/0x10f0 fs/namei.c:4881
 do_renameat2+0x826/0xfd0 fs/namei.c:5034
 __do_sys_rename fs/namei.c:5080 [inline]
 __se_sys_rename fs/namei.c:5078 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:5078
 x64_sys_call+0x300/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:83
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f855519ce59
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:00007f8556119028 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f8555415fa0 RCX: 00007f855519ce59
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000200000000280
RBP: 00007f8555232d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8555416038 R14: 00007f8555415fa0 R15: 00007ffe817c8128
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_writepages+0x30c2/0x30e0 fs/ext4/inode.c:2762
Code: 89 84 ff 84 db 75 31 e8 3c 86 84 ff 49 bc 00 00 00 00 00 fc ff df 4c 8b 7c 24 10 4c 8b 6c 24 40 e9 08 d3 ff ff e8 1e 86 84 ff <0f> 0b e8 17 86 84 ff e8 7e 87 13 ff eb 93 e8 0b 86 84 ff e8 72 87
RSP: 0018:ffffc9000270f1c0 EFLAGS: 00010283
RAX: ffffffff81ecf562 RBX: 0000009410000000 RCX: 0000000000080000
RDX: ffffc900016ba000 RSI: 0000000000001136 RDI: 0000000000001137
RBP: ffffc9000270f530 R08: ffff888139d23f3f R09: 1ffff110273a47e7
R10: dffffc0000000000 R11: ffffed10273a47e8 R12: dffffc0000000000
R13: ffff888117410000 R14: 0000008000000000 R15: 1ffff920004e1e64
FS:  00007f85561196c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556d9004e8 CR3: 0000000144fce000 CR4: 00000000003506b0
DR0: 0000000000000006 DR1: 0000000000000000 DR2: 000000007fffdff5
DR3: 0000800000000005 DR6: 00000000fffe0ff0 DR7: 0000000000000400