EXT4-fs error (device loop4): 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: 515 Comm: syz.4.49 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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 85 13 ff eb 93 e8 0b 86 84 ff e8 72 85
RSP: 0018:ffffc9000faef500 EFLAGS: 00010293
RAX: ffffffff81ecf762 RBX: 0000009410000000 RCX: ffff888115261440
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc9000faef870 R08: ffff888132e2caaf R09: 1ffff110265c5955
R10: dffffc0000000000 R11: ffffed10265c5956 R12: dffffc0000000000
R13: ffff88811c6f0000 R14: 0000008000000000 R15: 1ffff92001f5decc
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c30611d CR3: 000000011033a000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 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_release_file+0x84/0x320 fs/ext4/file.c:158
 __fput+0x1fc/0x8f0 fs/file_table.c:320
 ____fput+0x15/0x20 fs/file_table.c:348
 task_work_run+0x1e1/0x250 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0xa35/0x2660 kernel/exit.c:886
 do_group_exit+0x225/0x2e0 kernel/exit.c:1029
 __do_sys_exit_group kernel/exit.c:1040 [inline]
 __se_sys_exit_group kernel/exit.c:1038 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1038
 x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
 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: 0033:0x7f67a059ce59
Code: Unable to access opcode bytes at 0x7f67a059ce2f.
RSP: 002b:00007ffcc35f6318 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f67a059ce59
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffcc35f637c R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000008
R13: 00000000000927c0 R14: 00000000000098b3 R15: 00007ffcc35f63d0
 </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 85 13 ff eb 93 e8 0b 86 84 ff e8 72 85
RSP: 0018:ffffc9000faef500 EFLAGS: 00010293
RAX: ffffffff81ecf762 RBX: 0000009410000000 RCX: ffff888115261440
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc9000faef870 R08: ffff888132e2caaf R09: 1ffff110265c5955
R10: dffffc0000000000 R11: ffffed10265c5956 R12: dffffc0000000000
R13: ffff88811c6f0000 R14: 0000008000000000 R15: 1ffff92001f5decc
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd72e5ea540 CR3: 000000011033a000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400