EXT4-fs error (device loop6): ext4_mb_generate_buddy:1113: group 0, block bitmap and bg descriptor inconsistent: 0 vs 150994969 free clusters
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kernel BUG at fs/ext4/inode.c:2761!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1149 Comm: syz.6.218 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ext4_writepages+0x30c2/0x30e0 fs/ext4/inode.c:2760
Code: 11 85 ff 84 db 75 31 e8 ac 0e 85 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 8e 0e 85 ff <0f> 0b e8 87 0e 85 ff e8 6e 1e 14 ff eb 93 e8 7b 0e 85 ff e8 62 1e
RSP: 0018:ffffc90000ca7800 EFLAGS: 00010287
RAX: ffffffff81ec5e72 RBX: 0000008410000000 RCX: 0000000000080000
RDX: ffffc900021ed000 RSI: 0000000000000023 RDI: 0000000000000024
RBP: ffffc90000ca7b70 R08: ffff888136e94aaf R09: 1ffff11026dd2955
R10: dffffc0000000000 R11: ffffed1026dd2956 R12: dffffc0000000000
R13: ffff8881413ba000 R14: 0000008000000000 R15: 1ffff92000194f2c
FS:  00007fe7738e56c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d210ff8 CR3: 000000011a2f4000 CR4: 00000000003526b0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 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]
 file_write_and_wait_range+0x159/0x230 mm/filemap.c:794
 ext4_sync_file+0x1a9/0xa10 fs/ext4/fsync.c:151
 vfs_fsync_range fs/sync.c:188 [inline]
 vfs_fsync fs/sync.c:202 [inline]
 do_fsync fs/sync.c:212 [inline]
 __do_sys_fdatasync fs/sync.c:226 [inline]
 __se_sys_fdatasync fs/sync.c:224 [inline]
 __x64_sys_fdatasync+0xc6/0x140 fs/sync.c:224
 x64_sys_call+0x11d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:76
 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: 0033:0x7fe77299c799
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:00007fe7738e5028 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: ffffffffffffffda RBX: 00007fe772c15fa0 RCX: 00007fe77299c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007fe772a32bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe772c16038 R14: 00007fe772c15fa0 R15: 00007ffcac42a738
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_writepages+0x30c2/0x30e0 fs/ext4/inode.c:2760
Code: 11 85 ff 84 db 75 31 e8 ac 0e 85 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 8e 0e 85 ff <0f> 0b e8 87 0e 85 ff e8 6e 1e 14 ff eb 93 e8 7b 0e 85 ff e8 62 1e
RSP: 0018:ffffc90000ca7800 EFLAGS: 00010287
RAX: ffffffff81ec5e72 RBX: 0000008410000000 RCX: 0000000000080000
RDX: ffffc900021ed000 RSI: 0000000000000023 RDI: 0000000000000024
RBP: ffffc90000ca7b70 R08: ffff888136e94aaf R09: 1ffff11026dd2955
R10: dffffc0000000000 R11: ffffed1026dd2956 R12: dffffc0000000000
R13: ffff8881413ba000 R14: 0000008000000000 R15: 1ffff92000194f2c
FS:  00007fe7738e56c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d20bff8 CR3: 000000011a2f4000 CR4: 00000000003526a0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000fffe0ff0 DR7: 0000000000000400