EXT4-fs error (device loop5): 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: 1 PID: 6489 Comm: syz.5.1307 Tainted: G        W          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: 1d 85 ff 84 db 75 31 e8 bc 1a 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 9e 1a 85 ff <0f> 0b e8 97 1a 85 ff e8 6e 2b 14 ff eb 93 e8 8b 1a 85 ff e8 62 2b
RSP: 0018:ffffc90000d771c0 EFLAGS: 00010293
RAX: ffffffff81ec5172 RBX: 0000009410000000 RCX: ffff8881113c5100
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc90000d77530 R08: ffff888133ee285f R09: 1ffff110267dc50b
R10: dffffc0000000000 R11: ffffed10267dc50c R12: dffffc0000000000
R13: ffff88811b0dc000 R14: 0000008000000000 R15: 1ffff920001aee64
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563ebac0c300 CR3: 0000000117b2e000 CR4: 00000000003526a0
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:3165
 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+0x210/0x2d0 kernel/exit.c:1028
 get_signal+0x13b5/0x1520 kernel/signal.c:2891
 arch_do_signal_or_restart+0xd1/0x1140 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3b50d9c629
Code: Unable to access opcode bytes at 0x7f3b50d9c5ff.
RSP: 002b:00007f3b51c070e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f3b51015fa8 RCX: 00007f3b50d9c629
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3b51015fa8
RBP: 00007f3b51015fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3b51016038 R14: 00007fffe4389ef0 R15: 00007fffe4389fd8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_writepages+0x30c2/0x30e0 fs/ext4/inode.c:2760
Code: 1d 85 ff 84 db 75 31 e8 bc 1a 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 9e 1a 85 ff <0f> 0b e8 97 1a 85 ff e8 6e 2b 14 ff eb 93 e8 8b 1a 85 ff e8 62 2b
RSP: 0018:ffffc90000d771c0 EFLAGS: 00010293
RAX: ffffffff81ec5172 RBX: 0000009410000000 RCX: ffff8881113c5100
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc90000d77530 R08: ffff888133ee285f R09: 1ffff110267dc50b
R10: dffffc0000000000 R11: ffffed10267dc50c R12: dffffc0000000000
R13: ffff88811b0dc000 R14: 0000008000000000 R15: 1ffff920001aee64
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563ebac22da8 CR3: 0000000109618000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400