In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix WARNING in markbufferdirty due to discarded buffer reuse
A syzbot stress test using a corrupted disk image reported that markbufferdirty() called from _nilfsmarkinodedirty() or nilfspalloccommitallocentry() may output a kernel warning, and can panic if the kernel is booted with paniconwarn.
This is because nilfs2 keeps buffer pointers in local structures for some metadata and reuses them, but such buffers may be forcibly discarded by nilfscleardirty_page() in some critical situations.
This issue is reported to appear after commit 28a65b49eb53 ("nilfs2: do not write dirty data after degenerating to read-only"), but the issue has potentially existed before.
Fix this issue by checking the uptodate flag when attempting to reuse an internally held buffer, and reloading the metadata instead of reusing the buffer if the flag was lost.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/54xxx/CVE-2023-54140.json",
"cna_assigner": "Linux"
}