In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix OOB write in QUERY_INFO for compound requests
When a compound request such as READ + QUERY_INFO(Security) is received, and the first command (READ) consumes most of the response buffer, ksmbd could write beyond the allocated buffer while building a security descriptor.
The root cause was that smb2getinfosec() checked buffer space using ppntsdsize from xattr, while buildsecdesc() often synthesized a significantly larger descriptor from POSIX ACLs.
This patch introduces smbaclsecdescscratchlen() to accurately compute the final descriptor size beforehand, performs proper buffer checking with smb2calcmaxoutbuflen(), and uses exact-sized allocation + iov pinning.
{
"cna_assigner": "Linux",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31432.json"
}