CVE-2026-31432
Description
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 smb2_get_info_sec() checked buffer space using ppntsd_size from xattr, while build_sec_desc() often synthesized a significantly larger descriptor from POSIX ACLs. This patch introduces smb_acl_sec_desc_scratch_len() to accurately compute the final descriptor size beforehand, performs proper buffer checking with smb2_calc_max_out_buf_len(), and uses exact-sized allocation + iov pinning.
How to fix
- linux linux_kernel5.16, 6.2, 6.12.81, 6.18.22, 6.19.12 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 5.15.145 ≤ v < 5.16, 6.1.71 ≤ v < 6.2, 6.6 ≤ v < 6.12.81, 6.13 ≤ v < 6.18.22, 6.19 ≤ v < 6.19.12, 7.0 | 5.16, 6.2, 6.12.81, 6.18.22, 6.19.12 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.