CVE-2026-31432

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.

• linux linux kernel (>= 5.15.145 < 5.16) • linux linux kernel (>= 6.1.71 < 6.2) • linux linux kernel (>= 6.6 < 6.12.81) • linux linux kernel (>= 6.13 < 6.18.22) • linux linux kernel (>= 6.19 < 6.19.12) • linux linux kernel 7.0