UBUNTU-CVE-2026-64445: High severity ubuntu/linux-azure vulnerability

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix WEP length underflow and OOB read in OnAuth() OnAuth() has two bugs in the shared-key authentication path. When the Privacy bit is set, rtwwepdecrypt() is called without verifying that the frame is long enough to contain a valid WEP IV and ICV. Inside rtwwepdecrypt(), length is computed as: length = len - WLANHDRA3LEN - ivlen and then passed as (length - 4) to crc32le(). If len is less than WLANHDRA3LEN + ivlen + icvlen (32 bytes), length - 4 is negative and, after the implicit cast to sizet, causes crc32le() to read far beyond the frame buffer. Add a minimum length check before accessing the IV field and calling the decryption path. When processing a seq=3 response, rtwgetie() stores the Challenge Text IE length in ielen, but the subsequent memcmp() always reads 128 bytes regardless of ielen. IEEE 802.11 mandates a challenge text of exactly 128 bytes; reject any IE whose length field differs, matching the check already applied to OnAuthClient().