CVE-2026-64223wifi: mac80211: consume only present negotiated TTLM maps

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: consume only present negotiated TTLM maps ieee80211_tid_to_link_map_size_ok() validates negotiated TTLM elements against the number of link-map entries indicated by link_map_presence. ieee80211_parse_neg_ttlm() must consume the same layout. The parser advanced its cursor for every TID, including TIDs whose presence bit is clear and therefore have no map bytes in the element. A sparse map can then make a later present TID read past the validated element. The bad bytes land in neg_ttlm->{up,down}link[tid] but are gated by valid_links before being applied to driver state, so a peer cannot turn the read into a policy change. Under KUnit + KASAN with an exact-sized element allocation the OOB read is reported as a slab-out-of-bounds; whether the same trigger fires under the production RX path depends on surrounding allocator state. Advance the cursor only when the current TID has a map present.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/f7d395dc5008168ac5b9c1ac2791e59a6078cca1
• https://git.kernel.org/stable/c/2dd9304727c7041df0a599595910bdbe02ad03c5
• https://git.kernel.org/stable/c/2becaaeebe230ade1fcd5d0f1cde4d6ee93ec78f
• https://git.kernel.org/stable/c/a6e6ccd5bd07155c2add6c74ce1a5e68ad3b95ea