CVE-2026-98709wifi: mac80211: count only matching reservations in reserved switch

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: count only matching reservations in reserved switch ieee80211_vif_use_reserved_switch() validates a replacement by counting assigned links on ctx->replace_ctx and treating reservations too broadly. A link can still be assigned to the old channel context while holding a reservation that belongs to a different replacement operation. That can make the current replacement appear complete too early. If another link finalizes first, the function can free the WILL_BE_REPLACED chanctx while the unmatched link and driver still use it, leading to a use-after-free in later beacon generation. Require an in-place reservation to point at the current replacement context, and require the reserved and assigned contexts to be the matching replacement pair, before counting or moving the link.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/4c4671a706d2d85442a30850abfada5377ffbbc8
• https://git.kernel.org/stable/c/183cc72ae9467717afba8b8d194a558a6666cb53
• https://git.kernel.org/stable/c/b3d9f582f98e06070d5233b177b2899b693a01ec
• https://git.kernel.org/stable/c/4ae6ed5b6074df5f3da05fd74c40bb24c5c9b41d
• https://git.kernel.org/stable/c/d31f655e44631891788ca67018ec5e1ed1c7de86
• https://git.kernel.org/stable/c/03525b632908b049f4d04cc8a71cdff2329589cf
• https://git.kernel.org/stable/c/5cc54a000960bc88f8c58940164dca0e601ab39c
• https://git.kernel.org/stable/c/437f3727b4fd715266c296435c116288f82666fd