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.
