wifi: mac80211: count only matching reservations in reserved switch

Summary

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.

Timeline

1. Oct 18, 2026, 3:46 PM UTCCVE published
2. Oct 21, 2026, 12:55 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 5bcae31d9cb1ebfad3ad5a3eea04c8cdc329a04f · fixed in 4ae6ed5b6074df5f3da05fd74c40bb24c5c9b41d; From 5bcae31d9cb1ebfad3ad5a3eea04c8cdc329a04f · fixed in d31f655e44631891788ca67018ec5e1ed1c7de86; From 5bcae31d9cb1ebfad3ad5a3eea04c8cdc329a04f · fixed in 03525b632908b049f4d04cc8a71cdff2329589cf; From 5bcae31d9cb1ebfad3ad5a3eea04c8cdc329a04f · fixed in 5cc54a000960bc88f8c58940164dca0e601ab39c; From 5bcae31d9cb1ebfad3ad5a3eea04c8cdc329a04f · fixed in 437f3727b4fd715266c296435c116288f82666fd

• Linux Linux

  3.17

• KernelLinux

  From 3.17.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.113; From 6.13.0 · fixed in 6.18.56; From 6.19.0 · fixed in 7.2.10

References 5