CVE-2026-98340wifi: cfg80211: only group hidden BSSes with beacon entries

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: only group hidden BSSes with beacon entries When a probe response for an unknown BSS comes in, __cfg80211_bss_update() looks for an existing entry with the same BSSID and a hidden (zero-length or NUL-filled) SSID, and if it finds one it groups them, using the beacon IEs from the existing entry. But that could find another entry without a beacon, if it was also from a probe response (with SSID), so there's a group without beacon elements. If a beacon with a hidden SSID for that BSSID arrives later, cfg80211_combine_bsses() goes looking for the probe response entries that belong to it - i.e. entries with the same BSSID and channel that have no beacon IEs - and finds those two. They are already grouped with each other, so it hits its WARN_ON_ONCE(bss->pub.hidden_beacon_bss) WARN_ON_ONCE(!list_empty(&bss->hidden_list)) which are there because an entry without beacon elements is not supposed to be part of a group yet. Only combine entries when a beacon was already received, ones that are kept separate will be combined when a beacon arrives.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/4cd6a518ce7527284bbc9baab5fa2453a7d477c2
• https://git.kernel.org/stable/c/74ed0d992f392c75e1969415527e06df3f7a4034
• https://git.kernel.org/stable/c/3658093df69849daf4f813a8f087f358e13be203
• https://git.kernel.org/stable/c/73365b81630b57e1a1f9d50dc87281797855c2ac
• https://git.kernel.org/stable/c/7405dd19bda4537a2843637d8d7bed1efd4776cf
• https://git.kernel.org/stable/c/86235be788094131912e9bd8412b358d91d99f49
• https://git.kernel.org/stable/c/332ea1502c46f53375cb109fa82bfaff818f3a41
• https://git.kernel.org/stable/c/068843ed0902c552a13860c5ec6b2ca65b57a065