From a10a2f80476d166fd81c361ec0319493671b694e Mon Sep 17 00:00:00 2001 From: Zhao Li Date: Thu, 10 Sep 2026 14:52:51 +0800 Subject: [PATCH] wifi: mac80211: keep fallback association elements alive Associating to a non-transmitted MBSSID profile reads freed memory while determining the operating channel and applying HT capabilities. When an association response omits WMM, HT, or VHT information, ieee80211_assoc_config_link() parses the cached BSS IEs and copies the missing element pointers out of that fallback parse. For a non-transmitted MBSSID profile those pointers refer to merged-profile storage owned by the parse object, and the fallback block frees that object at its end. The copied pointers are used afterwards to determine the operating channel, configure bandwidth, and apply HT capabilities. Keep the fallback parse result alive until association setup finishes. Fixes: 5023b14cf4df ("mac80211: support profile split between elements") Cc: stable@kernel.org Assisted-by: LLM sparse kasan [reorder variable declaration] Signed-off-by: Zhao Li Signed-off-by: Johannes Berg --- net/mac80211/mlme.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index f51167f0fc46..3c31c16860ab 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -5877,6 +5877,7 @@ static bool ieee80211_assoc_config_link(struct ieee80211_link_data *link, bool is_6ghz = cbss->channel->band == NL80211_BAND_6GHZ; bool is_s1g = cbss->channel->band == NL80211_BAND_S1GHZ; const struct cfg80211_bss_ies *bss_ies = NULL; + struct ieee802_11_elems *bss_elems = NULL; struct ieee80211_supported_band *sband; struct ieee802_11_elems *elems; u16 capab_info; @@ -6007,7 +6008,6 @@ static bool ieee80211_assoc_config_link(struct ieee80211_link_data *link, (is_5ghz && link->u.mgd.conn.mode >= IEEE80211_CONN_MODE_VHT && (!elems->vht_cap_elem || !elems->vht_operation)))) { const struct cfg80211_bss_ies *ies; - struct ieee802_11_elems *bss_elems; rcu_read_lock(); ies = rcu_dereference(cbss->ies); @@ -6069,7 +6069,6 @@ static bool ieee80211_assoc_config_link(struct ieee80211_link_data *link, "AP bug: VHT operation missing from AssocResp\n"); } } - kfree(bss_elems); } /* @@ -6342,6 +6341,7 @@ static bool ieee80211_assoc_config_link(struct ieee80211_link_data *link, ret = true; out: kfree(elems); + kfree(bss_elems); kfree(bss_ies); return ret; }