wifi: mac80211: fix potential sta-link leak

[ Upstream commit b01a74b3ca6fd51b62c67733ba7c3280fa6c5d26 ]

When a station is allocated, links are added but not
set to valid yet (e.g. during connection to an AP MLD),
we might remove the station without ever marking links
valid, and leak them. Fix that.

Fixes: cb71f1d136a6 ("wifi: mac80211: add sta link addition/removal")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240111181514.6573998beaf8.I09ac2e1d41c80f82a5a616b8bd1d9d8dd709a6a6@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 0c5cc75..e112300 100644 (file)
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -398,7 +398,10 @@ void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
        int i;
 
        for (i = 0; i < ARRAY_SIZE(sta->link); i++) {
-               if (!(sta->sta.valid_links & BIT(i)))
+               struct link_sta_info *link_sta;
+
+               link_sta = rcu_access_pointer(sta->link[i]);
+               if (!link_sta)
                        continue;
 
                sta_remove_link(sta, i, false);