wifi: mac80211: fix rx link assignment for non-MLO stations

Currently, ieee80211_rx_data_set_sta() does not correctly handle the
case where the interface supports multiple links (MLO), but the station
does not (non-MLO). This can lead to incorrect link assignment or
unexpected warnings when accessing link information.

Hence, add a fix to check if the station lacks valid link support and
use its default link ID for rx->link assignment. If the station
unexpectedly has valid links, fall back to the default link.

This ensures correct link association and prevents potential issues
in mixed MLO/non-MLO environments.

Signed-off-by: Hari Chandrakanthan <quic_haric@quicinc.com>
Signed-off-by: Sarika Sharma <quic_sarishar@quicinc.com>
Link: https://patch.msgid.link/20250630084119.3583593-1-quic_sarishar@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 8699755081ad6c5915910166f183acfce3189117..caa3e6b3f46e3b378dbb978df59de3976b01472e 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4245,10 +4245,16 @@ static bool ieee80211_rx_data_set_sta(struct ieee80211_rx_data *rx,
                rx->link_sta = NULL;
        }
 
-       if (link_id < 0)
-               rx->link = &rx->sdata->deflink;
-       else if (!ieee80211_rx_data_set_link(rx, link_id))
+       if (link_id < 0) {
+               if (ieee80211_vif_is_mld(&rx->sdata->vif) &&
+                   sta && !sta->sta.valid_links)
+                       rx->link =
+                               rcu_dereference(rx->sdata->link[sta->deflink.link_id]);
+               else
+                       rx->link = &rx->sdata->deflink;
+       } else if (!ieee80211_rx_data_set_link(rx, link_id)) {
                return false;
+       }
 
        return true;
 }