wifi: mac80211: bounds-check link_id in ieee80211_ml_reconfiguration

link_id is taken from the ML Reconfiguration element (control & 0x000f),
so it can be 0..15. link_removal_timeout[] has IEEE80211_MLD_MAX_NUM_LINKS
(15) elements, so index 15 is out-of-bounds. Skip subelements with
link_id >= IEEE80211_MLD_MAX_NUM_LINKS to avoid a stack out-of-bounds
write.

Fixes: 8eb8dd2 ("wifi: mac80211: Support link removal using Reconfiguration ML element")
Reported-by: Ariel Silver <[email protected]>
Signed-off-by: Ariel Silver <[email protected]>
Cc: [email protected]
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Johannes Berg <[email protected]>

Author: SilverPlate3

net/mac80211/mlme.c

@@ -7085,6 +7085,9 @@ static void ieee80211_ml_reconfiguration(struct ieee80211_sub_if_data *sdata,
 		control = le16_to_cpu(prof->control);
 		link_id = control & IEEE80211_MLE_STA_RECONF_CONTROL_LINK_ID;
 
+		if (link_id >= IEEE80211_MLD_MAX_NUM_LINKS)
+			continue;
+
 		removed_links |= BIT(link_id);
 
 		/* the MAC address should not be included, but handle it */