mac80211: Only process mesh config header on frames that RA_MATCH

commit 555cb715 upstream.

Doing otherwise is wrong, and may wreak havoc on the mpp tables,
specially if the frame is encrypted.
Reported-by: Chaoxing Lin <Chaoxing.Lin@ultra-3eti.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[bwh: Backported to 3.2: we have a large block conditional on
 IEEE80211_RX_RA_MATCH rather than a goto conditional on the opposite,
 so delete the condition]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

net/mac80211/rx.c

@@ -1895,7 +1895,8 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
 	    mesh_rmc_check(hdr->addr3, mesh_hdr, rx->sdata))
 		return RX_DROP_MONITOR;
 
-	if (!ieee80211_is_data(hdr->frame_control))
+	if (!ieee80211_is_data(hdr->frame_control) ||
+	    !(status->rx_flags & IEEE80211_RX_RA_MATCH))
 		return RX_CONTINUE;
 
 	if (!mesh_hdr->ttl)
@@ -1941,7 +1942,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
 
 	mesh_hdr->ttl--;
 
-	if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
+	{
 		if (!mesh_hdr->ttl)
 			IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
 						     dropped_frames_ttl);