mac80211: mesh: drop frames appearing to be from us

Upstream backport to fix issues arising from devices with duplicate MAC
addresses

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/kernel/mac80211/patches/323-mac80211-mesh-drop-frames-appearing-to-be-from-us.patch

@@ -0,0 +1,25 @@
+From: Johannes Berg <johannes.berg@intel.com>
+Date: Thu, 4 Jan 2018 15:51:53 +0100
+Subject: [PATCH] mac80211: mesh: drop frames appearing to be from us
+
+If there are multiple mesh stations with the same MAC address,
+they will both get confused and start throwing warnings.
+
+Obviously in this case nothing can actually work anyway, so just
+drop frames that look like they're from ourselves early on.
+
+Reported-by: Gui Iribarren <gui@altermundi.net>
+Signed-off-by: Johannes Berg <johannes.berg@intel.com>
+---
+
+--- a/net/mac80211/rx.c
++++ b/net/mac80211/rx.c
+@@ -3632,6 +3632,8 @@ static bool ieee80211_accept_frame(struc
+ 		}
+ 		return true;
+ 	case NL80211_IFTYPE_MESH_POINT:
++		if (ether_addr_equal(sdata->vif.addr, hdr->addr2))
++			return false;
+ 		if (multicast)
+ 			return true;
+ 		return ether_addr_equal(sdata->vif.addr, hdr->addr1);