[PATCH 4.14 205/315] mac80211: fix memory corruption in EAPOL handling

From: Davis Mosenkovs <redacted>

Commit e3d4030498c3 ("mac80211: do not accept/forward invalid EAPOL
frames") uses skb_mac_header() before eth_type_trans() is called
leading to incorrect pointer, the pointer gets written to. This issue
has appeared during backporting to 4.4, 4.9 and 4.14.

Fixes: e3d4030498c3 ("mac80211: do not accept/forward invalid EAPOL frames")
Link: https://lore.kernel.org/r/CAHQn7pKcyC_jYmGyTcPCdk9xxATwW5QPNph=bsZV8d-HPwNsyA@mail.gmail.com (local)
Cc: <redacted> # 4.4.x
Signed-off-by: Davis Mosenkovs <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/mac80211/rx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c

@@ -2404,7 +2404,7 @@ ieee80211_deliver_skb(struct ieee80211_r
 #endif
 
 	if (skb) {
-		struct ethhdr *ehdr = (void *)skb_mac_header(skb);
+		struct ethhdr *ehdr = (struct ethhdr *)skb->data;
 
 		/* deliver to local stack */
 		skb->protocol = eth_type_trans(skb, dev);