Commit 5551cb1c68d4 ("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: 5551cb1c68d4 ("mac80211: do not accept/forward invalid EAPOL frames") Link: https://lore.kernel.org/r/CAHQn7pKcyC_jYmGyTcPCdk9xxATwW5QPNph=bsZV8d-HPwNsy... Cc: stable@vger.kernel.org # 4.9.x Signed-off-by: Davis Mosenkovs davis@mosenkovs.lv --- net/mac80211/rx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 3a069cb188b7..b40e71a5d795 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2380,7 +2380,7 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx) #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);