From: Felix Fietkau <nbd@nbd.name>
Date: Mon, 11 Oct 2021 10:07:46 +0000 (+0200)
Subject: mt76: do not access 802.11 header in ccmp check for 802.3 rx skbs
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7360cdec1cb55ae1e9515ffffc496c5dd0cf861a;p=linux.git

mt76: do not access 802.11 header in ccmp check for 802.3 rx skbs

Avoids false positive on detecting frags or encrypted mgmt frames

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

diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c
index 5a6608f36ebc3..766681a4f89ec 100644
--- a/drivers/net/wireless/mediatek/mt76/mac80211.c
+++ b/drivers/net/wireless/mediatek/mt76/mac80211.c
@@ -974,6 +974,10 @@ mt76_check_ccmp_pn(struct sk_buff *skb)
 	if (!wcid || !wcid->rx_check_pn)
 		return 0;
 
+	security_idx = status->qos_ctl & IEEE80211_QOS_CTL_TID_MASK;
+	if (status->flag & RX_FLAG_8023)
+		goto skip_hdr_check;
+
 	hdr = mt76_skb_get_hdr(skb);
 	if (!(status->flag & RX_FLAG_IV_STRIPPED)) {
 		/*
@@ -994,9 +998,8 @@ mt76_check_ccmp_pn(struct sk_buff *skb)
 	if (ieee80211_is_mgmt(hdr->frame_control) &&
 	    !ieee80211_has_tods(hdr->frame_control))
 		security_idx = IEEE80211_NUM_TIDS;
-	else
-		security_idx = status->qos_ctl & IEEE80211_QOS_CTL_TID_MASK;
 
+skip_hdr_check:
 	BUILD_BUG_ON(sizeof(status->iv) != sizeof(wcid->rx_key_pn[0]));
 	ret = memcmp(status->iv, wcid->rx_key_pn[security_idx],
 		     sizeof(status->iv));