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 5a6608f36ebc3a72463520876cb8cce260a53eac..766681a4f89ecfc9eea91fb0278b6062f4f982e7 100644 (file)
--- 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));