From 7360cdec1cb55ae1e9515ffffc496c5dd0cf861a Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Mon, 11 Oct 2021 12:07:46 +0200
Subject: [PATCH] mt76: do not access 802.11 header in ccmp check for 802.3 rx skbs
Git-commit: 7360cdec1cb55ae1e9515ffffc496c5dd0cf861a
Patch-mainline: v5.16-rc1
References: bsc#1209980
Avoids false positive on detecting frags or encrypted mgmt frames
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/wireless/mediatek/mt76/mac80211.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c
index 5a6608f36ebc..766681a4f89e 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));
--
2.35.3