netdev - [PATCH net] macvlan: use skb_reset_mac_header() in macvlan_queue

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Message-Id: <20200114210035.65042-1-edumazet@google.com>
Date:   Tue, 14 Jan 2020 13:00:35 -0800
From:   Eric Dumazet <edumazet@...gle.com>
To:     "David S . Miller" <davem@...emloft.net>
Cc:     netdev <netdev@...r.kernel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        Eric Dumazet <eric.dumazet@...il.com>,
        Jurgen Van Ham <juvanham@...il.com>
Subject: [PATCH net] macvlan: use skb_reset_mac_header() in macvlan_queue_xmit()

I missed the fact that macvlan_broadcast() can be used both
in RX and TX.

skb_eth_hdr() makes only sense in TX paths, so we can not
use it blindly in macvlan_broadcast()

Fixes: 96cc4b69581d ("macvlan: do not assume mac_header is set in macvlan_broadcast()")
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Reported-by: Jurgen Van Ham <juvanham@...il.com>
---
 drivers/net/macvlan.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 747c0542a53c763676d491c91a5b704f0eb9848e..c5bf61565726b15aa1ea63590d7d8627b0c20d4a 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -259,7 +259,7 @@ static void macvlan_broadcast(struct sk_buff *skb,
 			      struct net_device *src,
 			      enum macvlan_mode mode)
 {
-	const struct ethhdr *eth = skb_eth_hdr(skb);
+	const struct ethhdr *eth = eth_hdr(skb);
 	const struct macvlan_dev *vlan;
 	struct sk_buff *nskb;
 	unsigned int i;
@@ -513,10 +513,11 @@ static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
 	const struct macvlan_dev *dest;
 
 	if (vlan->mode == MACVLAN_MODE_BRIDGE) {
-		const struct ethhdr *eth = (void *)skb->data;
+		const struct ethhdr *eth = skb_eth_hdr(skb);
 
 		/* send to other bridge ports directly */
 		if (is_multicast_ether_addr(eth->h_dest)) {
+			skb_reset_mac_header(skb);
 			macvlan_broadcast(skb, port, dev, MACVLAN_MODE_BRIDGE);
 			goto xmit_world;
 		}
-- 
2.25.0.rc1.283.g88dfdc4193-goog