[PATCH 4.4 63/76] macvlan: use skb_reset_mac_header() in macvlan_queue_xmit()

Greg Kroah-Hartman
2020-01-22T09:55:44Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 1712b2fff8c682d145c7889d2290696647d82dab ]

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@google.com>
Reported-by: Jurgen Van Ham <juvanham@gmail.com>
Tested-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/macvlan.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -233,7 +233,7 @@ static void macvlan_broadcast(struct sk_
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;
@@ -476,10 +476,11 @@ static int macvlan_queue_xmit(struct sk_
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;
}