On Fri, May 31, 2024 at 05:41:37PM +0200, Daniel Borkmann wrote:
> diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
> index f78dd0438843..7353f27b02dc 100644
> --- a/drivers/net/vxlan/vxlan_core.c
> +++ b/drivers/net/vxlan/vxlan_core.c
> @@ -1605,6 +1605,7 @@ static bool vxlan_set_mac(struct vxlan_dev *vxlan,
> struct vxlan_sock *vs,
> struct sk_buff *skb, __be32 vni)
> {
> + bool learning = vxlan->cfg.flags & VXLAN_F_LEARN;
> union vxlan_addr saddr;
> u32 ifindex = skb->dev->ifindex;
>
> @@ -1616,8 +1617,11 @@ static bool vxlan_set_mac(struct vxlan_dev *vxlan,
> if (ether_addr_equal(eth_hdr(skb)->h_source, vxlan->dev->dev_addr))
> return false;
>
> - /* Ignore packets from invalid src-address */
> - if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
> + /* Ignore packets from invalid src-address when in learning mode,
> + * otherwise let them through e.g. when originating from NOARP
> + * devices with all-zero mac, etc.
> + */
> + if (learning && !is_valid_ether_addr(eth_hdr(skb)->h_source))
> return false;
>
> /* Get address from the outer IP header */
> @@ -1631,7 +1635,7 @@ static bool vxlan_set_mac(struct vxlan_dev *vxlan,
> #endif
> }
>
> - if ((vxlan->cfg.flags & VXLAN_F_LEARN) &&
> + if (learning &&
> vxlan_snoop(skb->dev, &saddr, eth_hdr(skb)->h_source, ifindex, vni))
> return false;
Daniel, I think we can simply move this check out of the main path to
vxlan_snoop() which is only called when learning is enabled:
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 7496c14e8329..89f3945b448f 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1446,6 +1446,10 @@ static bool vxlan_snoop(struct net_device *dev,
struct vxlan_fdb *f;
u32 ifindex = 0;
+ /* Ignore packets from invalid src-address */
+ if (!is_valid_ether_addr(src_mac))
+ return true;
+
#if IS_ENABLED(CONFIG_IPV6)
if (src_ip->sa.sa_family == AF_INET6 &&
(ipv6_addr_type(&src_ip->sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL))
@@ -1616,10 +1620,6 @@ static bool vxlan_set_mac(struct vxlan_dev *vxlan,
if (ether_addr_equal(eth_hdr(skb)->h_source, vxlan->dev->dev_addr))
return false;
- /* Ignore packets from invalid src-address */
- if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
- return false;
-
/* Get address from the outer IP header */
if (vxlan_get_sk_family(vs) == AF_INET) {
saddr.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
WDYT?
