From 39e695c8e1d0d3a17a76224aa33e3c6c99645826 Mon Sep 17 00:00:00 2001 From: David Bauer Date: Thu, 18 Apr 2024 15:29:08 +0200 Subject: [PATCH] vxlan: drop packets from invalid src-address [ Upstream commit f58f45c1e5b92975e91754f5407250085a6ae7cf ] The VXLAN driver currently does not check if the inner layer2 source-address is valid. In case source-address snooping/learning is enabled, a entry in the FDB for the invalid address is created with the layer3 address of the tunnel endpoint. If the frame happens to have a non-unicast address set, all this non-unicast traffic is subsequently not flooded to the tunnel network but sent to the learnt host in the FDB. To make matters worse, this FDB entry does not expire. Apply the same filtering for packets as it is done for bridges. This not only drops these invalid packets but avoids them from being learnt into the FDB. Fixes: d342894c5d2f ("vxlan: virtual extensible lan") Suggested-by: Ido Schimmel Signed-off-by: David Bauer Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/vxlan/vxlan_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index 3096769e7..b173497a3 100755 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -1778,6 +1778,10 @@ 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;