From 1158632b5a2dcce0786c1b1b99654e81cc867981 Mon Sep 17 00:00:00 2001 From: Brian Russell Date: Fri, 24 Feb 2017 17:47:11 +0000 Subject: [PATCH] vxlan: don't allow overwrite of config src addr When using IPv6 transport and a default dst, a pointer to the configured source address is passed into the route lookup. If no source address is configured, then the value is overwritten. IPv6 route lookup ignores egress ifindex match if the source address is set, so if egress ifindex match is desired, the source address must be passed as any. The overwrite breaks this for subsequent lookups. Avoid this by copying the configured address to an existing stack variable and pass a pointer to that instead. Fixes: 272d96a5ab10 ("net: vxlan: lwt: Use source ip address during route lookup.") Signed-off-by: Brian Russell Acked-by: Jiri Benc Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 268c2a1..b791199 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -2035,7 +2035,6 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, const struct iphdr *old_iph = ip_hdr(skb); union vxlan_addr *dst; union vxlan_addr remote_ip, local_ip; - union vxlan_addr *src; struct vxlan_metadata _md; struct vxlan_metadata *md = &_md; __be16 src_port = 0, dst_port; @@ -2062,7 +2061,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, dst_port = rdst->remote_port ? rdst->remote_port : vxlan->cfg.dst_port; vni = (rdst->remote_vni) ? : default_vni; - src = &vxlan->cfg.saddr; + local_ip = vxlan->cfg.saddr; dst_cache = &rdst->dst_cache; md->gbp = skb->mark; ttl = vxlan->cfg.ttl; @@ -2095,7 +2094,6 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, dst = &remote_ip; dst_port = info->key.tp_dst ? : vxlan->cfg.dst_port; vni = tunnel_id_to_key32(info->key.tun_id); - src = &local_ip; dst_cache = &info->dst_cache; if (info->options_len) md = ip_tunnel_info_opts(info); @@ -2115,7 +2113,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, rt = vxlan_get_route(vxlan, dev, sock4, skb, rdst ? rdst->remote_ifindex : 0, tos, dst->sin.sin_addr.s_addr, - &src->sin.sin_addr.s_addr, + &local_ip.sin.sin_addr.s_addr, dst_port, src_port, dst_cache, info); if (IS_ERR(rt)) { @@ -2142,7 +2140,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, if (err < 0) goto tx_error; - udp_tunnel_xmit_skb(rt, sock4->sock->sk, skb, src->sin.sin_addr.s_addr, + udp_tunnel_xmit_skb(rt, sock4->sock->sk, skb, local_ip.sin.sin_addr.s_addr, dst->sin.sin_addr.s_addr, tos, ttl, df, src_port, dst_port, xnet, !udp_sum); #if IS_ENABLED(CONFIG_IPV6) @@ -2152,7 +2150,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, ndst = vxlan6_get_route(vxlan, dev, sock6, skb, rdst ? rdst->remote_ifindex : 0, tos, label, &dst->sin6.sin6_addr, - &src->sin6.sin6_addr, + &local_ip.sin6.sin6_addr, dst_port, src_port, dst_cache, info); if (IS_ERR(ndst)) { @@ -2180,7 +2178,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, goto tx_error; udp_tunnel6_xmit_skb(ndst, sock6->sock->sk, skb, dev, - &src->sin6.sin6_addr, + &local_ip.sin6.sin6_addr, &dst->sin6.sin6_addr, tos, ttl, label, src_port, dst_port, !udp_sum); #endif -- 2.7.4