ipvs: ensure that ICMP cannot be sent in reply to ICMP

Check the header for icmp before sending a PACKET_TOO_BIG

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index af5e9d3b4de93fcad651c2d32186bee9cf049e14..c5be055ae32eda8fe41ba314ba1f9ecada8e84ee 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -224,7 +224,7 @@ static inline bool ensure_mtu_is_adequate(int skb_af, int rt_mode,
                        if (!skb->dev)
                                skb->dev = net->loopback_dev;
                        /* only send ICMP too big on first fragment */
-                       if (!ipvsh->fragoffs)
+                       if (!ipvsh->fragoffs && !ip_vs_iph_icmp(ipvsh))
                                icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
                        IP_VS_DBG(1, "frag needed for %pI6c\n",
                                  &ipv6_hdr(skb)->saddr);
@@ -242,7 +242,8 @@ static inline bool ensure_mtu_is_adequate(int skb_af, int rt_mode,
                        return true;
 
                if (unlikely(ip_hdr(skb)->frag_off & htons(IP_DF) &&
-                            skb->len > mtu && !skb_is_gso(skb))) {
+                            skb->len > mtu && !skb_is_gso(skb) &&
+                            !ip_vs_iph_icmp(ipvsh))) {
                        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
                                  htonl(mtu));
                        IP_VS_DBG(1, "frag needed for %pI4\n",