[NETFILTER]: Fix routing of REJECT target generated packets in output chain

Packets generated by the REJECT target in the output chain have a local
destination address and a foreign source address. Make sure not to use
the foreign source address for the output route lookup.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 2 deletions

diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index a68966059b50..c47ce7076bd5 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -15,16 +15,19 @@ int ip_route_me_harder(struct sk_buff **pskb, unsigned addr_type)
         struct flowi fl = {};
         struct dst_entry *odst;
         unsigned int hh_len;
+        unsigned int type;
 
+        type = inet_addr_type(iph->saddr);
         if (addr_type == RTN_UNSPEC)
-                addr_type = inet_addr_type(iph->saddr);
+                addr_type = type;
 
         /* some non-standard hacks like ipt_REJECT.c:send_reset() can cause
          * packets with foreign saddr to appear on the NF_IP_LOCAL_OUT hook.
          */
         if (addr_type == RTN_LOCAL) {
                 fl.nl_u.ip4_u.daddr = iph->daddr;
-                fl.nl_u.ip4_u.saddr = iph->saddr;
+                if (type == RTN_LOCAL)
+                        fl.nl_u.ip4_u.saddr = iph->saddr;
                 fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
                 fl.oif = (*pskb)->sk ? (*pskb)->sk->sk_bound_dev_if : 0;
                 fl.mark = (*pskb)->mark;