inet_rtm_getroute synthesizes a skeletal ICMP skb, which is passed to
ip_route_input when iif is given. If a multipath route is present for
the designated destination, ip_multipath_icmp_hash ends up being called,
which uses the source/destination addresses within the skb to calculate
a hash. However, those are not set in the synthetic skb, causing it to
return an arbitrary and incorrect result.
Instead, use UDP, which gets no such special treatment.
Signed-off-by: Florian Larysch <f...@n621.de>
---
net/ipv4/route.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 8471dd116771..acd69cfe2951 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2620,7 +2620,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb,
struct nlmsghdr *nlh)
skb_reset_network_header(skb);
/* Bugfix: need to give ip_route_input enough of an IP header to not
gag. */
- ip_hdr(skb)->protocol = IPPROTO_ICMP;
+ ip_hdr(skb)->protocol = IPPROTO_UDP;
skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
--
2.12.0
