This is a note to let you know that I've just added the patch titled net: ipv4: fix multipath RTM_GETROUTE behavior when iif is given to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-ipv4-fix-multipath-rtm_getroute-behavior-when-iif-is-given.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sun Apr 30 15:46:17 CEST 2017 From: Florian Larysch <fl@xxxxxxx> Date: Mon, 3 Apr 2017 16:46:09 +0200 Subject: net: ipv4: fix multipath RTM_GETROUTE behavior when iif is given From: Florian Larysch <fl@xxxxxxx> [ Upstream commit a8801799c6975601fd58ae62f48964caec2eb83f ] 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 <fl@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/route.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2559,7 +2559,7 @@ static int inet_rtm_getroute(struct sk_b 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; Patches currently in stable-queue which might be from fl@xxxxxxx are queue-4.4/net-ipv4-fix-multipath-rtm_getroute-behavior-when-iif-is-given.patch