This is a note to let you know that I've just added the patch titled
net: ipv4: Make "ip route get" match iif lo rules again.
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: net-ipv4-make-ip-route-get-match-iif-lo-rules-again.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Sun Jan 28 17:35:08 CET 2018
From: Lorenzo Colitti lorenzo@google.com Date: Thu, 11 Jan 2018 18:36:26 +0900 Subject: net: ipv4: Make "ip route get" match iif lo rules again.
From: Lorenzo Colitti lorenzo@google.com
[ Upstream commit 6503a30440962f1e1ccb8868816b4e18201218d4 ]
Commit 3765d35ed8b9 ("net: ipv4: Convert inet_rtm_getroute to rcu versions of route lookup") broke "ip route get" in the presence of rules that specify iif lo.
Host-originated traffic always has iif lo, because ip_route_output_key_hash and ip6_route_output_flags set the flow iif to LOOPBACK_IFINDEX. Thus, putting "iif lo" in an ip rule is a convenient way to select only originated traffic and not forwarded traffic.
inet_rtm_getroute used to match these rules correctly because even though it sets the flow iif to 0, it called ip_route_output_key which overwrites iif with LOOPBACK_IFINDEX. But now that it calls ip_route_output_key_hash_rcu, the ifindex will remain 0 and not match the iif lo in the rule. As a result, "ip route get" will return ENETUNREACH.
Fixes: 3765d35ed8b9 ("net: ipv4: Convert inet_rtm_getroute to rcu versions of route lookup") Tested: https://android.googlesource.com/kernel/tests/+/master/net/test/multinetwork... passes again Signed-off-by: Lorenzo Colitti lorenzo@google.com Acked-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/route.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2762,6 +2762,7 @@ static int inet_rtm_getroute(struct sk_b if (err == 0 && rt->dst.error) err = -rt->dst.error; } else { + fl4.flowi4_iif = LOOPBACK_IFINDEX; rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); err = 0; if (IS_ERR(rt))
Patches currently in stable-queue which might be from lorenzo@google.com are
queue-4.14/net-ipv4-make-ip-route-get-match-iif-lo-rules-again.patch