From: WANG Cong <xiyou.wangcong@gmail.com>
Date: Thu, 2 Mar 2017 04:48:39 +0000 (-0800)
Subject: ipv6: ignore null_entry in inet6_rtm_getroute() too
X-Git-Tag: v4.11-rc1~1^2~15
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9d6acb3bc9058d1fd7a5297d71f14213679bb4bd;p=karo-tx-linux.git

ipv6: ignore null_entry in inet6_rtm_getroute() too

Like commit 1f17e2f2c8a8 ("net: ipv6: ignore null_entry on route dumps"),
we need to ignore null entry in inet6_rtm_getroute() too.

Return -ENETUNREACH here to sync with IPv4 behavior, as suggested by David.

Fixes: a1a22c1206 ("net: ipv6: Keep nexthop of multipath route on admin down")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 43ca90d50ae9..229bfcc451ef 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3632,6 +3632,12 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
 		rt = (struct rt6_info *)ip6_route_output(net, NULL, &fl6);
 	}
 
+	if (rt == net->ipv6.ip6_null_entry) {
+		err = rt->dst.error;
+		ip6_rt_put(rt);
+		goto errout;
+	}
+
 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!skb) {
 		ip6_rt_put(rt);