[PATCH 3.16.y-ckt 111/168] net/ping: handle protocol mismatching scenario

[Luis Henriques]

3.16.7-ckt3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jane Zhou <a17711 at motorola.com>

commit 91a0b603469069cdcce4d572b7525ffc9fd352a6 upstream.

ping_lookup() may return a wrong sock if sk_buff's and sock's protocols
dont' match. For example, sk_buff's protocol is ETH_P_IPV6, but sock's
sk_family is AF_INET, in that case, if sk->sk_bound_dev_if is zero, a wrong
sock will be returned.
the fix is to "continue" the searching, if no matching, return NULL.

Cc: "David S. Miller" <davem at davemloft.net>
Cc: Alexey Kuznetsov <kuznet at ms2.inr.ac.ru>
Cc: James Morris <jmorris at namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji at linux-ipv6.org>
Cc: Patrick McHardy <kaber at trash.net>
Cc: netdev at vger.kernel.org
Signed-off-by: Jane Zhou <a17711 at motorola.com>
Signed-off-by: Yiwei Zhao <gbjc64 at motorola.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv4/ping.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 044a0ddf6a79..620e8ffa62e8 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -217,6 +217,8 @@ static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
 					     &ipv6_hdr(skb)->daddr))
 				continue;
 #endif
+		} else {
+			continue;
 		}
 
 		if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
-- 
2.1.3