[PATCH] net/ping: handle protocol mismatching scenario

From: Jane Zhou
Date: Mon Nov 24 2014 - 14:44:28 EST


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@xxxxxxxxxxxxx>
Cc: Alexey Kuznetsov <kuznet@xxxxxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: Hideaki YOSHIFUJI <yoshfuji@xxxxxxxxxxxxxx>
Cc: Patrick McHardy <kaber@xxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jane Zhou <a17711@xxxxxxxxxxxx>
Signed-off-by: Yiwei Zhao <gbjc64@xxxxxxxxxxxx>
---
net/ipv4/ping.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index fc1c4b1..8892913 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -214,6 +214,8 @@ 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)
--
1.8.0

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