[PATCH 3.17 100/122] net/ping: handle protocol mismatching scenario

From: Greg Kroah-Hartman
Date: Fri Dec 05 2014 - 17:47:45 EST


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

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

From: Jane Zhou <a17711@xxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Cc: Alexey Kuznetsov <kuznet@xxxxxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: Hideaki YOSHIFUJI <yoshfuji@xxxxxxxxxxxxxx>
Cc: Patrick McHardy <kaber@xxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Jane Zhou <a17711@xxxxxxxxxxxx>
Signed-off-by: Yiwei Zhao <gbjc64@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/ipv4/ping.c | 2 ++
1 file changed, 2 insertions(+)

--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -217,6 +217,8 @@ static struct sock *ping_lookup(struct n
&ipv6_hdr(skb)->daddr))
continue;
#endif
+ } else {
+ continue;
}

if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)


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