Commit b860d3cc authored Apr 07, 2013 by Mathias Krause Committed by David S. Miller Apr 07, 2013

l2tp: fix info leak in l2tp_ip6_recvmsg()



The L2TP code for IPv6 fails to initialize the l2tp_conn_id member of
struct sockaddr_l2tpip6 and therefore leaks four bytes kernel stack
in l2tp_ip6_recvmsg() in case msg_name is set.

Initialize l2tp_conn_id with 0 to avoid the info leak.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a5598bd9

net/l2tp/l2tp_ip6.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -690,6 +690,7 @@ static int l2tp_ip6_recvmsg(struct kiocb iocb, struct sock sk,
		lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
		lsa->l2tp_flowinfo = 0;
		lsa->l2tp_scope_id = 0;
		lsa->l2tp_conn_id = 0;
		if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
		lsa->l2tp_scope_id = IP6CB(skb)->iif;
		}

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