Commit f8d54afc authored Mar 06, 2015 by Robert Shearman Committed by David S. Miller Mar 06, 2015

mpls: Properly validate RTA_VIA payload length



If the nla length is less than 2 then the nla data could be accessed
beyond the accessible bounds. So ensure that the nla is big enough to
at least read the via_family before doing so. Replace magic value of
2.

Fixes: 03c05665 ("mpls: Basic support for adding and removing routes")
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5c4b934f

net/mpls/af_mpls.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -586,8 +586,11 @@ static int rtm_to_route_config(struct sk_buff skb, struct nlmsghdr nlh,
		case RTA_VIA:
		{
		struct rtvia *via = nla_data(nla);
		if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
		goto errout;
		cfg->rc_via_family = via->rtvia_family;
		cfg->rc_via_alen = nla_len(nla) - 2;
		cfg->rc_via_alen = nla_len(nla) -
		offsetof(struct rtvia, rtvia_addr);
		if (cfg->rc_via_alen > MAX_VIA_ALEN)
		goto errout;