openvswitch: fix potential out of bound access in parse_ct

Before the 'type' is validated, we shouldn't use it to fetch the
ovs_ct_attr_lens's minlen and maxlen, else, out of bound access
may happen.

Fixes: 7f8a436eaa ("openvswitch: Add conntrack action")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Liping Zhang 2017-07-23 17:52:23 +08:00 committed by David S. Miller
parent 9476d39366
commit 69ec932e36

View File

@ -1310,8 +1310,8 @@ static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
nla_for_each_nested(a, attr, rem) {
int type = nla_type(a);
int maxlen = ovs_ct_attr_lens[type].maxlen;
int minlen = ovs_ct_attr_lens[type].minlen;
int maxlen;
int minlen;
if (type > OVS_CT_ATTR_MAX) {
OVS_NLERR(log,
@ -1319,6 +1319,9 @@ static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
type, OVS_CT_ATTR_MAX);
return -EINVAL;
}
maxlen = ovs_ct_attr_lens[type].maxlen;
minlen = ovs_ct_attr_lens[type].minlen;
if (nla_len(a) < minlen || nla_len(a) > maxlen) {
OVS_NLERR(log,
"Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",