From 69ec932e364b1ba9c3a2085fe96b76c8a3f71e7c Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Sun, 23 Jul 2017 17:52:23 +0800 Subject: [PATCH] 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: 7f8a436eaa2c ("openvswitch: Add conntrack action") Signed-off-by: Liping Zhang Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- net/openvswitch/conntrack.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c index e3c4c6c3fef7..03859e386b47 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -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)", -- 2.39.5