nl80211: check for the required netlink attributes presence

nefigtut · jmberg-intel · commit e785fa0a164a · 2017-09-15T09:15:14.000+02:00
nl80211_set_rekey_data() does not check if the required attributes NL80211_REKEY_DATA_{REPLAY_CTR,KEK,KCK} are present when processing NL80211_CMD_SET_REKEY_OFFLOAD request. This request can be issued by users with CAP_NET_ADMIN privilege and may result in NULL dereference and a system crash. Add a check for the required attributes presence. This patch is based on the patch by bo Zhang. This fixes CVE-2017-12153. References: https://bugzilla.redhat.com/show_bug.cgi?id=1491046 Fixes: e5497d7 ("cfg80211/nl80211: support GTK rekey offload") Cc: <stable@vger.kernel.org> # v3.1-rc1 Reported-by: bo Zhang <zhangbo5891001@gmail.com> Signed-off-by: Vladis Dronov <vdronov@redhat.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
@@ -10903,6 +10903,9 @@ static int nl80211_set_rekey_data(struct sk_buff *skb, struct genl_info *info)
 	if (err)
 		return err;
 
+	if (!tb[NL80211_REKEY_DATA_REPLAY_CTR] || !tb[NL80211_REKEY_DATA_KEK] ||
+	    !tb[NL80211_REKEY_DATA_KCK])
+		return -EINVAL;
 	if (nla_len(tb[NL80211_REKEY_DATA_REPLAY_CTR]) != NL80211_REPLAY_CTR_LEN)
 		return -ERANGE;
 	if (nla_len(tb[NL80211_REKEY_DATA_KEK]) != NL80211_KEK_LEN)
