[PATCH 3.16 174/328] cfg80211: nl80211_update_ft_ies() to validate NL80211_ATTR_IE

[Ben Hutchings]

3.16.62-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Arunk Khandavalli <akhandav@xxxxxxxxxxxxxx>

commit 4f0223bfe9c3e62d8f45a85f1ef1b18a8a263ef9 upstream.

nl80211_update_ft_ies() tried to validate NL80211_ATTR_IE with
is_valid_ie_attr() before dereferencing it, but that helper function
returns true in case of NULL pointer (i.e., attribute not included).
This can result to dereferencing a NULL pointer. Fix that by explicitly
checking that NL80211_ATTR_IE is included.

Fixes: 355199e02b83 ("cfg80211: Extend support for IEEE 802.11r Fast BSS Transition")
Signed-off-by: Arunk Khandavalli <akhandav@xxxxxxxxxxxxxx>
Signed-off-by: Jouni Malinen <jouni@xxxxxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 net/wireless/nl80211.c | 1 +
 1 file changed, 1 insertion(+)

--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -9185,6 +9185,7 @@ static int nl80211_update_ft_ies(struct
 		return -EOPNOTSUPP;
 
 	if (!info->attrs[NL80211_ATTR_MDID] ||
+	    !info->attrs[NL80211_ATTR_IE] ||
 	    !is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
 		return -EINVAL;