nl80211: fix HT capability attribute validation

commit 6c7394197af90f6a332180e33f5d025d3037d883 upstream.

Since the NL80211_ATTR_HT_CAPABILITY attribute is
used as a struct, it needs a minimum, not maximum
length. Enforce that properly. Not doing so could
potentially lead to reading after the buffer.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 1ac9443b5265c11f1a22af4cac1e720688ba8d1a..3dac76f33b947ceda2b4f566aa1595520c1cb2f1 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -126,8 +126,7 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
        [NL80211_ATTR_MESH_CONFIG] = { .type = NLA_NESTED },
        [NL80211_ATTR_SUPPORT_MESH_AUTH] = { .type = NLA_FLAG },
 
-       [NL80211_ATTR_HT_CAPABILITY] = { .type = NLA_BINARY,
-                                        .len = NL80211_HT_CAPABILITY_LEN },
+       [NL80211_ATTR_HT_CAPABILITY] = { .len = NL80211_HT_CAPABILITY_LEN },
 
        [NL80211_ATTR_MGMT_SUBTYPE] = { .type = NLA_U8 },
        [NL80211_ATTR_IE] = { .type = NLA_BINARY,