nl80211: Verify radar event attributes exist before using them

While these attributes may be expected to be present always, this needs
to be verified within driver_nl80211.c since we cannot depend on the
kernel/driver working correctly.

Signed-hostap: Jouni Malinen <j@w1.fi>

src/drivers/driver_nl80211.c

@@ -2564,9 +2564,12 @@ static void nl80211_radar_event(struct wpa_driver_nl80211_data *drv,
 	}
 
 	/* Get VHT params */
-	data.dfs_event.chan_width =
-		convert2width(nla_get_u32(tb[NL80211_ATTR_CHANNEL_WIDTH]));
-	data.dfs_event.cf1 = nla_get_u32(tb[NL80211_ATTR_CENTER_FREQ1]);
+	if (tb[NL80211_ATTR_CHANNEL_WIDTH])
+		data.dfs_event.chan_width =
+			convert2width(nla_get_u32(
+					      tb[NL80211_ATTR_CHANNEL_WIDTH]));
+	if (tb[NL80211_ATTR_CENTER_FREQ1])
+		data.dfs_event.cf1 = nla_get_u32(tb[NL80211_ATTR_CENTER_FREQ1]);
 	if (tb[NL80211_ATTR_CENTER_FREQ2])
 		data.dfs_event.cf2 = nla_get_u32(tb[NL80211_ATTR_CENTER_FREQ2]);