diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index c646094a5fc4765081553a2e8cef236c9656b7da..af81cf81f68ff21262c11fa77fce24fcdf4fbe66 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -3163,10 +3163,14 @@ int cfg80211_wext_siwscan(struct net_device *dev,
 	wiphy = &rdev->wiphy;
 
 	/* Determine number of channels, needed to allocate creq */
-	if (wreq && wreq->num_channels)
+	if (wreq && wreq->num_channels) {
+		/* Passed from userspace so should be checked */
+		if (unlikely(wreq->num_channels > IW_MAX_FREQUENCIES))
+			return -EINVAL;
 		n_channels = wreq->num_channels;
-	else
+	} else {
 		n_channels = ieee80211_get_num_supported_channels(wiphy);
+	}
 
 	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
 		       n_channels * sizeof(void *),