diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index b28e652514e8..18398968b3ed 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -2243,8 +2243,8 @@ int cfg80211_wext_siwscan(struct net_device *dev,
 		n_channels = ieee80211_get_num_supported_channels(wiphy);
 	}
 
-	creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) +
-		       n_channels * sizeof(void *),
+	creq = kzalloc(struct_size(creq, channels, n_channels) +
+		       sizeof(struct cfg80211_ssid),
 		       GFP_ATOMIC);
 	if (!creq) {
 		err = -ENOMEM;
@@ -2254,7 +2254,7 @@ int cfg80211_wext_siwscan(struct net_device *dev,
 	creq->wiphy = wiphy;
 	creq->wdev = dev->ieee80211_ptr;
 	/* SSIDs come after channels */
-	creq->ssids = (void *)&creq->channels[n_channels];
+	creq->ssids = (void *)creq + struct_size(creq, channels, n_channels);
 	creq->n_channels = n_channels;
 	creq->n_ssids = 1;
 	creq->scan_start = jiffies;