diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 3da1c5c45035..8ecc4b710b0e 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -744,15 +744,21 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 			local->hw_scan_ies_bufsize *= n_bands;
 		}
 
-		local->hw_scan_req = kmalloc(
-				sizeof(*local->hw_scan_req) +
-				req->n_channels * sizeof(req->channels[0]) +
-				local->hw_scan_ies_bufsize, GFP_KERNEL);
+		local->hw_scan_req = kmalloc(struct_size(local->hw_scan_req,
+							 req.channels,
+							 req->n_channels) +
+					     local->hw_scan_ies_bufsize,
+					     GFP_KERNEL);
 		if (!local->hw_scan_req)
 			return -ENOMEM;
 
 		local->hw_scan_req->req.ssids = req->ssids;
 		local->hw_scan_req->req.n_ssids = req->n_ssids;
+		/* None of the channels are actually set
+		 * up but let UBSAN know the boundaries.
+		 */
+		local->hw_scan_req->req.n_channels = req->n_channels;
+
 		ies = (u8 *)local->hw_scan_req +
 			sizeof(*local->hw_scan_req) +
 			req->n_channels * sizeof(req->channels[0]);