wl1251: Fix possible buffer overflow in wl1251_cmd_scan

[ Upstream commit d10a87a ]

Function wl1251_cmd_scan calls memcpy without checking the length.
Harden by checking the length is within the maximum allowed size.

Signed-off-by: Lee Gibson <leegib@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210428115508.25624-1-leegib@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/wireless/ti/wl1251/cmd.c

@@ -465,9 +465,12 @@ int wl1251_cmd_scan(struct wl1251 *wl, u8 *ssid, size_t ssid_len,
 		cmd->channels[i].channel = channels[i]->hw_value;
 	}
 
-	cmd->params.ssid_len = ssid_len;
-	if (ssid)
-		memcpy(cmd->params.ssid, ssid, ssid_len);
+	if (ssid) {
+		int len = clamp_val(ssid_len, 0, IEEE80211_MAX_SSID_LEN);
+
+		cmd->params.ssid_len = len;
+		memcpy(cmd->params.ssid, ssid, len);
+	}
 
 	ret = wl1251_cmd_send(wl, CMD_SCAN, cmd, sizeof(*cmd));
 	if (ret < 0) {