diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
index 14482c26c0a7..4bb72e32f661 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
@@ -263,6 +263,13 @@ dw_hdmi_rockchip_mode_valid(struct dw_hdmi *hdmi, void *data,
 			break;
 		}
 	}
+	/*
+	 * Pixel clocks we support are always < 2GHz and so fit in an
+	 * int.  We should make sure source rate does too so we don't get
+	 * overflow when we multiply by 1000.
+	 */
+	if (mode->clock > INT_MAX / 1000)
+		return MODE_BAD;
 
 	return (valid) ? MODE_OK : MODE_BAD;
 }