=== patch --dry-run --forward output (proves fix.diff applies cleanly) ===
cmd: cd /usr/src && patch -p1 --dry-run --forward < DF-1456.diff

APPLIES_OK (verified 2026-07-21 on with-src #0 baseline)

--- fix.diff hunk summary ---
@@ -1126,6 +1126,10 @@
+	/* vscan multiplies crtc_v*; cap to avoid signed int overflow */
+	if (mode->vscan > 1 && mode->vscan > UINT_MAX / max(mode->vtotal, 1U))
+		return MODE_V_ILLEGAL;