From 7d0a920d34e9960b2dd2e3583172826b3a4db570 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matej=20Mu=C5=BEila?= <mmuzila@redhat.com>
Date: Tue, 8 Aug 2023 15:32:42 +0200
Subject: [PATCH] (CVE-2023-26966) tif_luv: Check and correct for NaN data in
 uv_encode().

Closes #530

See merge request libtiff/libtiff!473

(cherry picked from commit d1f658afa5ab5ed21a9e32e0f790f41b01506cd9)
---
 libtiff/tif_luv.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/libtiff/tif_luv.c b/libtiff/tif_luv.c
index 72ab3668..93c76115 100644
--- a/libtiff/tif_luv.c
+++ b/libtiff/tif_luv.c
@@ -908,7 +908,14 @@ uv_encode(double u, double v, int em)	/* encode (u',v') coordinates */
 {
 	register int	vi, ui;
 
-	if (v < UV_VSTART)
+    /* check for NaN */
+    if (u != u || v != v)
+    {
+        u = U_NEU;
+        v = V_NEU;
+    }
+
+    if (v < UV_VSTART)
 		return oog_encode(u, v);
 	vi = tiff_itrunc((v - UV_VSTART)*(1./UV_SQSIZ), em);
 	if (vi >= UV_NVS)