File expat-CVE-2024-45491.patch of Package expat.36378

From 8e439a9947e9dc80a395c0c7456545d8d9d9e421 Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <sebastian@pipping.org>
Date: Mon, 19 Aug 2024 22:34:13 +0200
Subject: [PATCH] lib: Detect integer overflow in dtdCopy

Reported by TaiYou
---
 expat/lib/xmlparse.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Index: expat-2.2.5/lib/xmlparse.c
===================================================================
--- expat-2.2.5.orig/lib/xmlparse.c
+++ expat-2.2.5/lib/xmlparse.c
@@ -6806,6 +6806,16 @@ dtdCopy(XML_Parser oldParser, DTD *newDt
     if (!newE)
       return 0;
     if (oldE->nDefaultAtts) {
+      /* Detect and prevent integer overflow.
+       * The preprocessor guard addresses the "always false" warning
+       * from -Wtype-limits on platforms where
+       * sizeof(int) < sizeof(size_t), e.g. on x86_64. */
+#if UINT_MAX >= SIZE_MAX
+      if ((size_t)oldE->nDefaultAtts
+          > ((size_t)(-1) / sizeof(DEFAULT_ATTRIBUTE))) {
+        return 0;
+      }
+#endif
       newE->defaultAtts = (DEFAULT_ATTRIBUTE *)
           ms->malloc_fcn(oldE->nDefaultAtts * sizeof(DEFAULT_ATTRIBUTE));
       if (!newE->defaultAtts) {