expat: fix CVE-2024-45492

An issue was discovered in libexpat before 2.6.3. nextScaffoldPart in xmlparse.c can have
an integer overflow for m_groupSize on 32-bit platforms (where UINT_MAX equals SIZE_MAX).

(From OE-Core rev: 5b31e7f46ab05aca48f4fb11c558ff990e772c9e)

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-core/expat/expat/CVE-2024-45492.patch

@@ -0,0 +1,38 @@
+From 9b0615959a4df00b4719c5beae286eb52fd32fe0 Mon Sep 17 00:00:00 2001
+From: Sebastian Pipping <sebastian@pipping.org>
+Date: Mon, 19 Aug 2024 22:37:16 +0200
+Subject: [PATCH] lib: Detect integer overflow in function nextScaffoldPart
+
+Reported by TaiYou
+
+CVE: CVE-2024-45492
+
+Upstream-Status: Backport [https://github.com/libexpat/libexpat/pull/892/commits/9bf0f2c16ee86f64]
+
+Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
+---
+ lib/xmlparse.c | 9 +++++++++
+ 1 file changed, 9 insertions(+)
+
+diff --git a/lib/xmlparse.c b/lib/xmlparse.c
+index adb27e3..6d7e92f 100644
+--- a/lib/xmlparse.c
++++ b/lib/xmlparse.c
+@@ -7465,6 +7465,15 @@ nextScaffoldPart(XML_Parser parser) {
+   int next;
+
+   if (! dtd->scaffIndex) {
++    /* Detect and prevent integer overflow.
++     * The preprocessor guard addresses the "always false" warning
++     * from -Wtype-limits on platforms where
++     * sizeof(unsigned int) < sizeof(size_t), e.g. on x86_64. */
++#if UINT_MAX >= SIZE_MAX
++    if (parser->m_groupSize > ((size_t)(-1) / sizeof(int))) {
++      return -1;
++    }
++#endif
+     dtd->scaffIndex = (int *)MALLOC(parser, parser->m_groupSize * sizeof(int));
+     if (! dtd->scaffIndex)
+       return -1;
+--
+2.40.0

meta/recipes-core/expat/expat_2.5.0.bb

@@ -27,6 +27,7 @@ SRC_URI = "https://github.com/libexpat/libexpat/releases/download/R_${VERSION_TA
 	   file://CVE-2024-45490-0003.patch \
 	   file://CVE-2024-45490-0004.patch \
 	   file://CVE-2024-45491.patch \
+	   file://CVE-2024-45492.patch \
            "
 
 UPSTREAM_CHECK_URI = "https://github.com/libexpat/libexpat/releases/"