gnu: expat: Fix security vulnerabilities.

Fixes CVE-2024-45490, CVE-2024-45491, CVE-2024-45492.

* gnu/packages/xml.scm (expat)[replacement]: New field.
(expat/fixed): New variable.
* gnu/packages/patches/expat-CVE-2024-45490.patch,
gnu/packages/patches/expat-CVE-2024-45491.patch,
gnu/packages/patches/expat-CVE-2024-45492.patch: New files.
* gnu/local.mk (dist_patch_DATA): Register them.

Change-Id: I74d5d7bce98d6c983b989c1afec7cf28777d1617

1 files changed, 33 insertions, 0 deletions

diff --git a/gnu/packages/patches/expat-CVE-2024-45492.patch b/gnu/packages/patches/expat-CVE-2024-45492.patch
new file mode 100644
index 0000000000..852a9b3f59
--- /dev/null
+++ b/gnu/packages/patches/expat-CVE-2024-45492.patch
@@ -0,0 +1,33 @@
+https://github.com/libexpat/libexpat/commit/9bf0f2c16ee86f644dd1432507edff94c08dc232.patch
+Fixed in 2.6.3.
+
+From 9bf0f2c16ee86f644dd1432507edff94c08dc232 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
+---
+ expat/lib/xmlparse.c | 9 +++++++++
+ 1 file changed, 9 insertions(+)
+
+diff --git a/lib/xmlparse.c b/lib/xmlparse.c
+index 91682c188..f737575ea 100644
+--- a/lib/xmlparse.c
++++ b/lib/xmlparse.c
+@@ -7558,6 +7558,15 @@ 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;