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;
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<div class='path'>path: <a href='/guix/log/?id=3dd310087a883df6eb5ce47ca24fe8fbac15a2d7'>root</a>/<a href='/guix/log/gnu?id=3dd310087a883df6eb5ce47ca24fe8fbac15a2d7'>gnu</a>/<a href='/guix/log/gnu/packages?id=3dd310087a883df6eb5ce47ca24fe8fbac15a2d7'>packages</a>/<a href='/guix/log/gnu/packages/stb.scm?id=3dd310087a883df6eb5ce47ca24fe8fbac15a2d7'>stb.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/stb.scm?id=3dd310087a883df6eb5ce47ca24fe8fbac15a2d7&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-02-05 00:21:27 +0100'>2020-02-05</span></td><td><a href='/guix/commit/gnu/packages/stb.scm?id=6e43e1eee8b6ecf567686885e4707f889643b55b'>gnu: Add stb-truetype.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/stb.scm (stb-truetype): New variable.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Giacomo Leidi</td></tr>
<tr><td><span title='2020-02-05 00:21:27 +0100'>2020-02-05</span></td><td><a href='/guix/commit/gnu/packages/stb.scm?id=8a4c7be4c80b2bbc20885d9cad5534fdda290368'>gnu: Add stb-sprintf.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/stb.scm (stb-sprintf): New variable.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Giacomo Leidi</td></tr>