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=503998ac7ae16bf5587c69db18e70abdd2f14565'>root</a>/<a href='/guix/log/guix.scm?id=503998ac7ae16bf5587c69db18e70abdd2f14565'>guix.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/guix.scm?id=503998ac7ae16bf5587c69db18e70abdd2f14565&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-07-12 01:17:45 +0200'>2022-07-12</span></td><td><a href='/guix/commit/guix.scm?id=4574ef267e543bcac97d9c400f30cb731df29181'>guix: Really export 'define-public'.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to 3858275962f1ac567b5dce2355035f9eddea0a05, which
didn't have any effect.

* guix.scm: Explicitly use (guix packages) so #:re-export-and-replace
is effective.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-09-14 11:50:58 +0200'>2021-09-14</span></td><td><a href='/guix/commit/guix.scm?id=3858275962f1ac567b5dce2355035f9eddea0a05'>guix: Replace 'define-public'.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to 8531997d2a1e10d574a6e9ab70bc86ade6af4733.

* guix.scm: Use #:re-export-and-replace for 'define-public'.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-06-29 00:00:13 +0200'>2021-06-29</span></td><td><a href='/guix/commit/guix.scm?id=e059adcb6001ab0353d969b24030d0c342f8830e'>(guix) no longer pulls in (guix ftp-client).</a><span class='msg-avail'>...<span class='msg-tooltip'>That choice was made in 2014 and never made much sense.

* guix.scm (%public-modules): Remove 'ftp-client'.
</span></span></td><td>Ludovic Courtès</td></tr>