commit 75bb51c072a0a505037bea18d18103473000b339
Author: Tomas Korbar <tkorbar@redhat.com>
Date:   Wed Sep 11 15:07:26 2024 +0200

    Fix CVE-2024-45491
    
    https://github.com/libexpat/libexpat/pull/891

diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
index c3c1af9..6818c4e 100644
--- a/expat/lib/xmlparse.c
+++ b/expat/lib/xmlparse.c
@@ -6843,6 +6843,16 @@ dtdCopy(XML_Parser oldParser, DTD *newDtd, const DTD *oldDtd, const XML_Memory_H
     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) {