File expat-CVE-2022-22823.patch of Package expat.22462

From 9f93e8036e842329863bf20395b8fb8f73834d9e Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <sebastian@pipping.org>
Date: Thu, 30 Dec 2021 22:46:03 +0100
Subject: [PATCH] lib: Prevent integer overflow at multiple places
 (CVE-2022-22822 to CVE-2022-22827)

The involved functions are:
- addBinding (CVE-2022-22822)
- build_model (CVE-2022-22823)
- defineAttribute (CVE-2022-22824)
- lookup (CVE-2022-22825)
- nextScaffoldPart (CVE-2022-22826)
- storeAtts (CVE-2022-22827)
---
 expat/lib/xmlparse.c | 153 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 151 insertions(+), 2 deletions(-)

Index: expat-2.2.5/lib/xmlparse.c
===================================================================
--- expat-2.2.5.orig/lib/xmlparse.c
+++ expat-2.2.5/lib/xmlparse.c
@@ -7214,8 +7214,26 @@ build_model (XML_Parser parser)
   XML_Content *ret;
   XML_Content *cpos;
   XML_Char * str;
-  int allocsize = (dtd->scaffCount * sizeof(XML_Content)
-                   + (dtd->contentStringLen * sizeof(XML_Char)));
+
+  /* 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 (dtd->scaffCount > (size_t)(-1) / sizeof(XML_Content)) {
+    return NULL;
+  }
+  if (dtd->contentStringLen > (size_t)(-1) / sizeof(XML_Char)) {
+    return NULL;
+  }
+#endif
+  if (dtd->scaffCount * sizeof(XML_Content)
+      > (size_t)(-1) - dtd->contentStringLen * sizeof(XML_Char)) {
+    return NULL;
+  }
+
+  const size_t allocsize = (dtd->scaffCount * sizeof(XML_Content)
+                            + (dtd->contentStringLen * sizeof(XML_Char)));
 
   ret = (XML_Content *)MALLOC(parser, allocsize);
   if (!ret)
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