From 0cb3d4d101334a2b8728f810dd14e71af62c2dc9 Mon Sep 17 00:00:00 2001
From: lvfei <lvfei@kylinos.cn>
Date: Thu, 20 Jul 2023 15:11:53 +0800
Subject: [PATCH] CVE-2021-46143

---
 parser/expat/lib/xmlparse.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/parser/expat/lib/xmlparse.c b/parser/expat/lib/xmlparse.c
index f81a68d2fc..d087eb48da 100644
--- a/parser/expat/lib/xmlparse.c
+++ b/parser/expat/lib/xmlparse.c
@@ -5046,11 +5046,26 @@ doProlog(XML_Parser parser,
     case XML_ROLE_GROUP_OPEN:
       if (prologState.level >= groupSize) {
         if (groupSize) {
+
+          /* Detect and prevent integer overflow */
+          if (parser->m_groupSize > (unsigned int)(-1) / 2u) {
+            return XML_ERROR_NO_MEMORY;
+          }
+
           char *temp = (char *)REALLOC(groupConnector, groupSize *= 2);
           if (temp == NULL)
             return XML_ERROR_NO_MEMORY;
           groupConnector = temp;
           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 XML_ERROR_NO_MEMORY;
+            }
+#endif
             int *temp = (int *)REALLOC(dtd->scaffIndex,
                           groupSize * sizeof(int));
             if (temp == NULL)
-- 
2.27.0