From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Sadaf Ebrahimi <sadafebrahimi@google.com>
Date: Fri, 3 Jun 2022 03:40:21 +0000
Subject: [PATCH] Prevent integer overflow in function doProlog
Bug: http://b/221256678
Change-Id: I6fe381103f4eb287726d1ccb5bfec99db160ffe4
(cherry picked from commit 257f1d3777240016d3ccd74a61cd7d0e0efcaae3)
Merged-In: I6fe381103f4eb287726d1ccb5bfec99db160ffe4
---
lib/xmlparse.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/lib/xmlparse.c b/lib/xmlparse.c
index 91f50034..0e57538a 100644
--- a/lib/xmlparse.c
+++ b/lib/xmlparse.c
@@ -4671,23 +4671,29 @@ doProlog(XML_Parser parser,
if (dtd->in_eldecl) {
ELEMENT_TYPE *el;
const XML_Char *name;
- int nameLen;
- const char *nxt = (quant == XML_CQUANT_NONE
- ? next
- : next - enc->minBytesPerChar);
+ size_t nameLen;
+ const char *nxt
+ = (quant == XML_CQUANT_NONE ? next : next - enc->minBytesPerChar);
int myindex = nextScaffoldPart(parser);
if (myindex < 0)
return XML_ERROR_NO_MEMORY;
dtd->scaffold[myindex].type = XML_CTYPE_NAME;
dtd->scaffold[myindex].quant = quant;
el = getElementType(parser, enc, s, nxt);
- if (!el)
+ if (! el)
return XML_ERROR_NO_MEMORY;
name = el->name;
dtd->scaffold[myindex].name = name;
nameLen = 0;
- for (; name[nameLen++]; );
- dtd->contentStringLen += nameLen;
+ for (; name[nameLen++];)
+ ;
+
+ /* Detect and prevent integer overflow */
+ if (nameLen > UINT_MAX - dtd->contentStringLen) {
+ return XML_ERROR_NO_MEMORY;
+ }
+
+ dtd->contentStringLen += (unsigned)nameLen;
if (elementDeclHandler)
handleDefault = XML_FALSE;
}