1From ede41d1e186ed2aba88a06e84cac839b770af3a1 Mon Sep 17 00:00:00 2001 2From: Sebastian Pipping <sebastian@pipping.org> 3Date: Wed, 26 Jan 2022 02:36:43 +0100 4Subject: [PATCH] lib: Prevent integer overflow in doProlog 5 (CVE-2022-23990) 6 7The change from "int nameLen" to "size_t nameLen" 8addresses the overflow on "nameLen++" in code 9"for (; name[nameLen++];)" right above the second 10change in the patch. 11--- 12 lib/xmlparse.c | 10 ++++++++-- 13 1 file changed, 8 insertions(+), 2 deletions(-) 14 15diff --git a/lib/xmlparse.c b/lib/xmlparse.c 16index 5ce3140..d1d1700 100644 17--- a/lib/xmlparse.c 18+++ b/lib/xmlparse.c 19@@ -5372,7 +5372,7 @@ doProlog(XML_Parser parser, const ENCODING *enc, const char *s, const char *end, 20 if (dtd->in_eldecl) { 21 ELEMENT_TYPE *el; 22 const XML_Char *name; 23- int nameLen; 24+ size_t nameLen; 25 const char *nxt 26 = (quant == XML_CQUANT_NONE ? next : next - enc->minBytesPerChar); 27 int myindex = nextScaffoldPart(parser); 28@@ -5388,7 +5388,13 @@ doProlog(XML_Parser parser, const ENCODING *enc, const char *s, const char *end, 29 nameLen = 0; 30 for (; name[nameLen++];) 31 ; 32- dtd->contentStringLen += nameLen; 33+ 34+ /* Detect and prevent integer overflow */ 35+ if (nameLen > UINT_MAX - dtd->contentStringLen) { 36+ return XML_ERROR_NO_MEMORY; 37+ } 38+ 39+ dtd->contentStringLen += (unsigned)nameLen; 40 if (parser->m_elementDeclHandler) 41 handleDefault = XML_FALSE; 42 } 43-- 441.8.3.1 45 46