CVE-2022-23990 expat: integer overflow in the doProlog function

Resolve: rhbz#2050503

expat-2.2.10-prevent-integer-overflow-in-doProlog.patch

@@ -0,0 +1,42 @@
+From ede41d1e186ed2aba88a06e84cac839b770af3a1 Mon Sep 17 00:00:00 2001
+From: Sebastian Pipping <sebastian@pipping.org>
+Date: Wed, 26 Jan 2022 02:36:43 +0100
+Subject: [PATCH 1/2] lib: Prevent integer overflow in doProlog
+ (CVE-2022-23990)
+
+The change from "int nameLen" to "size_t nameLen"
+addresses the overflow on "nameLen++" in code
+"for (; name[nameLen++];)" right above the second
+change in the patch.
+---
+ expat/lib/xmlparse.c | 10 ++++++++--
+ 1 file changed, 8 insertions(+), 2 deletions(-)
+
+diff --git a/lib/xmlparse.c b/lib/xmlparse.c
+index 5ce31402..d1d17005 100644
+--- a/lib/xmlparse.c
++++ b/lib/xmlparse.c
+@@ -5372,7 +5372,7 @@ doProlog(XML_Parser parser, const ENCODING *enc, const char *s, const char *end,
+       if (dtd->in_eldecl) {
+         ELEMENT_TYPE *el;
+         const XML_Char *name;
+-        int nameLen;
++        size_t nameLen;
+         const char *nxt
+             = (quant == XML_CQUANT_NONE ? next : next - enc->minBytesPerChar);
+         int myindex = nextScaffoldPart(parser);
+@@ -5388,7 +5388,13 @@ doProlog(XML_Parser parser, const ENCODING *enc, const char *s, const char *end,
+         nameLen = 0;
+         for (; name[nameLen++];)
+           ;
+-        dtd->contentStringLen += nameLen;
++
++        /* Detect and prevent integer overflow */
++        if (nameLen > UINT_MAX - dtd->contentStringLen) {
++          return XML_ERROR_NO_MEMORY;
++        }
++
++        dtd->contentStringLen += (unsigned)nameLen;
+         if (parser->m_elementDeclHandler)
+           handleDefault = XML_FALSE;
+       }

expat-2.2.3-fixtests.patch

@@ -1,14 +0,0 @@
-
-https://github.com/libexpat/libexpat/pull/109
-
---- libexpat-R_2_2_3/expat/tests/runtests.c.fixtests
-+++ libexpat-R_2_2_3/expat/tests/runtests.c
-@@ -5671,7 +5671,7 @@ static int XMLCALL
- prefix_converter(void *UNUSED_P(data), const char *s)
- {
-     /* If the first byte is 0xff, raise an error */
--    if (s[0] == -1)
-+    if (s[0] == (char)-1)
-         return -1;
-     /* Just add the low bits of the first byte to the second */
-     return (s[1] + (s[0] & 0x7f)) & 0x01ff;

expat.spec

@@ -3,12 +3,13 @@
 Summary: An XML parser library
 Name: expat
 Version: %(echo %{unversion} | sed 's/_/./g')
-Release: 4%{?dist}
+Release: 5%{?dist}
 Source: https://github.com/libexpat/libexpat/archive/R_%{unversion}.tar.gz#/expat-%{version}.tar.gz
 URL: https://libexpat.github.io/
 License: MIT
 BuildRequires: autoconf, libtool, xmlto, gcc-c++
 BuildRequires: make
+Patch0:	expat-2.2.10-prevent-integer-overflow-in-doProlog.patch
 
 %description
 This is expat, the C library for parsing XML, written by James Clark. Expat
@@ -36,6 +37,7 @@ Install it if you need to link statically with expat.
 
 %prep
 %setup -q -n libexpat-R_%{unversion}/expat
+%patch0 -p1 -b .CVE-2022-23990
 sed -i 's/install-data-hook/do-nothing-please/' lib/Makefile.am
 ./buildconf.sh
 
@@ -72,6 +74,10 @@ make check
 %{_libdir}/lib*.a
 
 %changelog
+* Mon Feb 07 2022 Tomas Korbar <tkorbar@redhat.com> -  2.2.10-5
+- CVE-2022-23990 expat: integer overflow in the doProlog function
+- Resolve: rhbz#2050503
+
 * Mon Aug 09 2021 Mohan Boddu <mboddu@redhat.com> - 2.2.10-4
 - Rebuilt for IMA sigs, glibc 2.34, aarch64 flags
   Related: rhbz#1991688