fix CVE-2022-29824

This commit is contained in:
fuanan 2022-05-09 09:27:00 +08:00
parent afea9c32b6
commit b3c3367374
2 changed files with 349 additions and 1 deletions

View File

@ -0,0 +1,341 @@
From 2554a2408e09f13652049e5ffb0d26196b02ebab Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Tue, 8 Mar 2022 20:10:02 +0100
Subject: [PATCH] [CVE-2022-29824] Fix integer overflows in xmlBuf and
xmlBuffer
In several places, the code handling string buffers didn't check for
integer overflow or used wrong types for buffer sizes. This could
result in out-of-bounds writes or other memory errors when working on
large, multi-gigabyte buffers.
Thanks to Felix Wilhelm for the report.
---
buf.c | 86 +++++++++++++++++++++++-----------------------------------
tree.c | 72 ++++++++++++++++++------------------------------
2 files changed, 61 insertions(+), 97 deletions(-)
diff --git a/buf.c b/buf.c
index 24368d37..40a5ee06 100644
--- a/buf.c
+++ b/buf.c
@@ -30,6 +30,10 @@
#include <libxml/parserInternals.h> /* for XML_MAX_TEXT_LENGTH */
#include "buf.h"
+#ifndef SIZE_MAX
+#define SIZE_MAX ((size_t) -1)
+#endif
+
#define WITH_BUFFER_COMPAT
/**
@@ -156,6 +160,8 @@ xmlBufPtr
xmlBufCreateSize(size_t size) {
xmlBufPtr ret;
+ if (size == SIZE_MAX)
+ return(NULL);
ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf));
if (ret == NULL) {
xmlBufMemoryError(NULL, "creating buffer");
@@ -166,8 +172,8 @@ xmlBufCreateSize(size_t size) {
ret->error = 0;
ret->buffer = NULL;
ret->alloc = xmlBufferAllocScheme;
- ret->size = (size ? size+2 : 0); /* +1 for ending null */
- ret->compat_size = (int) ret->size;
+ ret->size = (size ? size + 1 : 0); /* +1 for ending null */
+ ret->compat_size = (ret->size > INT_MAX ? INT_MAX : ret->size);
if (ret->size){
ret->content = (xmlChar *) xmlMallocAtomic(ret->size * sizeof(xmlChar));
if (ret->content == NULL) {
@@ -442,23 +448,17 @@ xmlBufGrowInternal(xmlBufPtr buf, size_t len) {
CHECK_COMPAT(buf)
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0);
- if (buf->use + len < buf->size)
+ if (len < buf->size - buf->use)
return(buf->size - buf->use);
+ if (len > SIZE_MAX - buf->use)
+ return(0);
- /*
- * Windows has a BIG problem on realloc timing, so we try to double
- * the buffer size (if that's enough) (bug 146697)
- * Apparently BSD too, and it's probably best for linux too
- * On an embedded system this may be something to change
- */
-#if 1
- if (buf->size > (size_t) len)
- size = buf->size * 2;
- else
- size = buf->use + len + 100;
-#else
- size = buf->use + len + 100;
-#endif
+ if (buf->size > (size_t) len) {
+ size = buf->size > SIZE_MAX / 2 ? SIZE_MAX : buf->size * 2;
+ } else {
+ size = buf->use + len;
+ size = size > SIZE_MAX - 100 ? SIZE_MAX : size + 100;
+ }
if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
/*
@@ -744,7 +744,7 @@ xmlBufIsEmpty(const xmlBufPtr buf)
int
xmlBufResize(xmlBufPtr buf, size_t size)
{
- unsigned int newSize;
+ size_t newSize;
xmlChar* rebuf = NULL;
size_t start_buf;
@@ -772,9 +772,13 @@ xmlBufResize(xmlBufPtr buf, size_t size)
case XML_BUFFER_ALLOC_IO:
case XML_BUFFER_ALLOC_DOUBLEIT:
/*take care of empty case*/
- newSize = (buf->size ? buf->size*2 : size + 10);
+ if (buf->size == 0) {
+ newSize = (size > SIZE_MAX - 10 ? SIZE_MAX : size + 10);
+ } else {
+ newSize = buf->size;
+ }
while (size > newSize) {
- if (newSize > UINT_MAX / 2) {
+ if (newSize > SIZE_MAX / 2) {
xmlBufMemoryError(buf, "growing buffer");
return 0;
}
@@ -782,15 +786,15 @@ xmlBufResize(xmlBufPtr buf, size_t size)
}
break;
case XML_BUFFER_ALLOC_EXACT:
- newSize = size+10;
+ newSize = (size > SIZE_MAX - 10 ? SIZE_MAX : size + 10);
break;
case XML_BUFFER_ALLOC_HYBRID:
if (buf->use < BASE_BUFFER_SIZE)
newSize = size;
else {
- newSize = buf->size * 2;
+ newSize = buf->size;
while (size > newSize) {
- if (newSize > UINT_MAX / 2) {
+ if (newSize > SIZE_MAX / 2) {
xmlBufMemoryError(buf, "growing buffer");
return 0;
}
@@ -800,7 +804,7 @@ xmlBufResize(xmlBufPtr buf, size_t size)
break;
default:
- newSize = size+10;
+ newSize = (size > SIZE_MAX - 10 ? SIZE_MAX : size + 10);
break;
}
@@ -866,7 +870,7 @@ xmlBufResize(xmlBufPtr buf, size_t size)
*/
int
xmlBufAdd(xmlBufPtr buf, const xmlChar *str, int len) {
- unsigned int needSize;
+ size_t needSize;
if ((str == NULL) || (buf == NULL) || (buf->error))
return -1;
@@ -888,8 +892,10 @@ xmlBufAdd(xmlBufPtr buf, const xmlChar *str, int len) {
if (len < 0) return -1;
if (len == 0) return 0;
- needSize = buf->use + len + 2;
- if (needSize > buf->size){
+ if ((size_t) len >= buf->size - buf->use) {
+ if ((size_t) len >= SIZE_MAX - buf->use)
+ return(-1);
+ needSize = buf->use + len + 1;
if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
/*
* Used to provide parsing limits
@@ -1025,31 +1031,7 @@ xmlBufCat(xmlBufPtr buf, const xmlChar *str) {
*/
int
xmlBufCCat(xmlBufPtr buf, const char *str) {
- const char *cur;
-
- if ((buf == NULL) || (buf->error))
- return(-1);
- CHECK_COMPAT(buf)
- if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1;
- if (str == NULL) {
-#ifdef DEBUG_BUFFER
- xmlGenericError(xmlGenericErrorContext,
- "xmlBufCCat: str == NULL\n");
-#endif
- return -1;
- }
- for (cur = str;*cur != 0;cur++) {
- if (buf->use + 10 >= buf->size) {
- if (!xmlBufResize(buf, buf->use+10)){
- xmlBufMemoryError(buf, "growing buffer");
- return XML_ERR_NO_MEMORY;
- }
- }
- buf->content[buf->use++] = *cur;
- }
- buf->content[buf->use] = 0;
- UPDATE_COMPAT(buf)
- return 0;
+ return xmlBufCat(buf, (const xmlChar *) str);
}
/**
diff --git a/tree.c b/tree.c
index 9d94aa42..86afb7d6 100644
--- a/tree.c
+++ b/tree.c
@@ -7104,6 +7104,8 @@ xmlBufferPtr
xmlBufferCreateSize(size_t size) {
xmlBufferPtr ret;
+ if (size >= UINT_MAX)
+ return(NULL);
ret = (xmlBufferPtr) xmlMalloc(sizeof(xmlBuffer));
if (ret == NULL) {
xmlTreeErrMemory("creating buffer");
@@ -7111,7 +7113,7 @@ xmlBufferCreateSize(size_t size) {
}
ret->use = 0;
ret->alloc = xmlBufferAllocScheme;
- ret->size = (size ? size+2 : 0); /* +1 for ending null */
+ ret->size = (size ? size + 1 : 0); /* +1 for ending null */
if (ret->size){
ret->content = (xmlChar *) xmlMallocAtomic(ret->size * sizeof(xmlChar));
if (ret->content == NULL) {
@@ -7171,6 +7173,8 @@ xmlBufferCreateStatic(void *mem, size_t size) {
if ((mem == NULL) || (size == 0))
return(NULL);
+ if (size > UINT_MAX)
+ return(NULL);
ret = (xmlBufferPtr) xmlMalloc(sizeof(xmlBuffer));
if (ret == NULL) {
@@ -7318,28 +7322,23 @@ xmlBufferShrink(xmlBufferPtr buf, unsigned int len) {
*/
int
xmlBufferGrow(xmlBufferPtr buf, unsigned int len) {
- int size;
+ unsigned int size;
xmlChar *newbuf;
if (buf == NULL) return(-1);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0);
- if (len + buf->use < buf->size) return(0);
+ if (len < buf->size - buf->use)
+ return(0);
+ if (len > UINT_MAX - buf->use)
+ return(-1);
- /*
- * Windows has a BIG problem on realloc timing, so we try to double
- * the buffer size (if that's enough) (bug 146697)
- * Apparently BSD too, and it's probably best for linux too
- * On an embedded system this may be something to change
- */
-#if 1
- if (buf->size > len)
- size = buf->size * 2;
- else
- size = buf->use + len + 100;
-#else
- size = buf->use + len + 100;
-#endif
+ if (buf->size > (size_t) len) {
+ size = buf->size > UINT_MAX / 2 ? UINT_MAX : buf->size * 2;
+ } else {
+ size = buf->use + len;
+ size = size > UINT_MAX - 100 ? UINT_MAX : size + 100;
+ }
if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) {
size_t start_buf = buf->content - buf->contentIO;
@@ -7466,7 +7465,10 @@ xmlBufferResize(xmlBufferPtr buf, unsigned int size)
case XML_BUFFER_ALLOC_IO:
case XML_BUFFER_ALLOC_DOUBLEIT:
/*take care of empty case*/
- newSize = (buf->size ? buf->size : size + 10);
+ if (buf->size == 0)
+ newSize = (size > UINT_MAX - 10 ? UINT_MAX : size + 10);
+ else
+ newSize = buf->size;
while (size > newSize) {
if (newSize > UINT_MAX / 2) {
xmlTreeErrMemory("growing buffer");
@@ -7476,7 +7478,7 @@ xmlBufferResize(xmlBufferPtr buf, unsigned int size)
}
break;
case XML_BUFFER_ALLOC_EXACT:
- newSize = size+10;
+ newSize = (size > UINT_MAX - 10 ? UINT_MAX : size + 10);;
break;
case XML_BUFFER_ALLOC_HYBRID:
if (buf->use < BASE_BUFFER_SIZE)
@@ -7494,7 +7496,7 @@ xmlBufferResize(xmlBufferPtr buf, unsigned int size)
break;
default:
- newSize = size+10;
+ newSize = (size > UINT_MAX - 10 ? UINT_MAX : size + 10);;
break;
}
@@ -7580,8 +7582,10 @@ xmlBufferAdd(xmlBufferPtr buf, const xmlChar *str, int len) {
if (len < 0) return -1;
if (len == 0) return 0;
- needSize = buf->use + len + 2;
- if (needSize > buf->size){
+ if ((unsigned) len >= buf->size - buf->use) {
+ if ((unsigned) len >= UINT_MAX - buf->use)
+ return XML_ERR_NO_MEMORY;
+ needSize = buf->use + len + 1;
if (!xmlBufferResize(buf, needSize)){
xmlTreeErrMemory("growing buffer");
return XML_ERR_NO_MEMORY;
@@ -7694,29 +7698,7 @@ xmlBufferCat(xmlBufferPtr buf, const xmlChar *str) {
*/
int
xmlBufferCCat(xmlBufferPtr buf, const char *str) {
- const char *cur;
-
- if (buf == NULL)
- return(-1);
- if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1;
- if (str == NULL) {
-#ifdef DEBUG_BUFFER
- xmlGenericError(xmlGenericErrorContext,
- "xmlBufferCCat: str == NULL\n");
-#endif
- return -1;
- }
- for (cur = str;*cur != 0;cur++) {
- if (buf->use + 10 >= buf->size) {
- if (!xmlBufferResize(buf, buf->use+10)){
- xmlTreeErrMemory("growing buffer");
- return XML_ERR_NO_MEMORY;
- }
- }
- buf->content[buf->use++] = *cur;
- }
- buf->content[buf->use] = 0;
- return 0;
+ return xmlBufferCat(buf, (const xmlChar *) str);
}
/**
--
GitLab

View File

@ -1,7 +1,7 @@
Summary: Library providing XML and HTML support
Name: libxml2
Version: 2.9.12
Release: 5
Release: 6
License: MIT
Group: Development/Libraries
Source: ftp://xmlsoft.org/libxml2/libxml2-%{version}.tar.gz
@ -17,6 +17,7 @@ Patch7: Fix-whitespace-when-serializing-empty-HTML-documents.patch
Patch8: Patch-to-forbid-epsilon-reduction-of-final-states.patch
Patch9: Fix-buffering-in-xmlOutputBufferWrite.patch
Patch10:backport-CVE-2022-23308-Use-after-free-of-ID-and-IDREF-attrib.patch
Patch11:backport-CVE-2022-29824-Fix-integer-overflows-in-xmlBuf-and-xmlBuffer.patch
BuildRoot: %{_tmppath}/%{name}-%{version}-root
BuildRequires: python3-devel
@ -177,6 +178,12 @@ rm -fr %{buildroot}
%changelog
* Mon May 09 2022 fuanan <fuanan3@h-partners.com> - 2.9.12-6
- Type:CVE
- ID:CVE-2022-29824
- SUG:NA
- DESC:fix CVE-2022-29824
* Wed Mar 09 2022 fuanan <fuanan3@h-partners.com> - 2.9.12-5
- Type:CVE
- ID:CVE-2022-23308