libxml2: Security Advisory - libxml2 - CVE-2015-1819

for CVE-2015-1819 Enforce the reader to run in constant memory

(From OE-Core rev: 9e67d8ae592a37d7c92d6566466b09c83e9ec6a7)

Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
Signed-off-by: Wenzong Fan <wenzong.fan@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 182 insertions, 0 deletions

diff --git a/meta/recipes-core/libxml/libxml2.inc b/meta/recipes-core/libxml/libxml2.inc
index d337bec0d0..1c3c37d509 100644
--- a/meta/recipes-core/libxml/libxml2.inc
+++ b/meta/recipes-core/libxml/libxml2.inc
@@ -20,6 +20,7 @@ SRC_URI = "ftp://xmlsoft.org/libxml2/libxml2-${PV}.tar.gz;name=libtar \
            file://python-sitepackages-dir.patch \
            file://libxml-m4-use-pkgconfig.patch \
            file://configure.ac-fix-cross-compiling-warning.patch \
+           file://0001-CVE-2015-1819-Enforce-the-reader-to-run-in-constant-.patch \
           "
 
 BINCONFIG = "${bindir}/xml2-config"
diff --git a/meta/recipes-core/libxml/libxml2/0001-CVE-2015-1819-Enforce-the-reader-to-run-in-constant-.patch b/meta/recipes-core/libxml/libxml2/0001-CVE-2015-1819-Enforce-the-reader-to-run-in-constant-.patch
new file mode 100644
index 0000000000..96d58f9dd6
--- /dev/null
+++ b/meta/recipes-core/libxml/libxml2/0001-CVE-2015-1819-Enforce-the-reader-to-run-in-constant-.patch
@@ -0,0 +1,181 @@
+From 213f1fe0d76d30eaed6e5853057defc43e6df2c9 Mon Sep 17 00:00:00 2001
+From: Daniel Veillard <veillard@redhat.com>
+Date: Tue, 14 Apr 2015 17:41:48 +0800
+Subject: [PATCH] CVE-2015-1819 Enforce the reader to run in constant memory
+
+One of the operation on the reader could resolve entities
+leading to the classic expansion issue. Make sure the
+buffer used for xmlreader operation is bounded.
+Introduce a new allocation type for the buffers for this effect.
+
+Upstream-Status: Backport
+
+Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
+Signed-off-by: Wenzong Fan <wenzong.fan@windriver.com>
+---
+ buf.c                 |   43 ++++++++++++++++++++++++++++++++++++++++++-
+ include/libxml/tree.h |    3 ++-
+ xmlreader.c           |   20 +++++++++++++++++++-
+ 3 files changed, 63 insertions(+), 3 deletions(-)
+
+diff --git a/buf.c b/buf.c
+index 6efc7b6..07922ff 100644
+--- a/buf.c
++++ b/buf.c
+@@ -27,6 +27,7 @@
+ #include <libxml/tree.h>
+ #include <libxml/globals.h>
+ #include <libxml/tree.h>
++#include <libxml/parserInternals.h> /* for XML_MAX_TEXT_LENGTH */
+ #include "buf.h"
+ 
+ #define WITH_BUFFER_COMPAT
+@@ -299,7 +300,8 @@ xmlBufSetAllocationScheme(xmlBufPtr buf,
+     if ((scheme == XML_BUFFER_ALLOC_DOUBLEIT) ||
+         (scheme == XML_BUFFER_ALLOC_EXACT) ||
+         (scheme == XML_BUFFER_ALLOC_HYBRID) ||
+-        (scheme == XML_BUFFER_ALLOC_IMMUTABLE)) {
++        (scheme == XML_BUFFER_ALLOC_IMMUTABLE) ||
++       (scheme == XML_BUFFER_ALLOC_BOUNDED)) {
+        buf->alloc = scheme;
+         if (buf->buffer)
+             buf->buffer->alloc = scheme;
+@@ -458,6 +460,18 @@ xmlBufGrowInternal(xmlBufPtr buf, size_t len) {
+     size = buf->use + len + 100;
+ #endif
+ 
++    if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
++        /*
++        * Used to provide parsing limits
++        */
++        if ((buf->use + len >= XML_MAX_TEXT_LENGTH) ||
++           (buf->size >= XML_MAX_TEXT_LENGTH)) {
++           xmlBufMemoryError(buf, "buffer error: text too long\n");
++           return(0);
++       }
++       if (size >= XML_MAX_TEXT_LENGTH)
++           size = XML_MAX_TEXT_LENGTH;
++    }
+     if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) {
+         size_t start_buf = buf->content - buf->contentIO;
+ 
+@@ -739,6 +753,15 @@ xmlBufResize(xmlBufPtr buf, size_t size)
+     CHECK_COMPAT(buf)
+ 
+     if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0);
++    if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
++        /*
++        * Used to provide parsing limits
++        */
++        if (size >= XML_MAX_TEXT_LENGTH) {
++           xmlBufMemoryError(buf, "buffer error: text too long\n");
++           return(0);
++       }
++    }
+ 
+     /* Don't resize if we don't have to */
+     if (size < buf->size)
+@@ -867,6 +890,15 @@ xmlBufAdd(xmlBufPtr buf, const xmlChar *str, int len) {
+ 
+     needSize = buf->use + len + 2;
+     if (needSize > buf->size){
++       if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
++           /*
++            * Used to provide parsing limits
++            */
++           if (needSize >= XML_MAX_TEXT_LENGTH) {
++               xmlBufMemoryError(buf, "buffer error: text too long\n");
++               return(-1);
++           }
++       }
+         if (!xmlBufResize(buf, needSize)){
+            xmlBufMemoryError(buf, "growing buffer");
+             return XML_ERR_NO_MEMORY;
+@@ -938,6 +970,15 @@ xmlBufAddHead(xmlBufPtr buf, const xmlChar *str, int len) {
+     }
+     needSize = buf->use + len + 2;
+     if (needSize > buf->size){
++       if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
++           /*
++            * Used to provide parsing limits
++            */
++           if (needSize >= XML_MAX_TEXT_LENGTH) {
++               xmlBufMemoryError(buf, "buffer error: text too long\n");
++               return(-1);
++           }
++       }
+         if (!xmlBufResize(buf, needSize)){
+            xmlBufMemoryError(buf, "growing buffer");
+             return XML_ERR_NO_MEMORY;
+diff --git a/include/libxml/tree.h b/include/libxml/tree.h
+index 2f90717..4a9b3bc 100644
+--- a/include/libxml/tree.h
++++ b/include/libxml/tree.h
+@@ -76,7 +76,8 @@ typedef enum {
+     XML_BUFFER_ALLOC_EXACT,    /* grow only to the minimal size */
+     XML_BUFFER_ALLOC_IMMUTABLE, /* immutable buffer */
+     XML_BUFFER_ALLOC_IO,       /* special allocation scheme used for I/O */
+-    XML_BUFFER_ALLOC_HYBRID    /* exact up to a threshold, and doubleit thereafter */
++    XML_BUFFER_ALLOC_HYBRID,   /* exact up to a threshold, and doubleit thereafter */
++    XML_BUFFER_ALLOC_BOUNDED   /* limit the upper size of the buffer */
+ } xmlBufferAllocationScheme;
+ 
+ /**
+diff --git a/xmlreader.c b/xmlreader.c
+index f19e123..471e7e2 100644
+--- a/xmlreader.c
++++ b/xmlreader.c
+@@ -2091,6 +2091,9 @@ xmlNewTextReader(xmlParserInputBufferPtr input, const char *URI) {
+                "xmlNewTextReader : malloc failed\n");
+        return(NULL);
+     }
++    /* no operation on a reader should require a huge buffer */
++    xmlBufSetAllocationScheme(ret->buffer,
++                             XML_BUFFER_ALLOC_BOUNDED);
+     ret->sax = (xmlSAXHandler *) xmlMalloc(sizeof(xmlSAXHandler));
+     if (ret->sax == NULL) {
+        xmlBufFree(ret->buffer);
+@@ -3616,6 +3619,7 @@ xmlTextReaderConstValue(xmlTextReaderPtr reader) {
+            return(((xmlNsPtr) node)->href);
+         case XML_ATTRIBUTE_NODE:{
+            xmlAttrPtr attr = (xmlAttrPtr) node;
++           const xmlChar *ret;
+ 
+            if ((attr->children != NULL) &&
+                (attr->children->type == XML_TEXT_NODE) &&
+@@ -3629,10 +3633,21 @@ xmlTextReaderConstValue(xmlTextReaderPtr reader) {
+                                         "xmlTextReaderSetup : malloc failed\n");
+                         return (NULL);
+                     }
++                   xmlBufSetAllocationScheme(reader->buffer,
++                                             XML_BUFFER_ALLOC_BOUNDED);
+                 } else
+                     xmlBufEmpty(reader->buffer);
+                xmlBufGetNodeContent(reader->buffer, node);
+-               return(xmlBufContent(reader->buffer));
++               ret = xmlBufContent(reader->buffer);
++               if (ret == NULL) {
++                   /* error on the buffer best to reallocate */
++                   xmlBufFree(reader->buffer);
++                   reader->buffer = xmlBufCreateSize(100);
++                   xmlBufSetAllocationScheme(reader->buffer,
++                                             XML_BUFFER_ALLOC_BOUNDED);
++                   ret = BAD_CAST "";
++               }
++               return(ret);
+            }
+            break;
+        }
+@@ -5131,6 +5146,9 @@ xmlTextReaderSetup(xmlTextReaderPtr reader,
+                         "xmlTextReaderSetup : malloc failed\n");
+         return (-1);
+     }
++    /* no operation on a reader should require a huge buffer */
++    xmlBufSetAllocationScheme(reader->buffer,
++                             XML_BUFFER_ALLOC_BOUNDED);
+     if (reader->sax == NULL)
+        reader->sax = (xmlSAXHandler *) xmlMalloc(sizeof(xmlSAXHandler));
+     if (reader->sax == NULL) {
+-- 
+1.7.9.5
+