Patchwork [1/2,v2] libxml2 CVE-2012-2807

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Submitter jackie huang
Date June 21, 2013, 2:28 a.m.
Message ID <178fedbf79c6a303d0db3ef7af6b1b81b6b3342a.1371781463.git.jackie.huang@windriver.com>
Download mbox | patch
Permalink /patch/52193/
State New
Headers show

Comments

jackie huang - June 21, 2013, 2:28 a.m.
From: Jackie Huang <jackie.huang@windriver.com>

Multiple integer overflows in libxml2, as used in Google Chrome
before 20.0.1132.43, on 64-bit Linux platforms allow remote attackers to
cause a denial of service or possibly have unspecified other impact via unknown vectors.
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2012-2807

Signed-off-by: Li Wang <li.wang@windriver.com>
Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
---
 .../libxml/libxml2/libxml2-fix-CVE-2012-2807.patch |   80 ++++++++++++++++++++
 meta/recipes-core/libxml/libxml2_2.9.1.bb          |    1 +
 2 files changed, 81 insertions(+), 0 deletions(-)
 create mode 100644 meta/recipes-core/libxml/libxml2/libxml2-fix-CVE-2012-2807.patch

--
1.7.4.1
Ross Burton - June 21, 2013, 10:06 a.m.
On 21 June 2013 03:28,  <jackie.huang@windriver.com> wrote:
> +Upstream-Status: Backport

That's not strictly true.  Chromium has applied it to their in-tree
fork of libxml2, but it doesn't appear to be applied to libxml2 which
is what you're patching here.

Ross
Ross Burton - June 21, 2013, 12:24 p.m.
On 21 June 2013 11:06, Burton, Ross <ross.burton@intel.com> wrote:
> On 21 June 2013 03:28,  <jackie.huang@windriver.com> wrote:
>> +Upstream-Status: Backport

I'm now going as far as NACKing this.  The fact that a 2012 CVE
against a package that is under active development hasn't obviously
been merged raised a flag, so I spoke with upstream (crazy, I know!).

Basically libxml 2.9.0 introduced a new buffer system, and the patch
is Chromium is actually a simplified version of that code.  Thus, if
we have libxml 2.9.0 onwards we don't need this patch.

Ross

Patch

diff --git a/meta/recipes-core/libxml/libxml2/libxml2-fix-CVE-2012-2807.patch b/meta/recipes-core/libxml/libxml2/libxml2-fix-CVE-2012-2807.patch
new file mode 100644
index 0000000..7fb53c3
--- /dev/null
+++ b/meta/recipes-core/libxml/libxml2/libxml2-fix-CVE-2012-2807.patch
@@ -0,0 +1,80 @@ 
+Attempt to address libxml crash.
+
+Upstream-Status: Backport
+
+BUG=129930
+Review URL: https://chromiumcodereview.appspot.com/10458051
+
+https://src.chromium.org/viewvc/chrome?view=rev&revision=142822
+
+2012-2807
+Multiple integer overflows in libxml2, as used in Google Chrome
+before 20.0.1132.43, on 64-bit Linux platforms allow remote attackers to cause \
+a denial of service or possibly have unspecified other impact via unknown vectors.
+http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2012-2807
+
+Signed-off-by: Li Wang <li.wang@windriver.com>
+---
+ globals.c |   25 ++++++++++++++++++++++---
+ 1 files changed, 22 insertions(+), 3 deletions(-)
+
+diff --git a/globals.c b/globals.c
+index 69002f0..b369346 100644
+--- a/globals.c
++++ b/globals.c
+@@ -86,6 +86,25 @@ xmlMallocFunc xmlMallocAtomic = (xmlMallocFunc) xmlMemMalloc;
+ xmlReallocFunc xmlRealloc = (xmlReallocFunc) xmlMemRealloc;
+ xmlStrdupFunc xmlMemStrdup = (xmlStrdupFunc) xmlMemoryStrdup;
+ #else
++
++#define MAX_LIBXML_MALLOC (1024*1024*512)
++
++static void* size_checked_malloc(size_t size) {
++  if (size > MAX_LIBXML_MALLOC) {
++    *(volatile char*)0 = '\0';
++    return NULL;
++  }
++  return malloc(size);
++}
++
++static void* size_checked_realloc(void* ptr, size_t size) {
++  if (size > MAX_LIBXML_MALLOC) {
++    *(volatile char*)0 = '\0';
++    return NULL;
++  }
++  return realloc(ptr, size);
++}
++
+ /**
+  * xmlFree:
+  * @mem: an already allocated block of memory
+@@ -101,7 +120,7 @@ xmlFreeFunc xmlFree = (xmlFreeFunc) free;
+  *
+  * Returns a pointer to the newly allocated block or NULL in case of error
+  */
+-xmlMallocFunc xmlMalloc = (xmlMallocFunc) malloc;
++xmlMallocFunc xmlMalloc = (xmlMallocFunc) size_checked_malloc;
+ /**
+  * xmlMallocAtomic:
+  * @size:  the size requested in bytes
+@@ -112,7 +131,7 @@ xmlMallocFunc xmlMalloc = (xmlMallocFunc) malloc;
+  *
+  * Returns a pointer to the newly allocated block or NULL in case of error
+  */
+-xmlMallocFunc xmlMallocAtomic = (xmlMallocFunc) malloc;
++xmlMallocFunc xmlMallocAtomic = (xmlMallocFunc) size_checked_malloc;
+ /**
+  * xmlRealloc:
+  * @mem: an already allocated block of memory
+@@ -122,7 +141,7 @@ xmlMallocFunc xmlMallocAtomic = (xmlMallocFunc) malloc;
+  *
+  * Returns a pointer to the newly reallocated block or NULL in case of error
+  */
+-xmlReallocFunc xmlRealloc = (xmlReallocFunc) realloc;
++xmlReallocFunc xmlRealloc = (xmlReallocFunc) size_checked_realloc;
+ /**
+  * xmlMemStrdup:
+  * @str: a zero terminated string
+--
+1.7.0.5
+
diff --git a/meta/recipes-core/libxml/libxml2_2.9.1.bb b/meta/recipes-core/libxml/libxml2_2.9.1.bb
index a1093ed..11d8486 100644
--- a/meta/recipes-core/libxml/libxml2_2.9.1.bb
+++ b/meta/recipes-core/libxml/libxml2_2.9.1.bb
@@ -1,6 +1,7 @@ 
 require libxml2.inc

 SRC_URI += "file://libxml2-CVE-2012-2871.patch \
+	    file://libxml2-fix-CVE-2012-2807.patch \
 	   "

 SRC_URI[md5sum] = "9c0cfef285d5c4a5c80d00904ddab380"