libyaml: add fix for CVE-2014-2525 Security Advisory

Heap-based buffer overflow in the yaml_parser_scan_uri_escapes function
in LibYAML before 0.1.6 allows context-dependent attackers to execute
arbitrary code via a long sequence of percent-encoded characters in a
URI in a YAML file.

http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-2525

Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
Signed-off-by: Kai Kang <kai.kang@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

2 files changed, 45 insertions, 1 deletions

diff --git a/meta-oe/recipes-support/libyaml/files/libyaml-CVE-2014-2525.patch b/meta-oe/recipes-support/libyaml/files/libyaml-CVE-2014-2525.patch
new file mode 100644
index 0000000000..2fdcba3eca
--- /dev/null
+++ b/meta-oe/recipes-support/libyaml/files/libyaml-CVE-2014-2525.patch
@@ -0,0 +1,42 @@
+Heap-based buffer overflow in the yaml_parser_scan_uri_escapes function
+in LibYAML before 0.1.6 allows context-dependent attackers to execute
+arbitrary code via a long sequence of percent-encoded characters in a
+URI in a YAML file.
+
+Upstream-Status: Backport
+
+Signed-off-by: Kai Kang <kai.kang@windriver.com>
+---
+diff --git a/src/scanner.c.old b/src/scanner.c
+index a2e8619..c6cde3b 100644
+--- a/src/scanner.c.old
++++ b/src/scanner.c
+@@ -2619,6 +2619,9 @@ yaml_parser_scan_tag_uri(yaml_parser_t *parser, int directive,
+         /* Check if it is a URI-escape sequence. */
+ 
+         if (CHECK(parser->buffer, '%')) {
++            if (!STRING_EXTEND(parser, string))
++                goto error;
++
+             if (!yaml_parser_scan_uri_escapes(parser,
+                         directive, start_mark, &string)) goto error;
+         }
+diff --git a/src/yaml_private.h.old b/src/yaml_private.h
+index ed5ea66..d72acb4 100644
+--- a/src/yaml_private.h.old
++++ b/src/yaml_private.h
+@@ -132,9 +132,12 @@ yaml_string_join(
+      (string).start = (string).pointer = (string).end = 0)
+ 
+ #define STRING_EXTEND(context,string)                                           \
+-    (((string).pointer+5 < (string).end)                                        \
++    ((((string).pointer+5 < (string).end)                                       \
+         || yaml_string_extend(&(string).start,                                  \
+-            &(string).pointer, &(string).end))
++            &(string).pointer, &(string).end)) ?                                \
++         1 :                                                                    \
++        ((context)->error = YAML_MEMORY_ERROR,                                  \
++         0))
+ 
+ #define CLEAR(context,string)                                                   \
+     ((string).pointer = (string).start,                                         \
diff --git a/meta-oe/recipes-support/libyaml/libyaml_0.1.5.bb b/meta-oe/recipes-support/libyaml/libyaml_0.1.5.bb
index c44eda4ee1..1279541966 100644
--- a/meta-oe/recipes-support/libyaml/libyaml_0.1.5.bb
+++ b/meta-oe/recipes-support/libyaml/libyaml_0.1.5.bb
@@ -7,7 +7,9 @@ SECTION = "libs/devel"
 LICENSE = "MIT"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=6015f088759b10e0bc2bf64898d4ae17"
 
-SRC_URI = "http://pyyaml.org/download/libyaml/yaml-${PV}.tar.gz"
+SRC_URI = "http://pyyaml.org/download/libyaml/yaml-${PV}.tar.gz \
+           file://libyaml-CVE-2014-2525.patch \
+          "
 
 SRC_URI[md5sum] = "24f6093c1e840ca5df2eb09291a1dbf1"
 SRC_URI[sha256sum] = "fa87ee8fb7b936ec04457bc044cd561155e1000a4d25029867752e543c2d3bef"