libxml2: Add fix for CVE-2016-3709

Add below patch to fix CVE-2016-3709

CVE-2016-3709.patch
Link: https://github.com/GNOME/libxml2/commit/c1ba6f54d32b707ca6d91cb3257ce9de82876b6f

(From OE-Core rev: b9312041e4c8d565ad1e1102f8634bcc913adfa7)

Signed-off-by: Pawan Badganchi<pawan.badganchi@kpit.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 90 insertions, 0 deletions

diff --git a/meta/recipes-core/libxml/libxml2/CVE-2016-3709.patch b/meta/recipes-core/libxml/libxml2/CVE-2016-3709.patch
new file mode 100644
index 0000000000..5301d05323
--- /dev/null
+++ b/meta/recipes-core/libxml/libxml2/CVE-2016-3709.patch
@@ -0,0 +1,89 @@
+From c1ba6f54d32b707ca6d91cb3257ce9de82876b6f Mon Sep 17 00:00:00 2001
+From: Nick Wellnhofer <wellnhofer@aevum.de>
+Date: Sat, 15 Aug 2020 18:32:29 +0200
+Subject: [PATCH] Revert "Do not URI escape in server side includes"
+
+This reverts commit 960f0e275616cadc29671a218d7fb9b69eb35588.
+
+This commit introduced
+
+- an infinite loop, found by OSS-Fuzz, which could be easily fixed.
+- an algorithm with quadratic runtime
+- a security issue, see
+  https://bugzilla.gnome.org/show_bug.cgi?id=769760
+
+A better approach is to add an option not to escape URLs at all
+which libxml2 should have possibly done in the first place.
+
+CVE: CVE-2016-3709
+Upstream-Status: Backport [https://github.com/GNOME/libxml2/commit/c1ba6f54d32b707ca6d91cb3257ce9de82876b6f]
+Signed-off-by: Pawan Badganchi <Pawan.Badganchi@kpit.com>
+---
+ HTMLtree.c | 49 +++++++++++--------------------------------------
+ 1 file changed, 11 insertions(+), 38 deletions(-)
+
+diff --git a/HTMLtree.c b/HTMLtree.c
+index 8d236bb35..cdb7f86a6 100644
+--- a/HTMLtree.c
++++ b/HTMLtree.c
+@@ -706,49 +706,22 @@ htmlAttrDumpOutput(xmlOutputBufferPtr buf, xmlDocPtr doc, xmlAttrPtr cur,
+                 (!xmlStrcasecmp(cur->name, BAD_CAST "src")) ||
+                 ((!xmlStrcasecmp(cur->name, BAD_CAST "name")) &&
+                  (!xmlStrcasecmp(cur->parent->name, BAD_CAST "a"))))) {
++               xmlChar *escaped;
+                xmlChar *tmp = value;
+-               /* xmlURIEscapeStr() escapes '"' so it can be safely used. */
+-               xmlBufCCat(buf->buffer, "\"");
+
+                while (IS_BLANK_CH(*tmp)) tmp++;
+
+-               /* URI Escape everything, except server side includes. */
+-               for ( ; ; ) {
+-                   xmlChar *escaped;
+-                   xmlChar endChar;
+-                   xmlChar *end = NULL;
+-                   xmlChar *start = (xmlChar *)xmlStrstr(tmp, BAD_CAST "<!--");
+-                   if (start != NULL) {
+-                       end = (xmlChar *)xmlStrstr(tmp, BAD_CAST "-->");
+-                       if (end != NULL) {
+-                           *start = '\0';
+-                       }
+-                   }
+-
+-                   /* Escape the whole string, or until start (set to '\0'). */
+-                   escaped = xmlURIEscapeStr(tmp, BAD_CAST"@/:=?;#%&,+");
+-                   if (escaped != NULL) {
+-                       xmlBufCat(buf->buffer, escaped);
+-                       xmlFree(escaped);
+-                   } else {
+-                       xmlBufCat(buf->buffer, tmp);
+-                   }
+-
+-                   if (end == NULL) { /* Everything has been written. */
+-                       break;
+-                   }
+-
+-                   /* Do not escape anything within server side includes. */
+-                   *start = '<'; /* Restore the first character of "<!--". */
+-                   end += 3; /* strlen("-->") */
+-                   endChar = *end;
+-                   *end = '\0';
+-                   xmlBufCat(buf->buffer, start);
+-                   *end = endChar;
+-                   tmp = end;
++               /*
++                * the < and > have already been escaped at the entity level
++                * And doing so here breaks server side includes
++                */
++               escaped = xmlURIEscapeStr(tmp, BAD_CAST"@/:=?;#%&,+<>");
++               if (escaped != NULL) {
++                   xmlBufWriteQuotedString(buf->buffer, escaped);
++                   xmlFree(escaped);
++               } else {
++                   xmlBufWriteQuotedString(buf->buffer, value);
+                }
+-
+-               xmlBufCCat(buf->buffer, "\"");
+            } else {
+                xmlBufWriteQuotedString(buf->buffer, value);
+            }
diff --git a/meta/recipes-core/libxml/libxml2_2.9.10.bb b/meta/recipes-core/libxml/libxml2_2.9.10.bb
index d1c1f0884f..dc62991739 100644
--- a/meta/recipes-core/libxml/libxml2_2.9.10.bb
+++ b/meta/recipes-core/libxml/libxml2_2.9.10.bb
@@ -33,6 +33,7 @@ SRC_URI += "http://www.w3.org/XML/Test/xmlts20080827.tar.gz;subdir=${BP};name=te
            file://CVE-2022-29824-dependent.patch \
            file://CVE-2022-29824.patch \
            file://0001-Port-gentest.py-to-Python-3.patch \
+           file://CVE-2016-3709.patch \
            "
 
 SRC_URI[archive.sha256sum] = "593b7b751dd18c2d6abcd0c4bcb29efc203d0b4373a6df98e3a455ea74ae2813"