From ed4feb5986fb8fe484c4423de22f1c3753b45f5c Mon Sep 17 00:00:00 2001
From: csteipp <csteipp@wikimedia.org>
Date: Thu, 19 Dec 2013 12:52:18 -0800
Subject: [PATCH] SECURITY: Return error on invalid XML for SVGs

Return an error from UploadBase::detectScriptInSvg when the svg has
XML that cannot be parsed. Usually the XML is invalid, or the parser has
run out of memory trying to parse the file.

This patch is rebased on top of bug 57550.

Bug: 58553
Change-Id: I32661a27d7417cc2c69b844c805b190d6486d17a
---
 includes/upload/UploadBase.php     | 15 +++++++++++----
 languages/messages/MessagesEn.php  |  1 +
 languages/messages/MessagesQqq.php |  1 +
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/includes/upload/UploadBase.php b/includes/upload/UploadBase.php
index d801229..a748cc9 100644
--- a/includes/upload/UploadBase.php
+++ b/includes/upload/UploadBase.php
@@ -476,9 +476,10 @@ abstract class UploadBase {
 				return array( 'uploadscripted' );
 			}
 			if ( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
-				if ( $this->detectScriptInSvg( $this->mTempPath ) ) {
+				$svgStatus = $this->detectScriptInSvg( $this->mTempPath );
+				if ( $svgStatus !== false ) {
 					wfProfileOut( __METHOD__ );
-					return array( 'uploadscripted' );
+					return $svgStatus;
 				}
 			}
 		}
@@ -1155,7 +1156,7 @@ abstract class UploadBase {
 
 	/**
 	 * @param $filename string
-	 * @return bool
+	 * @return mixed false of the file is verified (does not contain scripts), array otherwise.
 	 */
 	protected function detectScriptInSvg( $filename ) {
 		$check = new XmlTypeCheck(
@@ -1164,7 +1165,13 @@ abstract class UploadBase {
 			true,
 			array( 'processing_instruction_handler' => 'UploadBase::checkSvgPICallback' )
 		);
-		return $check->filterMatch;
+		if ( $check->wellFormed !== true ) {
+			// Invalid xml (bug 58553)
+			return array( 'uploadinvalidxml' );
+		} elseif ( $check->filterMatch ) {
+			return array( 'uploadscripted' );
+		}
+		return false;
 	}
 
 	/**
diff --git a/languages/messages/MessagesEn.php b/languages/messages/MessagesEn.php
index a4c2056..1128e81 100644
--- a/languages/messages/MessagesEn.php
+++ b/languages/messages/MessagesEn.php
@@ -2335,6 +2335,7 @@ You should check that file's deletion history before proceeding to re-upload it.
 'php-uploaddisabledtext'      => 'File uploads are disabled in PHP.
 Please check the file_uploads setting.',
 'uploadscripted'              => 'This file contains HTML or script code that may be erroneously interpreted by a web browser.',
+'uploadinvalidxml'            => 'The XML in the uploaded file could not be parsed.',
 'uploadvirus'                 => 'The file contains a virus!
 Details: $1',
 'uploadjava'                  => 'The file is a ZIP file that contains a Java .class file.
diff --git a/languages/messages/MessagesQqq.php b/languages/messages/MessagesQqq.php
index 807bedd..e4c8dc4 100644
--- a/languages/messages/MessagesQqq.php
+++ b/languages/messages/MessagesQqq.php
@@ -4050,6 +4050,7 @@ See also:
 * {{msg-mw|zip-wrong-format}}
 * {{msg-mw|uploadjava}}
 * {{msg-mw|uploadvirus}}',
+'uploadinvalidxml' => 'Error message displayed when the uploaded file contains XML that cannot be properly parsed and checked.',
 'uploadvirus' => 'Error message displayed when uploaded file contains a virus.
 
 Parameters:
-- 
1.8.4