CVE-2014-9652

Community BUG:

https://bugs.php.net/bug.php?id=68735

Community CODE:

https://bugs.php.net/patch-display.php?bug=68735&patch=bug68735.patch&revision=1420309079

Below is the community patch.

diff --git a/ext/fileinfo/libmagic/softmagic.c b/ext/fileinfo/libmagic/softmagic.c

index 7e0c856..e7b7855 100644

--- a/ext/fileinfo/libmagic/softmagic.c

+++ b/ext/fileinfo/libmagic/softmagic.c

@@ -884,14 +884,17 @@ mconvert(struct magic_set *ms, struct magic *m, int flip)

 		size_t sz = file_pstring_length_size(m);

 		char *ptr1 = p->s, *ptr2 = ptr1 + sz;

 		size_t len = file_pstring_get_length(m, ptr1);

-		if (len >= sizeof(p->s)) {

+		sz = sizeof(p->s) - sz; /* maximum length of string */

+		if (len >= sz) {

 			/*

 			 * The size of the pascal string length (sz)

 			 * is 1, 2, or 4. We need at least 1 byte for NUL

 			 * termination, but we've already truncated the

 			 * string by p->s, so we need to deduct sz.

+			 * Because we can use one of the bytes of the length

+			 * after we shifted as NUL termination.

 			 */ 

-			len = sizeof(p->s) - sz;

+			len = sz;

 		}

 		while (len--)

 			*ptr1++ = *ptr2++;

--- /dev/null	Sat Jan  3 19:01:50 2015

+++ a/ext/fileinfo/tests/bug68735.phpt	Sat Jan  3 18:57:32 2015

@@ -0,0 +1,16 @@

+--TEST--

+Bug #68735 fileinfo out-of-bounds memory access

+--SKIPIF--

+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>

+--FILE--

+<?php

+	$test_file = dirname(__FILE__) . DIRECTORY_SEPARATOR . "bug68735.jpg";

+	$f = new finfo;

+

+	var_dump($f->file($test_file));

+

+?>

+===DONE===

+--EXPECTF--

+string(%d) "JPEG image data, JFIF standard 1.01, comment: "%S""

+===DONE===