com php-src: fix possible out of bounds buffer access: Zend/zend_virtual_cwd.c

Commit:    feeb35e438db36f08bb82d493b11d4211201f23c
Author:    Anatol Belski <[email protected]>         Mon, 3 Apr 2017 15:20:32 +0200
Parents:   670041b60ec25e822564d337bae96e82e8d9ac89
Branches:  PHP-7.0 PHP-7.1 master

Link:       http://git.php.net/?p=php-src.git;a=commitdiff;h=feeb35e438db36f08bb82d493b11d4211201f23c

Log:
fix possible out of bounds buffer access

Changed paths:
  M  Zend/zend_virtual_cwd.c


Diff:
diff --git a/Zend/zend_virtual_cwd.c b/Zend/zend_virtual_cwd.c
index ca19802..8009f2f 100644
--- a/Zend/zend_virtual_cwd.c
+++ b/Zend/zend_virtual_cwd.c
@@ -380,7 +380,7 @@ CWD_API int php_sys_stat_ex(const char *path, zend_stat_t *buf, int lstat) /* {{
 	if ((data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == 0) {
 		size_t len = strlen(path);
 
-		if (path[len-4] == '.') {
+		if (len >= 4 && path[len-4] == '.') {
 			if (_memicmp(path+len-3, "exe", 3) == 0 ||
 				_memicmp(path+len-3, "com", 3) == 0 ||
 				_memicmp(path+len-3, "bat", 3) == 0 ||