1 Taken as it's from:

     2 

     3 http://git.gnome.org/browse/libxslt/commit/?id=ecb6bcb8d1b7e44842edde3929f412d46b40c89f

     4 

     5 For https://bugzilla.redhat.com/show_bug.cgi?id=684386

     6 CVE-2011-1202

     7 

     8 From ecb6bcb8d1b7e44842edde3929f412d46b40c89f Mon Sep 17 00:00:00 2001

     9 From: Daniel Veillard <[email protected]>

    10 Date: Tue, 22 Feb 2011 02:14:23 +0000

    11 Subject: Fix generate-id() to not expose object addresses

    12 

    13 As pointed out by Chris Evans <[email protected]> it's better

    14 security wise to not expose object addresses directly, use a diff

    15 w.r.t. the document root own address to avoid this

    16 * libxslt/functions.c: fix IDs generation code

    17 ---

    18 diff --git a/libxslt/functions.c b/libxslt/functions.c

    19 index 4720c7a..de962f4 100644

    20 --- a/libxslt/functions.c

    21 +++ b/libxslt/functions.c

    22 @@ -654,8 +654,9 @@ xsltFormatNumberFunction(xmlXPathParserContextPtr ctxt, int nargs)

    23  void

    24  xsltGenerateIdFunction(xmlXPathParserContextPtr ctxt, int nargs){

    25      xmlNodePtr cur = NULL;

    26 -    unsigned long val;

    27 -    xmlChar str[20];

    28 +    long val;

    29 +    xmlChar str[30];

    30 +    xmlDocPtr doc;

    31  

    32      if (nargs == 0) {

    33  	cur = ctxt->context->node;

    34 @@ -694,9 +695,24 @@ xsltGenerateIdFunction(xmlXPathParserContextPtr ctxt, int nargs){

    35       * Okay this is ugly but should work, use the NodePtr address

    36       * to forge the ID

    37       */

    38 -    val = (unsigned long)((char *)cur - (char *)0);

    39 -    val /= sizeof(xmlNode);

    40 -    sprintf((char *)str, "id%ld", val);

    41 +    if (cur->type != XML_NAMESPACE_DECL)

    42 +        doc = cur->doc;

    43 +    else {

    44 +        xmlNsPtr ns = (xmlNsPtr) cur;

    45 +

    46 +        if (ns->context != NULL)

    47 +            doc = ns->context;

    48 +        else

    49 +            doc = ctxt->context->doc;

    50 +

    51 +    }

    52 +

    53 +    val = (long)((char *)cur - (char *)doc);

    54 +    if (val >= 0) {

    55 +      sprintf((char *)str, "idp%ld", val);

    56 +    } else {

    57 +      sprintf((char *)str, "idm%ld", -val);

    58 +    }

    59      valuePush(ctxt, xmlXPathNewString(str));

    60  }

    61  

    62 --

    63 cgit v0.9.0.2