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Introduce some default parser limits

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Those can be overrided by the XML_PARSE_HUGE option, they
are just default limits for Name lenght, dictionary size limits
and maximum amount of parser lookup.
* include/libxml/parserInternals.h: define the limits
* include/libxml/xmlerror.h: add a new error
* parser.c parserInternals.c: implements the new limits
This commit is contained in:
Daniel Veillard 2012-07-30 10:08:45 +08:00
parent 7c693dad23
commit 52d8ade7a7
4 changed files with 118 additions and 4 deletions
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35
include/libxml/parserInternals.h
View File

@ -1,5 +1,5 @@
/*
* Summary: internals routines exported by the parser.
* Summary: internals routines and limits exported by the parser.
* Description: this module exports a number of internal parsing routines
* they are not really all intended for applications but
* can prove useful doing low level processing.
@ -36,9 +36,42 @@ XMLPUBVAR unsigned int xmlParserMaxDepth;
* Maximum size allowed for a single text node when building a tree.
* This is not a limitation of the parser but a safety boundary feature,
* use XML_PARSE_HUGE option to override it.
* Introduced in 2.9.0
*/
#define XML_MAX_TEXT_LENGTH 10000000
/**
* XML_MAX_NAME_LENGTH:
*
* Maximum size allowed for a markup identitier
* This is not a limitation of the parser but a safety boundary feature,
* use XML_PARSE_HUGE option to override it.
* Note that with the use of parsing dictionaries overriding the limit
* may result in more runtime memory usage in face of "unfriendly' content
* Introduced in 2.9.0
*/
#define XML_MAX_NAME_LENGTH 50000
/**
* XML_MAX_DICTIONARY_LIMIT:
*
* Maximum size allowed by the parser for a dictionary by default
* This is not a limitation of the parser but a safety boundary feature,
* use XML_PARSE_HUGE option to override it.
* Introduced in 2.9.0
*/
#define XML_MAX_DICTIONARY_LIMIT 10000000
/**
* XML_MAX_LOOKUP_LIMIT:
*
* Maximum size allowed by the parser for ahead lookup
* This is an upper boundary enforced by the parser to avoid bad
* behaviour on "unfriendly' content
* Introduced in 2.9.0
*/
#define XML_MAX_LOOKUP_LIMIT 10000000
/**
* XML_MAX_NAMELEN:
*

1
include/libxml/xmlerror.h
View File

@ -207,6 +207,7 @@ typedef enum {
XML_WAR_ENTITY_REDEFINED, /* 107 */
XML_ERR_UNKNOWN_VERSION, /* 108 */
XML_ERR_VERSION_MISMATCH, /* 109 */
XML_ERR_NAME_TOO_LONG, /* 110 */
XML_NS_ERR_XML_NAMESPACE = 200,
XML_NS_ERR_UNDEFINED_NAMESPACE, /* 201 */
XML_NS_ERR_QNAME, /* 202 */

84
parser.c
View File

@ -464,6 +464,9 @@ xmlFatalErr(xmlParserCtxtPtr ctxt, xmlParserErrors error, const char *info)
case XML_ERR_VERSION_MISSING:
errmsg = "Malformed declaration expecting version\n";
break;
case XML_ERR_NAME_TOO_LONG:
errmsg = "Name too long use XML_PARSE_HUGE option\n";
break;
#if 0
case:
errmsg = "\n";
@ -2004,6 +2007,11 @@ static void xmlSHRINK (xmlParserCtxtPtr ctxt) {
xmlGROW (ctxt);
static void xmlGROW (xmlParserCtxtPtr ctxt) {
if ((((ctxt->input->end - ctxt->input->cur) > XML_MAX_LOOKUP_LIMIT) ||
((ctxt->input->cur - ctxt->input->base) > XML_MAX_LOOKUP_LIMIT)) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_INTERNAL_ERROR, "Huge input lookup");
}
xmlParserInputGrow(ctxt->input, INPUT_CHUNK);
if ((ctxt->input->cur != NULL) && (*ctxt->input->cur == 0) &&
(xmlParserInputGrow(ctxt->input, INPUT_CHUNK) <= 0))
@ -3262,6 +3270,11 @@ xmlParseNameComplex(xmlParserCtxtPtr ctxt) {
c = CUR_CHAR(l);
}
}
if ((len > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "Name");
return(NULL);
}
if ((*ctxt->input->cur == '\n') && (ctxt->input->cur[-1] == '\r'))
return(xmlDictLookup(ctxt->dict, ctxt->input->cur - (len + 1), len));
return(xmlDictLookup(ctxt->dict, ctxt->input->cur - len, len));
@ -3311,6 +3324,11 @@ xmlParseName(xmlParserCtxtPtr ctxt) {
in++;
if ((*in > 0) && (*in < 0x80)) {
count = in - ctxt->input->cur;
if ((count > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "Name");
return(NULL);
}
ret = xmlDictLookup(ctxt->dict, ctxt->input->cur, count);
ctxt->input->cur = in;
ctxt->nbChars += count;
@ -3347,6 +3365,11 @@ xmlParseNCNameComplex(xmlParserCtxtPtr ctxt) {
while ((c != ' ') && (c != '>') && (c != '/') && /* test bigname.xml */
(xmlIsNameChar(ctxt, c) && (c != ':'))) {
if (count++ > 100) {
if ((len > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName");
return(NULL);
}
count = 0;
GROW;
}
@ -3354,6 +3377,11 @@ xmlParseNCNameComplex(xmlParserCtxtPtr ctxt) {
NEXTL(l);
c = CUR_CHAR(l);
}
if ((len > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName");
return(NULL);
}
return(xmlDictLookup(ctxt->dict, ctxt->input->cur - len, len));
}
@ -3398,6 +3426,11 @@ xmlParseNCName(xmlParserCtxtPtr ctxt) {
in++;
if ((*in > 0) && (*in < 0x80)) {
count = in - ctxt->input->cur;
if ((count > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName");
return(NULL);
}
ret = xmlDictLookup(ctxt->dict, ctxt->input->cur, count);
ctxt->input->cur = in;
ctxt->nbChars += count;
@ -3508,6 +3541,13 @@ xmlParseStringName(xmlParserCtxtPtr ctxt, const xmlChar** str) {
while (xmlIsNameChar(ctxt, c)) {
if (len + 10 > max) {
xmlChar *tmp;
if ((len > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName");
xmlFree(buffer);
return(NULL);
}
max *= 2;
tmp = (xmlChar *) xmlRealloc(buffer,
max * sizeof(xmlChar));
@ -3527,6 +3567,11 @@ xmlParseStringName(xmlParserCtxtPtr ctxt, const xmlChar** str) {
return(buffer);
}
}
if ((len > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NCName");
return(NULL);
}
*str = cur;
return(xmlStrndup(buf, len));
}
@ -3588,6 +3633,12 @@ xmlParseNmtoken(xmlParserCtxtPtr ctxt) {
if (len + 10 > max) {
xmlChar *tmp;
if ((max > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NmToken");
xmlFree(buffer);
return(NULL);
}
max *= 2;
tmp = (xmlChar *) xmlRealloc(buffer,
max * sizeof(xmlChar));
@ -3608,6 +3659,11 @@ xmlParseNmtoken(xmlParserCtxtPtr ctxt) {
}
if (len == 0)
return(NULL);
if ((len > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "NmToken");
return(NULL);
}
return(xmlStrndup(buf, len));
}
@ -4067,6 +4123,13 @@ xmlParseSystemLiteral(xmlParserCtxtPtr ctxt) {
if (len + 5 >= size) {
xmlChar *tmp;
if ((size > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "SystemLiteral");
xmlFree(buf);
ctxt->instate = (xmlParserInputState) state;
return(NULL);
}
size *= 2;
tmp = (xmlChar *) xmlRealloc(buf, size * sizeof(xmlChar));
if (tmp == NULL) {
@ -4144,6 +4207,12 @@ xmlParsePubidLiteral(xmlParserCtxtPtr ctxt) {
if (len + 1 >= size) {
xmlChar *tmp;
if ((size > XML_MAX_NAME_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "Public ID");
xmlFree(buf);
return(NULL);
}
size *= 2;
tmp = (xmlChar *) xmlRealloc(buf, size * sizeof(xmlChar));
if (tmp == NULL) {
@ -8334,7 +8403,7 @@ xmlParseStartTag(xmlParserCtxtPtr ctxt) {
xmlFree(attvalue);
}
failed:
failed:
GROW
if ((RAW == '>') || (((RAW == '/') && (NXT(1) == '>'))))
@ -9519,14 +9588,21 @@ xmlParseCDSect(xmlParserCtxtPtr ctxt) {
if (len + 5 >= size) {
xmlChar *tmp;
size *= 2;
tmp = (xmlChar *) xmlRealloc(buf, size * sizeof(xmlChar));
if ((size > XML_MAX_TEXT_LENGTH) &&
((ctxt->options & XML_PARSE_HUGE) == 0)) {
xmlFatalErrMsgStr(ctxt, XML_ERR_CDATA_NOT_FINISHED,
"CData section too big found", NULL);
xmlFree (buf);
return;
}
tmp = (xmlChar *) xmlRealloc(buf, size * 2 * sizeof(xmlChar));
if (tmp == NULL) {
xmlFree(buf);
xmlErrMemory(ctxt, NULL);
return;
}
buf = tmp;
size *= 2;
}
COPY_BUF(rl,buf,len,r);
r = s;
@ -14751,6 +14827,8 @@ xmlCtxtUseOptionsInternal(xmlParserCtxtPtr ctxt, int options, const char *encodi
if (options & XML_PARSE_HUGE) {
ctxt->options |= XML_PARSE_HUGE;
options -= XML_PARSE_HUGE;
if (ctxt->dict != NULL)
xmlDictSetLimit(ctxt->dict, 0);
}
if (options & XML_PARSE_OLDSAX) {
ctxt->options |= XML_PARSE_OLDSAX;

2
parserInternals.c
View File

@ -1578,6 +1578,8 @@ xmlInitParserCtxt(xmlParserCtxtPtr ctxt)
xmlErrMemory(NULL, "cannot initialize parser context\n");
return(-1);
}
xmlDictSetLimit(ctxt->dict, XML_MAX_DICTIONARY_LIMIT);
if (ctxt->sax == NULL)
ctxt->sax = (xmlSAXHandler *) xmlMalloc(sizeof(xmlSAXHandler));
if (ctxt->sax == NULL) {