shaba/libxml2
1
0
Fork 0
mirror of https://gitlab.gnome.org/GNOME/libxml2.git synced 2024-10-27 04:55:04 +03:00
Code Releases Activity

Never expand parameter entities in text declaration

Browse Source 
When parsing the text declaration of external DTDs or entities, make
sure that parameter entities are not expanded. This also fixes a memory
leak in certain error cases.

The change to xmlSkipBlankChars assumes that the parser state is
maintained correctly when parsing external DTDs or parameter entities,
and might expose bugs in the code that were hidden previously.

Found by OSS-Fuzz.
This commit is contained in:
Nick Wellnhofer 2020-06-10 13:41:13 +02:00
parent 487871b0e3
commit a28f7d8789
1 changed files with 9 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
parser.c
View File

@ -2156,7 +2156,7 @@ xmlSkipBlankChars(xmlParserCtxtPtr ctxt) {
* It's Okay to use CUR/NEXT here since all the blanks are on
* the ASCII range.
*/
if ((ctxt->inputNr == 1) && (ctxt->instate != XML_PARSER_DTD)) {
if (ctxt->instate != XML_PARSER_DTD) {
const xmlChar *cur;
/*
* if we are in the document content, go really fast
@ -6852,6 +6852,7 @@ void
xmlParseTextDecl(xmlParserCtxtPtr ctxt) {
xmlChar *version;
const xmlChar *encoding;
int oldstate;
/*
* We know that '<?xml' is here.
@ -6863,6 +6864,10 @@ xmlParseTextDecl(xmlParserCtxtPtr ctxt) {
return;
}
/* Avoid expansion of parameter entities when skipping blanks. */
oldstate = ctxt->instate;
ctxt->instate = XML_PARSER_START;
if (SKIP_BLANKS == 0) {
xmlFatalErrMsg(ctxt, XML_ERR_SPACE_REQUIRED,
"Space needed after '<?xml'\n");
@ -6890,6 +6895,7 @@ xmlParseTextDecl(xmlParserCtxtPtr ctxt) {
/*
* The XML REC instructs us to stop parsing right here
*/
ctxt->instate = oldstate;
return;
}
if ((encoding == NULL) && (ctxt->errNo == XML_ERR_OK)) {
@ -6909,6 +6915,8 @@ xmlParseTextDecl(xmlParserCtxtPtr ctxt) {
MOVETO_ENDTAG(CUR_PTR);
NEXT;
}
ctxt->instate = oldstate;
}
/**