Re: [xml] Crash while SAX parsing HTML

[Giovanni Donelli <giovanni donelli gmail com>]

Hi Daniel,

    thanks for the response. I did some additional debugging and I verified that the crash doesn't occur on the main thread, but is 100% reproducible on secondary thread. This explains why you cannot reproduce it with xmllint.

Here's the plain c code:

---- XMLParserBug.c ----

#include <libXML/HTMLparser.h>

#include <libXML/parser.h>

#include <string.h>

#include <fcntl.h>

#include <unistd.h>

#include <pthread.h>

#include <stdio.h>

xmlChar buffer[1024 * 128];

void* _thread(void *threadid)

{

printf("thread started\n");

fflush(stdout);

xmlSAXHandler _SAXParserFunctionHandlers;

memset( &_SAXParserFunctionHandlers, 0, sizeof(xmlSAXHandler) );

htmlDocPtr saxDoc = htmlSAXParseDoc(buffer, 

"utf-8", 

(htmlSAXHandlerPtr)&_SAXParserFunctionHandlers, 

NULL);

if (saxDoc)

xmlFreeDoc(saxDoc);

return NULL;

}

int main (int argc, const char * argv[]) 

{

memset( &buffer, 0, sizeof(buffer) );

int fd = open(argv[1], O_RDONLY);

if ( read(fd, &buffer, sizeof(buffer)) <= 0 ) { 

printf("Failed to read file\n");

return 1;

}

pthread_t thread;

if (pthread_create(&thread, NULL, _thread, NULL)) {

printf("pthread_create() failed\n");

return 1;

}

sleep(15);

return 0;

}

---- ---- ---- ---- ---- ---- ---- 

Steps to reproduce (on Mac OS X):

1. gcc XMLParserBug.c  -I/usr/include/libxml2 -I/usr/include/libxml2/libxml /usr/lib/libxml2.dylib -o parserbug

2. curl http://www.dlc.fi/~hurmari/index96.html > bugpage.html

3. ./parserbug bugpage.html 

thread started

Bus error

Any idea what could possibly go wrong here? Should I file a bug?

Thanks!

Giovanni

 I can't debug your code, but

 xmllint --sax --html http://www.dlc.fi/~hurmari/index96.html
seems to have no problem with the document, so I guess the problem
is on your side.

Daniel

--
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel veillard com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/