#48518 [Csd->Opn]: curl crashes when writing into invalid file handle
ID: 48518
Updated by: pajoye@php.net
Reported By: tony2001@php.net
-Status: Closed
+Status: Open
Bug Type: Reproducible crash
Operating System: Linux
PHP Version: 5.3CVS-2009-06-10 (CVS)
Assigned To: iliaa
New Comment:
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Previous Comments:
------------------------------------------------------------------------
[2009-06-26 17:33:33] rasmus@php.net
It looks like the fix for this broke this case:
<?php
$url = 'http://slowgeek.com/test.xml';
$cfile = '/var/tmp/test_'.$prefix.md5($url).'.xml';
$ch = curl_init();
curl_setopt($ch, CURLOPT_FILE, $fp = fopen($cfile,'w'));
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($ch, CURLOPT_TIMEOUT, 60);
curl_setopt($ch, CURLOPT_URL, $url);
$status = curl_exec($ch);
if(!$status) echo curl_error($ch);
fclose($fp);
curl_close($ch);
$data = file_get_contents($cfile);
var_dump($data); // 0 bytes here
fflush($fp); // fflush after the fclose??
$data = file_get_contents($cfile);
var_dump($data); // full contents here
------------------------------------------------------------------------
[2009-06-15 12:39:04] iliaa@php.net
This bug has been fixed in CVS.
Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
Thank you for the report, and for helping us make PHP better.
------------------------------------------------------------------------
[2009-06-10 13:41:23] tony2001@php.net
Found another piece of strange code:
PHP_FUNCTION(curl_exec)
....
ch->uses++;
if (ch->handlers->write->method == PHP_CURL_RETURN &&
ch->handlers->write->buf.len > 0) {
--ch->uses;
smart_str_0(&ch->handlers->write->buf);
RETURN_STRINGL(ch->handlers->write->buf.c,
ch->handlers->write->buf.len, 1);
}
--ch->uses;
...
What's the point in uses++ and immediate uses-- ?
------------------------------------------------------------------------
[2009-06-10 12:51:21] tony2001@php.net
Description:
------------
curl_setopt() doesn't increase reference count of file pointers passed
along with CURLOPT_FILE and CURLOPT_WRITEHEADER options, which leads to
invalid read/writes and as a result - random crashes because FILE*
pointer is destroyed before write().
Simple patch fixes this problem, but there is another one to consider:
should the refcount be decreased when closing the cURL handle?
Patch proposed: http://dev.daylessday.org/diff/curl_write_handle.diff
Reproduce code:
---------------
<?php
$tmp_dir = "/tmp/2";
$urls = array(
'http://ru.php.net/manual/en/function.curl-errno.php',
'http://ru.php.net/manual/en/function.curl-multi-close.php',
'http://ru.php.net/manual/en/function.curl-multi-getcontent.php',
'http://ru.php.net/manual/en/function.curl-multi-remove-handle.php',
);
$mh = curl_multi_init();
foreach ($urls as $url) {
$ch = curl_init();
$tmp_url = parse_url($url);
$tmp_file = $tmp_dir."/".basename($tmp_url['path']);
$fp = fopen($tmp_file, "w");
curl_setopt($ch, CURLOPT_RETURNTRANSFER,0);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_multi_add_handle($mh, $ch);
}
$running = 0;
do {
curl_multi_exec($mh, $running);
} while ($running > 0);
?>
Actual result:
--------------
==29222== Invalid read of size 2
==29222== at 0x60411F9: fwrite (in /lib64/libc-2.8.so)
==29222== by 0x45078F: curl_write (interface.c:882)
==29222== by 0x5738691: (within /usr/lib64/libcurl.so.4.0.1)
==29222== by 0x5750CC2: (within /usr/lib64/libcurl.so.4.0.1)
==29222== by 0x574D8F3: (within /usr/lib64/libcurl.so.4.0.1)
==29222== by 0x5752F7B: (within /usr/lib64/libcurl.so.4.0.1)
==29222== by 0x575380A: curl_multi_perform (in
/usr/lib64/libcurl.so.4.0.1)
==29222== by 0x45736A: zif_curl_multi_exec (multi.c:216)
==29222== by 0x6340F6: zend_do_fcall_common_helper_SPEC
(zend_vm_execute.h:313)
==29222== by 0x639955: ZEND_DO_FCALL_SPEC_CONST_HANDLER
(zend_vm_execute.h:1601)
==29222== by 0x633386: execute (zend_vm_execute.h:104)
==29222== by 0x6045FA: zend_execute_scripts (zend.c:1188)
==29222== by 0x58FFDE: php_execute_script (main.c:2171)
==29222== by 0x6E904A: main (php_cli.c:1188)
==29222== Invalid write of size 8
==29222== at 0x6041245: fwrite (in /lib64/libc-2.8.so)
==29222== by 0x45078F: curl_write (interface.c:882)
==29222== by 0x5738691: (within /usr/lib64/libcurl.so.4.0.1)
==29222== by 0x5750CC2: (within /usr/lib64/libcurl.so.4.0.1)
==29222== by 0x574D8F3: (within /usr/lib64/libcurl.so.4.0.1)
==29222== by 0x5752F7B: (within /usr/lib64/libcurl.so.4.0.1)
==29222== by 0x575380A: curl_multi_perform (in
/usr/lib64/libcurl.so.4.0.1)
==29222== by 0x45736A: zif_curl_multi_exec (multi.c:216)
==29222== by 0x6340F6: zend_do_fcall_common_helper_SPEC
(zend_vm_execute.h:313)
==29222== by 0x639955: ZEND_DO_FCALL_SPEC_CONST_HANDLER
(zend_vm_execute.h:1601)
==29222== by 0x633386: execute (zend_vm_execute.h:104)
==29222== by 0x6045FA: zend_execute_scripts (zend.c:1188)
==29222== by 0x58FFDE: php_execute_script (main.c:2171)
==29222== by 0x6E904A: main (php_cli.c:1188)
------------------------------------------------------------------------
--
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