ID: 29349
Comment by: adconrad at debian dot org
Reported By: k at ailis dot de
Status: Bogus
Bug Type: GD related
Operating System: Linux
PHP Version: 4CVS-2004-07-23 (stable)
New Comment:
I'm not entirely sure which planet you're from, but a double-free bug
from incorrect usage of a library is not a "bogus" bug.
Distributions link to external libraries because symbol clashes in
shared application space is BAD (and your internal library doesn't use
versioned symbols) and because security updates to a dozen statically
compiled packages is much more of a pain in the ass than security
updates to an individual library.
If you don't want distributions to package your stuff, get a consensus
from your contributors and slap a more restructive license on it. If
you do want it being used widely, get rid of your NIH attitude and
realise that YOU bundled libgd, they didn't "steal" it from you and
"break" it. It's your bundled version that you broke to work around a
bug in PHP, rather than fixing the PHP bug. That's not sane.
Previous Comments:
------------------------------------------------------------------------
[2004-07-25 21:42:11] k at ailis dot de
Then why are you not modifying your configure system so it
checks to have at least GD 2.0.21 if the external GD lib
is used? If you are argumenting that everyone should use
the bundled GD lib anyway then you don't need to bother
with those poor users which are not having at least GD
2.0.21.
But if you don't want to "exclude" users of older GD
libraries and you think it's ok that these users are not
able to use some PHP functions without segfaults then you
can do some conditional compiling. In that way you can
help users by saying "Update to GD 2.0.21 or better and
recompile PHP OR use the bundled GD" instead of insisting
only on the usage of the bundled one.
But slowly the impression comes to me that you don't want
users to use the external GD. You are already no longer
giving support for the usage of the external one (At least
nothing else then the silly "use the bundled GD library"
response which does not respect the fact that the user may
have reasons to use the external library). So maybe you
should be consequential and remove compilation support for
the external GD completely. Then you have no longer to
deal with bug reports like this...
------------------------------------------------------------------------
[2004-07-25 21:10:18] [EMAIL PROTECTED]
The patch relies on a function only available in later
versions of GD, which not everyone has. The bundled GD has
no problem what so over and should be used.
------------------------------------------------------------------------
[2004-07-25 20:54:32] k at ailis dot de
Narf... This is NOT a bug in the GD library. The function
you are using is freeing memory because this function is
MEANT to do exactly this because this function normally
deals with data which was allocated by GD itself. But you
are passing data to this function which was allocated by
YOU. Boutell has already dealt with this problem and has
created new functions which exactly suit your needs: The
gdImageCreateFrom*Ptr functions and also the
gdNewDynamicCtxEx function. RTFM:
* The new gdNewDynamicCtxEx function was added to
support the easy
implementation of the above functions and to
correct a design
problem which made life unpleasant for those
passing in memory not
originally allocated by gd to the gdNewDynamicCtx
function by
providing a way to specify that gd should never
free or reallocate
a particular block of memory. The gdNewDynamicCtx
function and its
relatives, although still exported for ABI
compatibility, are now
deprecated except for internal use, in favor of
[45]gdImageCreateFromPngPtr and its relatives.
So please stop putting your head in the sand and apply
Adam Conrad's patch or move to the new
gdImageCreateFrom*Ptr functions.
------------------------------------------------------------------------
[2004-07-25 19:28:39] [EMAIL PROTECTED]
Sorry, but your problem does not imply a bug in PHP itself. For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions.
Thank you for your interest in PHP.
This is a bug in the GD library, we recommend to always use
the bundled GD library, which as you've indicated does not
have this problem.
------------------------------------------------------------------------
[2004-07-25 15:21:35] adconrad at debian dot org
As of the next upload to the Debian archive, we will be using the
following patch, which seems to clear up every php4-gd segfault bug
we've had reported:
--- php4-4.3.8/ext/gd/gd.c.orig 2004-07-24 06:00:25.000000000 -0600
+++ php4-4.3.8/ext/gd/gd.c 2004-07-24 06:10:38.000000000 -0600
@@ -1242,7 +1242,7 @@
#ifdef HAVE_GD_WBMP
else {
gdIOCtx *io_ctx;
- io_ctx = gdNewDynamicCtx (8, data);
+ io_ctx = gdNewDynamicCtxEx (8, data, 0);
if (io_ctx) {
if (getmbi((int(*)(void*))gdGetC, io_ctx) == 0
&& skipheader((int(*)(void*))gdGetC, io_ctx) == 0 ) {
#if HAVE_LIBGD204
@@ -1274,7 +1274,7 @@
gdImagePtr im;
gdIOCtx *io_ctx;
- io_ctx = gdNewDynamicCtx (Z_STRLEN_PP(data),
Z_STRVAL_PP(data));
+ io_ctx = gdNewDynamicCtxEx (Z_STRLEN_PP(data),
Z_STRVAL_PP(data), 0);
if (!io_ctx) {
return NULL;
@@ -1428,7 +1428,7 @@
goto out_err;
}
- io_ctx = gdNewDynamicCtx(buff_size, buff);
+ io_ctx = gdNewDynamicCtxEx(buff_size, buff, 0);
if(!io_ctx) {
php_error_docref(NULL TSRMLS_CC,
E_WARNING,"Cannot allocate GD IO context");
goto out_err;
------------------------------------------------------------------------
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the rest of the comments, please view the bug report online at
http://bugs.php.net/29349
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