#29349 [Opn->Bgs]: imagecreatefromstring segfaults (fix included)

ID: 29349 Updated by: iliaa@php.net Reported By: k at ailis dot de -Status: Open +Status: Bogus Bug Type: GD related Operating System: Linux PHP Version: 4CVS-2004-07-23 (stable) New Comment: 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. Previous Comments: ------------------------------------------------------------------------ [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; ------------------------------------------------------------------------ [2004-07-24 14:08:46] adconrad at debian dot org Also note that gdNewDynamicCtx is used 3 times in gd.c, not just once as the patch would lead one to believe. ------------------------------------------------------------------------ [2004-07-24 14:05:05] adconrad at debian dot org Note that gdNewDynamicCtxEx was added in 2.0.21, so if this is used unconditionally, PHP will need to depend on that version of libgd2. (Also, this does appear to fix the segfaults being reported all over the place for imagecreatefromstring with the external libgd2) ------------------------------------------------------------------------ [2004-07-23 14:09:13] k at ailis dot de I have searched the closed bug reports and it looks like you will find the whole problem in #24174 (including a backtrace). Your solution was to modify the bundled GD library. In my opinion this is a very bad solution because this does not fix the problem if you use the external GD library. And it seems NOT to be a bug in GD! It's seems more like a misuse of a GD-function. The external GD library AND the bundled one can be used if you try my fix and check if it does not break something else. It looks to me that Boutell has created this *CtxEx function exactly for people who want to control the memory-freeing behaviour of the function so it might be the correct solution. ------------------------------------------------------------------------ [2004-07-23 13:50:20] tony2001@php.net Thank you for this bug report. To properly diagnose the problem, we need a backtrace to see what is happening behind the scenes. To find out how to generate a backtrace, please read http://bugs.php.net/bugs-generating-backtrace.php Once you have generated a backtrace, please submit it to this bug report and change the status back to "Open". Thank you for helping us make PHP better. Please, provide a gdb backtrace. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/29349 -- Edit this bug report at http://bugs.php.net/?id=29349&edit=1