#34704 [Opn->Fbk]: Infinite recursion due to corrupt JPEG

ID: 34704 Updated by: sniper@php.net Reported By: t dot starling at physics dot unimelb dot edu dot au -Status: Open +Status: Feedback Bug Type: EXIF related Operating System: linux PHP Version: 4.4.0 New Comment: Please try using this CVS snapshot: http://snaps.php.net/php5-latest.tar.gz For Windows: http://snaps.php.net/win32/php5-win32-latest.zip Previous Comments: ------------------------------------------------------------------------ [2005-10-02 09:07:14] t dot starling at physics dot unimelb dot edu dot au Description: ------------ An image, seen in the wild and probably generated non-maliciously, reliably causes exif_read_data() to go into infinite recursion. I've fixed the problem and created a patch against PHP 4.4.0: http://wikimedia.org/~tstarling/php/exif_IFD2.patch The test image is here: http://wikimedia.org/~tstarling/php/Carcraftbuckett.jpg The problem was an assumption that images would follow the spec and include a maximum of 2 IFD headers, IFD0 for the image and IFD1 for the thumbnail. The test image probably has the "next IFD offset" field pointing back to the same structure, creating an infinite loop. I haven't studied the test image in detail, but my patch allows PHP's Exif functions to read it without segfaulting, which is good enough for me. I decided to ignore any further IFDs beyond the first two rather than issue an error, for compatibility with possible future revisions of the Exif spec. -- Tim Starling (MediaWiki developer) ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=34704&edit=1