On Wed, May 28, 2014 at 12:53 AM, Ralph Seichter roundcube.net@sentries.org wrote:
Let's not dwell on this. ;-) I can offer something more related to the problem at hand anyway. Lo and behold: the errors seem to be related to the type of file I want to attach. No matter the OPcache settings, I can successfully attach PDF files, but other file types (i.e. JPG, PNG, TXT) cause the Apache child process deaths. For example, I can attach foo.pdf without problems, but if I rename the file to foo.png, I see crashes. So far I could not find anything related to the file sizes.
Could the problem be rooted in the way Roundcube, PHP 5.5 and Apache 2.4 are handling different MIME types? There is no virus checker involved who could choke on different file types, so what could it be?
That strongly indicates that the mime detection using libmime seems to fail on your machine. We learned that the mimetypes submitted by the client cannot be trusted and therefore attempt to detect the mimetype of the uploaded file on the server. That's done in the following method using whatever functions and modules PHP offers: https://github.com/roundcube/roundcubemail/blob/master/program/lib/Roundcube...
Maybe you can do some tests with finfo_open() / finfo_file() and mime_content_type() do further track down the failing component.
Kind regards, Thomas