Subject: Re: bug#29249: 11.91; Formulae are no longer shown with preview LaTeX

From: David Kastrup <[email-masked]>
Date: Fri, 10 Nov 2017 17:56:04 +0100

"Dr. Michael L. Dowling" <[email-masked]> writes:

> Output from running `/usr/bin/rungs -h':
> GPL Ghostscript 9.22 (2017-10-04)
> Copyright (C) 2017 Artifex Software, Inc.  All rights reserved.

Gnuscript developers have decided to remove the .runandhide operator
(the only available and documented mechanism for entering SAFER mode
temporarily and safely) in Ghostscript 9.22.  I have committed a fix to
AUCTeX master that removes all uses of .runandhide from preview-latex
(preview-latex already had been changed previously to not require
returning from SAFER mode, so this change is not security-relevant).

I haven't heard back from any of the current AUCTeX
developers/maintainers so I have no idea when this fix will actually
make it into a release.

You might want to either apply this recent commit in the AUCTeX
repository to your AUCTeX distribution (it's

commit 837d590008c1dd4e92ffbce15008efb761d11f7c
Author: David Kastrup <[email-masked]>
Date:   Mon Nov 6 23:58:23 2017 +0100

    Remove use of .runandhide operator
    
    Ghostscript bug 698680
    <https://bugs.ghostscript.com/show_bug.cgi?id=698680> has been caused
    by the removal of the .runandhide operator in Ghostscript 9.22
    upstream.  Since .runandhide has no longer been used in a
    security-critical manner, its operation can be emulated by storing the
    respective information in a .preview-ST variable.  Potentially
    malicious code would not be able to retrieve a non-safe "save" object
    from here.

) or downgrade your Ghostscript to 9.21.

You sent a humongous mail of 12MB size to the AUCTeX bug list: I'll
reject that mail since it adds nothing new.

-- 
David Kastrup