linux-kernel - Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CALCETrXDF2c2-gnOyNTnEn-uPAZp0AaSB_PB8e2y8jf7zo=Cyg@mail.gmail.com>
Date:   Tue, 26 Mar 2019 12:20:24 -0700
From:   Andy Lutomirski <luto@...nel.org>
To:     Matthew Garrett <matthewgarrett@...gle.com>
Cc:     James Morris <jmorris@...ei.org>,
        LSM List <linux-security-module@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        David Howells <dhowells@...hat.com>,
        Linux API <linux-api@...r.kernel.org>,
        Andrew Lutomirski <luto@...nel.org>,
        Matthew Garrett <mjg59@...gle.com>,
        Greg KH <gregkh@...uxfoundation.org>
Subject: Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

On Tue, Mar 26, 2019 at 11:28 AM Matthew Garrett
<matthewgarrett@...gle.com> wrote:
>
> From: Matthew Garrett <mjg59@...gle.com>
>
> debugfs has not been meaningfully audited in terms of ensuring that
> userland cannot trample over the kernel. At Greg's request, disable
> access to it entirely when the kernel is locked down. This is done at
> open() time rather than init time as the kernel lockdown status may be
> made stricter at runtime.

Ugh.  Some of those files are very useful.  Could this perhaps still
allow O_RDONLY if we're in INTEGRITY mode?