linux-kernel - Re: [PATCH] Documentation/tracing: Mention that RESET_ATTACK

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20241001085326.5841a9ce@gandalf.local.home>
Date: Tue, 1 Oct 2024 08:53:26 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: Ard Biesheuvel <ardb@...nel.org>
Cc: Hans de Goede <hdegoede@...hat.com>, LKML
 <linux-kernel@...r.kernel.org>, Linux trace kernel
 <linux-trace-kernel@...r.kernel.org>, Masami Hiramatsu
 <mhiramat@...nel.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
 Mike Rapoport <mike.rapoport@...il.com>, Kees Cook <keescook@...omium.org>,
 Jonathan Corbet <corbet@....net>
Subject: Re: [PATCH] Documentation/tracing: Mention that
 RESET_ATTACK_MITIGATION can clear memory

On Tue, 1 Oct 2024 11:35:53 +0200
Ard Biesheuvel <ardb@...nel.org> wrote:

> All I am asking for is a line in the documentation that says that
> clobbered trace buffers could occur at any time, regardless of whether
> CONFIG_RESET_ATTACK_MITIGATION is enabled or not. That way, we have
> something to refer to when people start filing bugs against the EFI
> component when this breaks.

How about if I change the comment to this?

        Note, saving the trace buffer across reboots does require that the system
        is set up to not wipe memory. For instance, CONFIG_RESET_ATTACK_MITIGATION
        can force a memory reset on boot which will clear any trace that was stored.
        This is just one of many ways that can clear memory. Make sure your system
        keeps the content of memory across reboots before relying on this option.

Would that be better?

I want to stress that this doesn't work for every setup. It just so happens
to work for mine and others. I do not want people thinking that it's a bug
if it doesn't work for them.

-- Steve