linux-kernel - Re: [PATCH 1/2] x86/intel_rdt: Check monitor group vs control group membership earlier

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: <613d0854-597e-6ed7-05ca-70310c7b887d@arm.com>
Date:   Fri, 20 Nov 2020 14:53:15 +0000
From:   James Morse <james.morse@....com>
To:     Valentin Schneider <valentin.schneider@....com>
Cc:     linux-kernel@...r.kernel.org, x86@...nel.org,
        Fenghua Yu <fenghua.yu@...el.com>,
        Reinette Chatre <reinette.chatre@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH 1/2] x86/intel_rdt: Check monitor group vs control group
 membership earlier

Hi Valentin,

On 18/11/2020 18:00, Valentin Schneider wrote:
> A task can only be moved between monitor groups if both groups belong to
> the same control group. This is checked fairly late however: by that time
> we already have appended a task_work() callback.

(is that a problem? It's needed to do the kfree())


> Check the validity of the move before getting anywhere near task_work
> callbacks.

This saves the kzalloc()/task_work_add() if it wasn't going to be necessary.

Reviewed-by: James Morse <james.morse@....com>


Thanks,

James