linux-kernel - Re: [PATCH 0/3] arm64:msr: Add MSR driver

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: <20201201152552.GD22927@zn.tnic>
Date:   Tue, 1 Dec 2020 16:25:52 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Rongwei Wang <rongwei.wang@...ux.alibaba.com>
Cc:     catalin.marinas@....com, Will Deacon <will@...nel.org>,
        bjorn.andersson@...aro.org, shawnguo@...nel.org, vkoul@...nel.org,
        geert+renesas@...der.be, Anson.Huang@....com, michael@...le.cc,
        krzk@...nel.org, olof@...om.net, vincenzo.frascino@....com,
        ardb@...nel.org, masahiroy@...nel.org, gshan@...hat.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/3] arm64:msr: Add MSR driver

On Tue, Dec 01, 2020 at 11:17:39PM +0800, Rongwei Wang wrote:
> In ARM, the system registers can only be accessed through msr and mrs,
> so the problem created by MSR driver (depend on rdmsr and wrmsr) in
> x86 is not necessarily present in ARM, which is very different from
> x86.

No, the point I'm making is that it doesn't matter what the architecture
does or does not, register *writes* from userspace are a bad bad idea
for the reasons I described.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette