linux-kernel - Re: [PATCH] powerpc/uaccess: Perform barrier

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] [day] [month] [year] [list]

Message-Id: <161296172412.3178259.4318567757525360600.b4-ty@ellerman.id.au>
Date:   Wed, 10 Feb 2021 23:57:27 +1100 (AEDT)
From:   Michael Ellerman <patch-notifications@...erman.id.au>
To:     Michael Ellerman <mpe@...erman.id.au>, cmr@...efail.de,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Paul Mackerras <paulus@...ba.org>
Cc:     linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] powerpc/uaccess: Perform barrier_nospec() in KUAP allowance helpers

On Sun, 7 Feb 2021 10:08:11 +0000 (UTC), Christophe Leroy wrote:
> barrier_nospec() in uaccess helpers is there to protect against
> speculative accesses around access_ok().
> 
> When using user_access_begin() sequences together with
> unsafe_get_user() like macros, barrier_nospec() is called for
> every single read although we know the access_ok() is done
> onece.
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/uaccess: Perform barrier_nospec() in KUAP allowance helpers
      https://git.kernel.org/powerpc/c/8524e2e76441fc615a3b5c1415823e051cc79eae

cheers