linux-kernel - Re: [RFC] call_with

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: <20180718212205.GY30522@ZenIV.linux.org.uk>
Date:   Wed, 18 Jul 2018 22:22:05 +0100
From:   Al Viro <viro@...IV.linux.org.uk>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Miklos Szeredi <mszeredi@...hat.com>,
        Stephen Rothwell <sfr@...b.auug.org.au>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [RFC] call_with_creds()

On Wed, Jul 18, 2018 at 01:43:00PM -0700, Linus Torvalds wrote:

> What I really think I'd prefer is to have some simple way to "poison"
> current_cred().  It could be something as simple as a per-thread
> counter, and we'd have current_cred() do
> 
>         WARN_ON_ONCE(in_interrupt() || current->cred_poison);

Why is counter any better than LSB of a pointer?