linux-kernel - Re: Stackleak vs noinstr (Was: [GIT pull] objtool/core for v5.16-rc1)

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: <20211103081935.GA174703@worktop.programming.kicks-ass.net>
Date:   Wed, 3 Nov 2021 09:19:35 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Alexander Popov <alex.popov@...ux.com>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        the arch/x86 maintainers <x86@...nel.org>
Subject: Re: Stackleak vs noinstr (Was: [GIT pull] objtool/core for v5.16-rc1)

On Wed, Nov 03, 2021 at 10:18:22AM +0300, Alexander Popov wrote:
> Yes, this is a correct approach.
> 
> But I'm not sure about removing NOKPROBE_SYMBOL and notrace for
> stackleak_erase. Does the code in noinstr.text disable all those?

Yes, noinstr implies all those and more. Both kprobe and tracing are a
form of instrumentation, and hence noinstr must disallow it.