linux-kernel - Re: [RFC][PATCH 13/24] x86/pti: Extend PTI user mappings

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]

Date:   Mon, 9 Nov 2020 09:28:01 -0800
From:   Andy Lutomirski <luto@...capital.net>
To:     Alexandre Chartre <alexandre.chartre@...cle.com>
Cc:     X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [RFC][PATCH 13/24] x86/pti: Extend PTI user mappings

On Mon, Nov 9, 2020 at 3:22 AM Alexandre Chartre
<alexandre.chartre@...cle.com> wrote:
>
> Extend PTI user mappings so that more kernel entry code can be executed
> with the user page-table. To do so, we need to map syscall and interrupt
> entry code,

Probably fine.

> per cpu offsets (__per_cpu_offset, which is used some in
> entry code),

This likely already leaks due to vulnerable CPUs leaking address space
layout info.

> the stack canary,

That's going to be a very tough sell.