linux-kernel - RE: [PATCH] LDT improvements

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: <77ea98ade5ee40788c0a1b5d62b2d3e2@AcuMS.aculab.com>
Date:   Fri, 8 Dec 2017 17:29:08 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Andy Lutomirski' <luto@...nel.org>
CC:     Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>, Borislav Petkov <bp@...en8.de>,
        X86 ML <x86@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Brian Gerst <brgerst@...il.com>,
        Kees Cook <keescook@...omium.org>
Subject: RE: [PATCH] LDT improvements

From: Andy Lutomirski
> Sent: 08 December 2017 16:48
...
> I mean: if the user CS or SS is not accessed and the LDT is RO, then
> we get #PF on the IRET instruction, I think.  Dealing with that is
> truly awful.

Any fault in-kernel on the IRET is horrid.
Doesn't really matter which one.
Same goes for the 'pop %ds' (etc) that tend to precede it.

	David