From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: Pavel Machek <pavel@ucw.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>,
tglx@linuxtronix.de,
Greg Kroah-Hartman <gregkh@linux-foundation.org>,
dwmw@amazon.co.uk, Tim Chen <tim.c.chen@linux.intel.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Dave Hansen <dave.hansen@intel.com>
Subject: Re: Avoid speculative indirect calls in kernel
Date: Thu, 4 Jan 2018 11:54:07 +0000 [thread overview]
Message-ID: <20180104115407.51e1c032@alans-desktop> (raw)
In-Reply-To: <20180104112614.GA1702@amd>
On Thu, 4 Jan 2018 12:26:14 +0100
Pavel Machek <pavel@ucw.cz> wrote:
> On Wed 2018-01-03 15:51:35, Linus Torvalds wrote:
> > On Wed, Jan 3, 2018 at 3:09 PM, Andi Kleen <andi@firstfloor.org> wrote:
> > > This is a fix for Variant 2 in
> > > https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html
> > >
> > > Any speculative indirect calls in the kernel can be tricked
> > > to execute any kernel code, which may allow side channel
> > > attacks that can leak arbitrary kernel data.
> >
> > Why is this all done without any configuration options?
> >
> > A *competent* CPU engineer would fix this by making sure speculation
> > doesn't happen across protection domains. Maybe even a L1 I$ that is
> > keyed by CPL.
>
> Would that be enough?
For the entire system - no. To start with the current most dangerous
attack is the javascript one. And that is an attack by a process on
itself. Likewise simply keying L1I by CPL wouldn't stop ring 3
processes attacking one another or deal with virtual machines properly.
For some of those cases (notably the JIT ones) it's quite probable that
there isn't enough information for the processor to even infer what is
needed.
Alan
next prev parent reply other threads:[~2018-01-04 11:54 UTC|newest]
Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-03 23:09 Avoid speculative indirect calls in kernel Andi Kleen
2018-01-03 23:09 ` [PATCH 01/11] x86/retpoline: Define retpoline indirect thunk and macros Andi Kleen
2018-01-03 23:09 ` [PATCH 02/11] x86/retpoline/crypto: Convert crypto assembler indirect jumps Andi Kleen
2018-01-03 23:09 ` [PATCH 03/11] x86/retpoline/entry: Convert entry " Andi Kleen
2018-01-03 23:09 ` [PATCH 04/11] x86/retpoline/ftrace: Convert ftrace " Andi Kleen
2018-01-03 23:09 ` [PATCH 05/11] x86/retpoline/hyperv: Convert " Andi Kleen
2018-01-03 23:09 ` [PATCH 06/11] x86/retpoline/crypto: Convert xen " Andi Kleen
2018-01-03 23:09 ` [PATCH 07/11] x86/retpoline/checksum32: Convert " Andi Kleen
2018-01-03 23:09 ` [PATCH 08/11] x86/retpoline/irq32: " Andi Kleen
2018-01-03 23:09 ` [PATCH 09/11] x86/retpoline: Finally enable retpoline for C code Andi Kleen
2018-01-04 8:28 ` Greg KH
2018-01-04 8:30 ` Dave Hansen
2018-01-03 23:09 ` [PATCH 10/11] retpoline/taint: Taint kernel for missing retpoline in compiler Andi Kleen
2018-01-04 0:29 ` Thomas Gleixner
2018-01-04 0:35 ` Randy Dunlap
2018-01-03 23:09 ` [PATCH 11/11] retpoline/objtool: Disable some objtool warnings Andi Kleen
2018-01-03 23:51 ` Avoid speculative indirect calls in kernel Linus Torvalds
2018-01-04 0:00 ` Alan Cox
2018-01-04 0:09 ` Andi Kleen
2018-01-04 0:12 ` Thomas Gleixner
2018-01-04 0:15 ` Andi Kleen
2018-01-04 0:19 ` Jiri Kosina
2018-01-05 2:01 ` james harvey
2018-01-05 10:40 ` Woodhouse, David
2018-01-05 12:29 ` james harvey
2018-01-05 12:06 ` Alan Cox
2018-01-04 0:29 ` Alan Cox
2018-01-04 0:31 ` Thomas Gleixner
2018-01-04 0:38 ` Alan Cox
2018-01-04 0:40 ` Andi Kleen
2018-01-04 8:15 ` Woodhouse, David
2018-01-04 15:53 ` Andi Kleen
2018-01-04 15:55 ` Woodhouse, David
2018-01-04 0:20 ` Linus Torvalds
2018-01-04 0:26 ` Thomas Gleixner
2018-01-04 0:18 ` David Lang
2018-01-04 1:00 ` Paul Turner
2018-01-04 1:41 ` Paolo Bonzini
2018-01-04 1:59 ` Alan Cox
2018-01-04 2:11 ` Paolo Bonzini
2018-01-04 8:20 ` Woodhouse, David
2018-01-04 11:42 ` Pavel Machek
2018-01-04 11:47 ` Woodhouse, David
2018-01-04 14:20 ` Paolo Bonzini
2018-01-04 14:51 ` Andrew Cooper
2018-01-04 15:29 ` Woodhouse, David
2018-01-04 15:32 ` Paolo Bonzini
2018-01-04 15:37 ` Andrew Cooper
2018-01-04 16:15 ` David Woodhouse
2018-01-04 20:00 ` Tom Lendacky
2018-01-04 20:05 ` David Woodhouse
2018-01-04 23:47 ` Tom Lendacky
2018-01-05 0:06 ` Andrew Cooper
2018-01-05 0:26 ` Tom Lendacky
2018-01-04 16:52 ` Andrea Arcangeli
2018-01-04 15:32 ` Paolo Bonzini
2018-01-04 16:25 ` Andrea Arcangeli
2018-01-04 17:04 ` Alan Cox
2018-01-04 17:40 ` Andrea Arcangeli
2018-01-04 17:13 ` Dave Hansen
2018-01-04 17:15 ` Paolo Bonzini
2018-01-04 18:05 ` Andrea Arcangeli
2018-01-04 14:55 ` Woodhouse, David
2018-01-04 18:24 ` Pavel Machek
2018-01-04 19:57 ` Jon Masters
2018-01-05 0:41 ` Jon Masters
2018-01-05 0:54 ` Thomas Gleixner
2018-01-05 4:11 ` Jon Masters
2018-01-05 9:59 ` Thomas Gleixner
2018-01-08 10:28 ` Andrea Arcangeli
2018-01-08 20:42 ` [tip:x86/pti] x86/tboot: Unbreak tboot with PTI enabled tip-bot for Dave Hansen
2018-01-08 20:53 ` Avoid speculative indirect calls in kernel Thomas Gleixner
2018-01-08 21:32 ` Andrea Arcangeli
2018-01-10 0:45 ` Thomas Gleixner
2018-01-10 1:11 ` Dave Hansen
2018-01-10 16:02 ` Thomas Gleixner
2018-01-05 6:49 ` Willy Tarreau
2018-01-05 6:57 ` Dave Hansen
2018-01-05 7:13 ` Willy Tarreau
2018-01-07 14:14 ` Borislav Petkov
2018-01-07 17:21 ` David Lang
2018-01-07 18:49 ` Borislav Petkov
2018-01-07 17:44 ` Willy Tarreau
2018-01-07 18:55 ` Borislav Petkov
2018-01-07 22:10 ` Willy Tarreau
2018-01-08 9:18 ` Thomas Gleixner
2018-01-08 9:29 ` Willy Tarreau
2018-01-08 16:22 ` Borislav Petkov
2018-01-08 16:53 ` Willy Tarreau
2018-01-05 12:12 ` Alan Cox
2018-01-09 1:44 ` Samir Bellabes
[not found] ` <CAL9bgJ8XNJgCtxR6+M+Vm9eDBVZ4Dyi_-Lt-Q1ei9N=TE2c6cg@mail.gmail.com>
2018-01-07 5:04 ` Fwd: " Kiernan Hager
2018-01-07 6:39 ` Willy Tarreau
2018-01-07 14:01 ` Alan Cox
2018-01-07 17:47 ` Willy Tarreau
2018-01-07 18:01 ` Ivan Ivanov
2018-01-07 18:16 ` Woodhouse, David
2018-01-04 11:26 ` Pavel Machek
2018-01-04 11:54 ` Alan Cox [this message]
2018-01-04 18:33 ` Linus Torvalds
2018-01-04 20:08 ` Jon Masters
-- strict thread matches above, loose matches on Subject: below --
2018-01-04 2:00 Andi Kleen
2018-01-04 11:49 ` Pavel Machek
2018-01-04 12:09 ` Alan Cox
2018-01-04 13:32 ` Pavel Machek
2018-01-12 8:20 Dr. Greg Wettstein
2018-02-23 21:10 Ywe Cærlyn
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180104115407.51e1c032@alans-desktop \
--to=gnomes@lxorguk.ukuu.org.uk \
--cc=andi@firstfloor.org \
--cc=dave.hansen@intel.com \
--cc=dwmw@amazon.co.uk \
--cc=gregkh@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=tglx@linuxtronix.de \
--cc=tim.c.chen@linux.intel.com \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox