From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Jon Masters <jcm@redhat.com>,
"Woodhouse, David" <dwmw@amazon.co.uk>,
Paolo Bonzini <pbonzini@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>,
Greg Kroah-Hartman <gregkh@linux-foundation.org>,
Tim Chen <tim.c.chen@linux.intel.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Dave Hansen <dave.hansen@intel.com>, Jeff Law <law@redhat.com>,
Nick Clifton <nickc@redhat.com>
Subject: Re: Avoid speculative indirect calls in kernel
Date: Fri, 5 Jan 2018 12:12:41 +0000 [thread overview]
Message-ID: <20180105121241.497742f7@alans-desktop> (raw)
In-Reply-To: <alpine.DEB.2.20.1801050153290.2127@nanos>
On Fri, 5 Jan 2018 01:54:13 +0100 (CET)
Thomas Gleixner <tglx@linutronix.de> wrote:
> On Thu, 4 Jan 2018, Jon Masters wrote:
> > P.S. I've an internal document where I've been tracking "nice to haves"
> > for later, and one of them is whether it makes sense to tag binaries as
> > "trusted" (e.g. extended attribute, label, whatever). It was something I
> > wanted to bring up at some point as potentially worth considering.
>
> Scratch that. There is no such thing as a trusted binary.
There is if you are using signing and the like. I'm sure SELiux and
friends will grow the ability to set per process policy but that's
certainly not a priority.
However the question is wrong. 'trusted' is a binary operator not a unary
one.
The question that matters is
If I am executing A and about to switch to B does B trust A
because if B trusts A (which in Linuxspeak is 'can A ptrace B') then
there's not much point worrying about protection between them because what
you are trying to prevent is already expressly permitted.
It's even more important if there is a cost to the barrier imposition
because not only can you skip it sometimes but your scheduler can
schedule considering that cost just as it does cache eviction costs.
Alan
next prev parent reply other threads:[~2018-01-05 12:13 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 [this message]
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
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
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