From: Theodore Ts'o <tytso@mit.edu>
To: Avi Kivity <avi@scylladb.com>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: Proposal: CAP_PAYLOAD to reduce Meltdown and Spectre mitigation costs
Date: Sun, 7 Jan 2018 07:29:18 -0500 [thread overview]
Message-ID: <20180107122918.GE2404@thunk.org> (raw)
In-Reply-To: <dc3d9f6b-248e-a201-004f-43d99bc7ada0@scylladb.com>
On Sun, Jan 07, 2018 at 11:16:28AM +0200, Avi Kivity wrote:
> I think capabilities will work just as well with cgroups. The container
> manager will set CAP_PAYLOAD to payload containers; and if those run an init
> system or a container manager themselves, they'll drop CAP_PAYLOAD for all
> process/sub-containers but their payloads.
The reason why cgroups are better is Spectre can be used to steal
information from within the same privilege level --- e.g., you could
use Javascript to steal a user's Coindesk credentials or Lastpass
data, which is going to be *way* more lucrative than trying to mine
cryptocurrency in the sly in a user's browser. :-)
As a result, you probably want Spectre mitigations to be enabled in a
root process --- which means capabilities aren't the right answer.
Regards,
- Ted
next prev parent reply other threads:[~2018-01-07 12:29 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-06 19:33 Proposal: CAP_PAYLOAD to reduce Meltdown and Spectre mitigation costs Avi Kivity
2018-01-06 20:02 ` Alan Cox
2018-01-07 9:16 ` Avi Kivity
2018-01-07 12:29 ` Theodore Ts'o [this message]
2018-01-07 12:34 ` Ozgur
2018-01-07 12:51 ` Avi Kivity
2018-01-07 18:06 ` Theodore Ts'o
2018-01-06 20:24 ` Willy Tarreau
2018-01-07 9:14 ` Avi Kivity
2018-01-07 17:39 ` Willy Tarreau
2018-01-07 14:36 ` Alan Cox
2018-01-07 15:15 ` Avi Kivity
2018-01-07 17:26 ` Willy Tarreau
2018-01-08 1:33 ` Casey Schaufler
2018-01-08 1:33 ` Casey Schaufler
2018-01-18 22:49 ` Pavel Machek
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