From: Pavel Machek <pavel@ucw.cz>
To: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>,
Dominik Brodowski <linux@dominikbrodowski.net>,
linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
kvm@vger.kernel.org, Heiko Carstens <heiko.carstens@de.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
David Hildenbrand <david@redhat.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jon Masters <jcm@redhat.com>, Marcus Meissner <meissner@suse.de>,
Jiri Kosina <jkosina@suse.cz>,
w@1wt.eu, keescook@chromium.org, thomas.lendacky@amd.com,
dwmw@amazon.co.uk, ak@linux.intel.com
Subject: Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]
Date: Mon, 29 Jan 2018 14:14:46 +0100 [thread overview]
Message-ID: <20180129131446.GB4669@amd> (raw)
In-Reply-To: <20180124204622.1f7b0de2@alans-desktop>
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On Wed 2018-01-24 20:46:22, Alan Cox wrote:
> > Anyway, no need to add prctl(), if A can ptrace B and B can ptrace A,
> > leaking info between them should not be a big deal. You can probably
> > find existing macros doing neccessary checks.
>
> Until one of them is security managed so it shouldn't be able to ptrace
> the other, or (and this is the nasty one) when a process is executing
> code it wants to protect from the rest of the same process (eg an
> untrusted jvm, javascript or probably nastiest of all webassembly)
>
> We don't need a prctl for trusted/untrusted IMHO but we do eventually
> need to think about API's for "this lot is me but I don't trust
> it" (flatpack, docker, etc) and for what JIT engines need to do.
Agreed.
And yes, JITs are interesting, and given the latest
rowhammer/sidechannel attacks, something we may want to limit in
future...
It sounds nice on paper but is just risky.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next prev parent reply other threads:[~2018-01-29 13:14 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-23 13:07 [RFC][PATCH 0/5] s390: improve speculative execution handling v2 Martin Schwidefsky
2018-01-23 13:07 ` [PATCH 1/5] prctl: add PR_ISOLATE_BP process control Martin Schwidefsky
2018-01-23 17:07 ` Dominik Brodowski
2018-01-24 6:29 ` Martin Schwidefsky
2018-01-24 8:37 ` Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control] Dominik Brodowski
2018-01-24 9:24 ` David Woodhouse
2018-01-24 11:15 ` Pavel Machek
2018-01-24 12:48 ` Martin Schwidefsky
2018-01-24 19:01 ` Pavel Machek
2018-01-24 20:46 ` Alan Cox
2018-01-29 13:14 ` Pavel Machek [this message]
2018-01-29 20:12 ` Alan Cox
2018-01-24 15:42 ` Alan Cox
2018-01-24 8:08 ` [PATCH 1/5] prctl: add PR_ISOLATE_BP process control Christian Borntraeger
2018-01-23 13:07 ` [PATCH 2/5] s390/alternative: use a copy of the facility bit mask Martin Schwidefsky
2018-01-23 13:59 ` Cornelia Huck
2018-01-23 14:40 ` Martin Schwidefsky
2018-01-23 15:04 ` Cornelia Huck
2018-01-23 13:07 ` [PATCH 3/5] s390: add options to change branch prediction behaviour for the kernel Martin Schwidefsky
2018-01-23 13:07 ` [PATCH 4/5] s390: define ISOLATE_BP to run tasks with modified branch prediction Martin Schwidefsky
2018-01-23 14:21 ` Christian Borntraeger
2018-01-23 20:32 ` Radim Krčmář
2018-01-24 6:36 ` Martin Schwidefsky
2018-01-24 11:50 ` Radim Krčmář
2018-01-23 13:07 ` [PATCH 5/5] s390: scrub registers on kernel entry and KVM exit Martin Schwidefsky
2018-01-23 13:09 ` Christian Borntraeger
2018-01-23 14:32 ` Martin Schwidefsky
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