From: Borislav Petkov <bp@suse.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: yalin wang <yalin.wang2010@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
mingo@redhat.com, x86@kernel.org,
open list <linux-kernel@vger.kernel.org>,
Will Deacon <will.deacon@arm.com>
Subject: Re: [x86] copy_from{to}_user question
Date: Fri, 21 Aug 2015 06:35:52 +0200 [thread overview]
Message-ID: <20150821043552.GA29712@nazgul.tnic> (raw)
In-Reply-To: <55D61AF3.4090004@zytor.com>
On Thu, Aug 20, 2015 at 11:22:43AM -0700, H. Peter Anvin wrote:
> There is a valid reason to do this, which is that currently
> copy_{to,from}_user() effectively bypass SMAP as they don't verify that
> the kernel pointer is actually a kernel pointer.
Well, we do STAC before we copy but SMAP is checking for supervisor
access to *user* data. But you say "kernel pointers" which is supervisor
data. What am I missing?
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--
next prev parent reply other threads:[~2015-08-21 4:35 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-12 9:01 [x86] copy_from{to}_user question yalin wang
2015-08-12 10:07 ` Borislav Petkov
2015-08-13 10:04 ` yalin wang
2015-08-13 16:43 ` Borislav Petkov
2015-08-17 3:27 ` yalin wang
2015-08-17 4:16 ` Borislav Petkov
2015-08-20 8:58 ` yalin wang
2015-08-20 18:22 ` H. Peter Anvin
2015-08-21 4:35 ` Borislav Petkov [this message]
2015-08-21 21:06 ` H. Peter Anvin
2015-08-22 9:05 ` Borislav Petkov
2015-08-24 7:52 ` yalin wang
2015-08-24 12:05 ` Jeff Epler
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