From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Andy Lutomirski <luto@amacapital.net>,
Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "security@kernel.org" <security@kernel.org>,
Peter Zijlstra <peterz@infradead.org>, X86 ML <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
xen-devel <xen-devel@lists.xen.org>,
Borislav Petkov <bp@alien8.de>, Jan Beulich <jbeulich@suse.com>,
Sasha Levin <sasha.levin@oracle.com>
Subject: Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option
Date: Tue, 28 Jul 2015 13:10:41 -0400 [thread overview]
Message-ID: <55B7B791.2050208@oracle.com> (raw)
In-Reply-To: <CALCETrVd56uwkZw0YtaSHKHp5dh7NugQouigibJkr=e3Q_mYyA@mail.gmail.com>
On 07/28/2015 01:07 PM, Andy Lutomirski wrote:
> On Tue, Jul 28, 2015 at 9:30 AM, Andrew Cooper
> <andrew.cooper3@citrix.com> wrote:
>> I suspect that the set_ldt(NULL, 0) call hasn't reached Xen before
>> xen_free_ldt() is attempting to nab back the pages which Xen still has
>> mapped as an LDT.
>>
> I just instrumented it with yet more LSL instructions. I'm pretty
> sure that set_ldt really is clearing at least LDT entry zero.
> Nonetheless the free_ldt call still oopses.
>
Yes, I added some instrumentation to the hypervisor and we definitely
set LDT to NULL before failing.
-boris
next prev parent reply other threads:[~2015-07-28 17:12 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-25 5:36 Andy Lutomirski
2015-07-25 5:36 ` [PATCH v4 1/3] x86/ldt: Make modify_ldt synchronous Andy Lutomirski
2015-07-25 9:03 ` Borislav Petkov
2015-07-25 5:36 ` [PATCH v4 2/3] x86/ldt: Make modify_ldt optional Andy Lutomirski
2015-07-25 6:23 ` Willy Tarreau
2015-07-25 6:44 ` Andy Lutomirski
2015-07-25 7:50 ` Willy Tarreau
2015-07-25 13:03 ` [PATCH 4/3] x86/ldt: allow to disable modify_ldt at runtime Willy Tarreau
2015-07-25 16:08 ` Andy Lutomirski
2015-07-25 16:33 ` Willy Tarreau
2015-07-25 17:42 ` Andy Lutomirski
2015-07-25 18:45 ` Willy Tarreau
2015-07-27 19:04 ` Kees Cook
2015-07-27 21:37 ` Willy Tarreau
2015-07-25 9:15 ` [PATCH v4 2/3] x86/ldt: Make modify_ldt optional Borislav Petkov
2015-07-25 16:03 ` Andy Lutomirski
2015-07-25 16:35 ` Willy Tarreau
2015-07-25 5:36 ` [PATCH v4 3/3] selftests/x86, x86/ldt: Add a selftest for modify_ldt Andy Lutomirski
2015-07-27 15:52 ` [PATCH v4.1 3.3] " Andy Lutomirski
2015-07-25 6:27 ` [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option Willy Tarreau
2015-07-27 15:36 ` Boris Ostrovsky
2015-07-27 15:53 ` Andy Lutomirski
2015-07-27 16:18 ` Boris Ostrovsky
2015-07-28 2:20 ` Andy Lutomirski
2015-07-28 3:16 ` Andy Lutomirski
2015-07-28 3:23 ` Andy Lutomirski
2015-07-28 3:43 ` Boris Ostrovsky
2015-07-28 10:29 ` Andrew Cooper
2015-07-28 14:05 ` Boris Ostrovsky
2015-07-28 14:35 ` Andrew Cooper
2015-07-28 14:50 ` Boris Ostrovsky
2015-07-28 15:15 ` Konrad Rzeszutek Wilk
2015-07-28 15:39 ` Boris Ostrovsky
2015-07-28 15:23 ` Andrew Cooper
2015-07-28 15:59 ` [Xen-devel] " Boris Ostrovsky
2015-07-28 15:43 ` Andy Lutomirski
2015-07-28 16:30 ` Andrew Cooper
2015-07-28 17:07 ` Andy Lutomirski
2015-07-28 17:10 ` Boris Ostrovsky [this message]
2015-07-29 0:21 ` [Xen-devel] " Andy Lutomirski
2015-07-29 0:47 ` Andrew Cooper
2015-07-29 3:01 ` Boris Ostrovsky
2015-07-29 4:26 ` Andy Lutomirski
2015-07-29 5:28 ` Andy Lutomirski
2015-07-29 14:21 ` Andrew Cooper
2015-07-29 14:43 ` Boris Ostrovsky
2015-07-29 19:03 ` Andrew Cooper
2015-07-29 21:23 ` Boris Ostrovsky
2015-07-29 21:26 ` Andy Lutomirski
2015-07-29 21:33 ` Boris Ostrovsky
2015-07-29 21:37 ` Andrew Cooper
2015-07-29 22:05 ` Andy Lutomirski
2015-07-29 22:11 ` Andrew Cooper
2015-07-29 22:40 ` Boris Ostrovsky
2015-07-29 22:46 ` David Vrabel
2015-07-29 22:49 ` Boris Ostrovsky
2015-07-29 22:55 ` David Vrabel
2015-07-29 23:02 ` Andrew Cooper
2015-07-29 23:13 ` Andy Lutomirski
2015-07-30 0:29 ` Andrew Cooper
2015-07-30 18:30 ` Andy Lutomirski
2015-07-30 18:54 ` Andrew Cooper
2015-07-30 20:01 ` Boris Ostrovsky
2015-07-30 20:05 ` Andy Lutomirski
2015-07-30 20:18 ` Boris Ostrovsky
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