From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Brian Gerst <brgerst@gmail.com>,
Chris Metcalf <cmetcalf@mellanox.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Huang Rui <ray.huang@amd.com>, Jiri Slaby <jslaby@suse.cz>,
Jonathan Corbet <corbet@lwn.net>,
"Michael S. Tsirkin" <mst@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Vlastimil Babka <vbabka@suse.cz>, Chen Yucong <slaoub@gmail.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Shuah Khan <shuah@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
X86 ML <x86@kernel.org>, "Neri, Ricardo" <ricardo.neri@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-arch <linux-arch@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [PATCH v9 02/29] x86/boot: Relocate definition of the initial state of CR0
Date: Fri, 27 Oct 2017 12:02:19 -0700 [thread overview]
Message-ID: <20171027190219.GA7057@voyager> (raw)
In-Reply-To: <20171026125513.GB12068@nazgul.tnic>
On Thu, Oct 26, 2017 at 02:55:13PM +0200, Borislav Petkov wrote:
> On Thu, Oct 26, 2017 at 02:02:02AM -0700, Andy Lutomirski wrote:
> > I'm assuming that UMIP_REPORTED_CR0 will never change. If CR0 gets a
> > new field that we set some day, then I assume that CR0_STATE would add
> > that bit but UMIP_REPORTED_CR0 would not.
>
> Yeah, let's do that when it is actually needed.
Thanks Andy! I reasoned that for UMIP could report CR0_STATE a value that
is already revealed in the source code. Thus, if CR0 ever changes at run
time, an attacker could only see what is set programmatically.
BR,
Ricardo
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prev parent reply other threads:[~2017-10-27 19:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1507089272-32733-1-git-send-email-ricardo.neri-calderon@linux.intel.com>
2017-10-04 3:54 ` [PATCH v9 02/29] x86/boot: Relocate definition of the initial state of CR0 Ricardo Neri
2017-10-26 7:51 ` Andy Lutomirski
2017-10-26 9:00 ` Borislav Petkov
2017-10-26 9:02 ` Andy Lutomirski
2017-10-26 12:55 ` Borislav Petkov
2017-10-27 19:02 ` Ricardo Neri [this message]
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