From: 'Pawan Gupta' <pawan.kumar.gupta@linux.intel.com>
To: David Laight <David.Laight@aculab.com>
Cc: Borislav Petkov <bp@alien8.de>, Jonathan Corbet <corbet@lwn.net>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"x86@kernel.org" <x86@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
"tony.luck@intel.com" <tony.luck@intel.com>,
"antonio.gomez.iglesias@linux.intel.com"
<antonio.gomez.iglesias@linux.intel.com>,
Daniel Sneddon <daniel.sneddon@linux.intel.com>,
"andrew.cooper3@citrix.com" <andrew.cooper3@citrix.com>,
Josh Poimboeuf <jpoimboe@kernel.org>
Subject: Re: [RESEND RFC PATCH] x86/bugs: Add "unknown" reporting for MMIO Stale Data
Date: Fri, 29 Jul 2022 10:45:21 -0700 [thread overview]
Message-ID: <20220729174521.kvbudqlpsoyvxzrv@desk> (raw)
In-Reply-To: <e7ba00885fca4ec9849d8525cbc46f7b@AcuMS.aculab.com>
On Fri, Jul 29, 2022 at 10:40:20AM +0000, David Laight wrote:
> From: Pawan Gupta
> > Sent: 29 July 2022 03:29
> >
> > On Thu, Jul 28, 2022 at 02:00:13PM +0200, Borislav Petkov wrote:
> > > On Thu, Jul 14, 2022 at 06:30:18PM -0700, Pawan Gupta wrote:
> > > > Older CPUs beyond its Servicing period are not listed in the affected
> > > > processor list for MMIO Stale Data vulnerabilities. These CPUs currently
> > > > report "Not affected" in sysfs, which may not be correct.
>
> I looked this up....
>
> The mitigations seem to rely on unprivileged code not being able
> to do MMIO accesses.
> That isn't true, device drivers can mmap PCIe addresses directly
> into user program address space.
> While unlikely, there is no reason this can't be supported for
> non-root processes.
Agree. Would it be fair to assume that processes that get direct
hardware access are trusted?
next prev parent reply other threads:[~2022-07-29 17:45 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-15 1:30 [RESEND RFC PATCH] x86/bugs: Add "unknown" reporting for MMIO Stale Data Pawan Gupta
2022-07-28 1:29 ` Pawan Gupta
2022-07-28 12:00 ` Borislav Petkov
2022-07-29 2:28 ` Pawan Gupta
2022-07-29 10:40 ` David Laight
2022-07-29 17:45 ` 'Pawan Gupta' [this message]
2022-07-29 14:05 ` Borislav Petkov
2022-07-29 17:36 ` Pawan Gupta
2022-07-29 20:30 ` Borislav Petkov
2022-07-29 21:46 ` Pawan Gupta
2022-07-29 22:02 ` Borislav Petkov
2022-07-30 2:31 ` Pawan Gupta
2022-07-29 22:54 ` Dave Hansen
2022-07-29 23:07 ` Tony Luck
2022-07-29 23:18 ` Dave Hansen
2022-07-30 2:40 ` Pawan Gupta
2022-07-28 19:08 ` Dave Hansen
2022-07-29 17:59 ` Pawan Gupta
2022-07-29 18:02 ` Dave Hansen
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