From: Peter Zijlstra <peterz@infradead.org>
To: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: scott.d.constable@intel.com, daniel.sneddon@linux.intel.com,
Jakub Kicinski <kuba@kernel.org>,
dave.hansen@intel.com, Johannes Berg <johannes@sipsolutions.net>,
Paolo Abeni <pabeni@redhat.com>,
antonio.gomez.iglesias@linux.intel.com,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
x86@kernel.org, gregkh@linuxfoundation.org,
netdev@vger.kernel.org
Subject: Re: [RFC PATCH 0/2] Branch Target Injection (BTI) gadget in minstrel
Date: Tue, 25 Oct 2022 22:31:00 +0200 [thread overview]
Message-ID: <Y1hHhMczQlqi4DxD@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20221025193845.z7obsqotxi2yiwli@desk>
On Tue, Oct 25, 2022 at 12:38:45PM -0700, Pawan Gupta wrote:
> > I think the focus should be on finding the source sites, not protecting
> > the target sites. Where can an attacker control the register content and
> > have an indirect jump/call.
>
> That is an interesting approach. I am wondering what mitigation can
> be applied at source?
Limiting the value ranges for example. Or straight up killing the values
if they go unused -- like how we clear the registers in entry.
> LFENCE before an indirect branch can greatly
> reduce the speculation window, but will not completely eliminate it.
Depends on the part; there's a whole bunch of parts where LFENCE is
sufficient.
next prev parent reply other threads:[~2022-10-25 20:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-24 22:57 [RFC PATCH 0/2] Branch Target Injection (BTI) gadget in minstrel Pawan Gupta
2022-10-24 22:57 ` [RFC PATCH 1/2] nospec: Add a generic barrier_nospec() Pawan Gupta
2022-10-24 22:57 ` [RFC PATCH 2/2] minstrel_ht: Mitigate BTI gadget minstrel_ht_get_expected_throughput() Pawan Gupta
2022-10-25 7:36 ` Greg KH
2022-10-25 16:55 ` Pawan Gupta
2022-10-25 11:07 ` [RFC PATCH 0/2] Branch Target Injection (BTI) gadget in minstrel Peter Zijlstra
2022-10-25 19:38 ` Pawan Gupta
2022-10-25 19:56 ` Johannes Berg
2022-10-26 0:17 ` Pawan Gupta
2022-10-25 20:31 ` Peter Zijlstra [this message]
2022-10-25 22:00 ` Dave Hansen
2022-10-26 7:31 ` Peter Zijlstra
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