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From: Greg KH <gregkh@linuxfoundation.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: tglx@linutronix.de, dwmw@amazon.co.uk,
	torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
	arjan.van.de.ven@intel.com, peterz@infradead.org,
	Andi Kleen <ak@linux.intel.com>,
	jeyu@kernel.org
Subject: Re: [PATCH] retpoline/module: Taint kernel for missing retpoline in module
Date: Sat, 13 Jan 2018 15:12:09 +0100	[thread overview]
Message-ID: <20180113141209.GA13015@kroah.com> (raw)
In-Reply-To: <20180112175507.31750-1-andi@firstfloor.org>

On Fri, Jan 12, 2018 at 09:55:07AM -0800, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> There's a risk that a kernel that has full retpoline mitigations
> becomes vulnerable when a module gets loaded that hasn't been
> compiled with the right compiler or the right option.
> 
> We cannot fix it, but should at least warn the user when that
> happens.
> 
> Add a flag to each module if it has been compiled with RETPOLINE
> 
> When the a module hasn't been compiled with a retpoline
> aware compiler, print a warning and set a taint flag.

Isn't that caught by the "build with a different compiler/version" check
that we have?  Or used to have?  If not, can't we just make it into that
type of check to catch this type of problem no matter what type of
feature/option it is trying to catch?

thanks,

greg k-h

  parent reply	other threads:[~2018-01-13 14:12 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-12 17:55 [PATCH] retpoline/module: Taint kernel for missing retpoline in module Andi Kleen
2018-01-12 19:01 ` David Woodhouse
2018-01-12 19:17   ` Andi Kleen
2018-01-13 14:12 ` Greg KH [this message]
2018-01-13 14:38   ` Van De Ven, Arjan
2018-01-13 15:37     ` Greg KH
2018-01-13 14:53   ` Andi Kleen
2018-01-13 15:36     ` Greg KH
2018-01-13 18:20       ` Andi Kleen
2018-01-16 20:08       ` Andi Kleen
2018-01-15 12:47 ` David Laight
2018-01-15 12:53   ` Van De Ven, Arjan
2018-01-15 13:01     ` David Woodhouse
2018-01-15 14:08       ` David Laight
2018-01-15 16:48   ` Andi Kleen

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