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Date:   Fri, 4 May 2018 11:49:28 +0100
From:   Mark Rutland <mark.rutland@arm.com>
To:     Daniel Borkmann <daniel@iogearbox.net>
Cc:     linux-kernel@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Peter Zijlstra <peterz@infradead.org>, netdev@vger.kernel.org
Subject: Re: [PATCH] bpf: fix possible spectre-v1 in find_and_alloc_map()
Message-ID: <20180504104927.qp4rwx6fuomdihov@lakrids.cambridge.arm.com>
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On Fri, May 04, 2018 at 02:16:31AM +0200, Daniel Borkmann wrote:
> On 05/03/2018 06:04 PM, Mark Rutland wrote:
> > It's possible for userspace to control attr->map_type. Sanitize it when
> > using it as an array index to prevent an out-of-bounds value being used
> > under speculation.
> > 
> > Found by smatch.
> > 
> > Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> > Cc: Alexei Starovoitov <ast@kernel.org>
> > Cc: Dan Carpenter <dan.carpenter@oracle.com>
> > Cc: Daniel Borkmann <daniel@iogearbox.net>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: netdev@vger.kernel.org
> 
> Applied to bpf tree, thanks Mark!

Cheers!

> I've also just submitted one for BPF progs
> (http://patchwork.ozlabs.org/patch/908385/) which is same situation.

That looks good to me. That case doesn't show up in my smatch results so
far, but I might just need a few more build iterations.

Thanks,
Mark.