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Date: Tue, 26 Nov 2013 19:09:41 +0100
From: Oleg Nesterov <oleg@redhat.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>, stable@vger.kernel.org
Subject: Re: [PATCH 2/4] x86: Fix the hw_breakpoint range check
Message-ID: <20131126180941.GA18542@redhat.com>
References: <1385289171-3411-1-git-send-email-fweisbec@gmail.com> <1385289171-3411-3-git-send-email-fweisbec@gmail.com> <20131124134057.GA4531@pd.tnic> <20131125195028.GA10127@redhat.com> <20131125201134.GK6782@pd.tnic>
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On 11/25, Borislav Petkov wrote:
>
> On Mon, Nov 25, 2013 at 08:50:28PM +0100, Oleg Nesterov wrote:
> > This won't work if va + len overflows?
>
> Oh, right,
>
> > Perhaps we should makes this clear, and we can even check the overflow
> > in the generic code (iirc Linus suggested to do this).
>
> maybe something like
>
> 	((va + len - 1) >= TASK_SIZE) || ((va + len - 1) < va)

Yes. But again, it makes sense to do this in the caller. And kill
the stupid get_hbp_len(). And other cleanups.

But this patch just tries to fix the typo in the security check.

Oleg.