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Date:   Thu, 17 Dec 2020 10:42:02 +0300
From:   Cyrill Gorcunov <gorcunov@gmail.com>
To:     Keno Fischer <keno@juliacomputing.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>, mkoutny@suse.com,
        ktkhai@virtuozzo.com
Subject: Re: brk checks in PR_SET_MM code
Message-ID: <20201217074202.GD14556@grain>
References: <CABV8kRwoHAAdez8k60O+AJ9E3g5_PM0F6tpbpB9dC115_FD3Eg@mail.gmail.com>
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On Wed, Dec 16, 2020 at 08:29:30PM -0500, Keno Fischer wrote:
> Hi all,
> 
> The code in prctl(PR_SET_MM, ...) performs a number of sanity checks,
> among them
> 
> ```
> /*
>  * @brk should be after @end_data in traditional maps.
>  */
> if (prctl_map->start_brk <= prctl_map->end_data ||
>     prctl_map->brk <= prctl_map->end_data)
> goto out;
> ```
> 

Thanks for pointing, Keno! I don't remember the details right now,
gimme some time and once I refresh my memory I'll reply with
details.