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Date:   Tue, 25 Sep 2018 19:37:45 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Tong Zhang <ztong@vt.edu>
Cc:     tglx@linutronix.de, akpm@linux-foundation.org,
        linux@dominikbrodowski.net, gorcunov@openvz.org,
        ebiederm@xmission.com, keescook@chromium.org, Dave.Martin@arm.com,
        wolffhardt.schwabe@fau.de, yang.shi@linux.alibaba.com,
        linux-kernel@vger.kernel.org, wenbo.s@samsung.com
Subject: Re: different capability from different namespace required for
 prctl_set_mm_exe_file
Message-ID: <20180925173745.GA20508@kroah.com>
References: <990D0DB4-35C7-4B7B-A938-2B984CD97E78@vt.edu>
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On Tue, Sep 25, 2018 at 01:26:55PM -0400, Tong Zhang wrote:
> Kernel Version: 4.18.5
> 
> Problem Description:
> 
> We discovered inconsistent check when using prctl_set_mm_exe_file(), which is used to setup exe file link.
> 
> It is required to have capable(CAP_SYS_RESOURCE) in prctl_set_mm().
> while ns_capable(CAP_SYS_ADMIN) in prctl_set_mm_map().
> 
> There are two differences:
> 1)requiring capability from: user namespace, init namespace.
> 2)capability bit required is different

Can you submit a patch showing what you think is the correct fix here?

thanks,

greg k-h