linux-mips
[Top] [All Lists]

Re: [PATCH v7 4/9] seccomp: move no_new_privs into seccomp

To: Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH v7 4/9] seccomp: move no_new_privs into seccomp
From: Andy Lutomirski <luto@amacapital.net>
Date: Tue, 24 Jun 2014 12:34:36 -0700
Cc: Kees Cook <keescook@chromium.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Alexei Starovoitov <ast@plumgrid.com>, "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>, Andrew Morton <akpm@linux-foundation.org>, Daniel Borkmann <dborkman@redhat.com>, Will Drewry <wad@chromium.org>, Julien Tinnes <jln@chromium.org>, David Drysdale <drysdale@google.com>, Linux API <linux-api@vger.kernel.org>, X86 ML <x86@kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, linux-mips@linux-mips.org, linux-arch <linux-arch@vger.kernel.org>, LSM List <linux-security-module@vger.kernel.org>
In-reply-to: <20140624193055.GA4482@redhat.com>
List-archive: <http://www.linux-mips.org/archives/linux-mips/>
List-help: <mailto:ecartis@linux-mips.org?Subject=help>
List-id: linux-mips <linux-mips.eddie.linux-mips.org>
List-owner: <mailto:ralf@linux-mips.org>
List-post: <mailto:linux-mips@linux-mips.org>
List-software: Ecartis version 1.0.0
List-subscribe: <mailto:ecartis@linux-mips.org?subject=subscribe%20linux-mips>
List-unsubscribe: <mailto:ecartis@linux-mips.org?subject=unsubscribe%20linux-mips>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <1403560693-21809-1-git-send-email-keescook@chromium.org> <1403560693-21809-5-git-send-email-keescook@chromium.org> <20140624191815.GA3623@redhat.com> <CALCETrVgpP=zOtiQafVgcic2T95TdEM5DTvHYXWTbcZ14xBqHQ@mail.gmail.com> <20140624193055.GA4482@redhat.com>
Sender: linux-mips-bounce@linux-mips.org
On Tue, Jun 24, 2014 at 12:30 PM, Oleg Nesterov <oleg@redhat.com> wrote:
> On 06/24, Andy Lutomirski wrote:
>>
>> On Tue, Jun 24, 2014 at 12:18 PM, Oleg Nesterov <oleg@redhat.com> wrote:
>> >>
>> >> -struct seccomp { };
>> >> +struct seccomp {
>> >> +     unsigned long flags;
>> >> +};
>> >
>> > A bit messy ;)
>> >
>> > I am wondering if we can simply do
>> >
>> >         static inline bool current_no_new_privs(void)
>> >         {
>> >                 if (current->no_new_privs)
>> >                         return true;
>> >
>> >         #ifdef CONFIG_SECCOMP
>> >                 if (test_thread_flag(TIF_SECCOMP))
>> >                         return true;
>> >         #endif
>>
>> Nope -- privileged users can enable seccomp w/o nnp.
>
> Indeed, I am stupid.
>
> Still it would be nice to cleanup this somehow. The new member is only
> used as a previous ->no_new_privs, just it is long to allow the concurent
> set/get. Logically it doesn't even belong to seccomp{}.

We could add an unsigned long atomic flags field to task_struct.

Grr.  Why isn't there an unsigned *int* atomic bitmask type?  Even u64
would be better.  unsigned long is useless.

>
> Oleg.
>



-- 
Andy Lutomirski
AMA Capital Management, LLC

<Prev in Thread] Current Thread [Next in Thread>