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From:   Kees Cook <keescook@chromium.org>
To:     avagin@gmail.com, linux-kernel@vger.kernel.org,
        0x7f454c46@gmail.com, brauner@kernel.org
Cc:     Kees Cook <keescook@chromium.org>, ebiederm@xmission.com,
        linux-mm@kvack.org, fweimer@redhat.com
Subject: Re: [PATCH 1/2] fs/exec: allow to unshare a time namespace on vfork+exec
Date:   Wed, 15 Jun 2022 08:01:48 -0700
Message-Id: <165530530544.261757.10728167525988459977.b4-ty@chromium.org>
In-Reply-To: <20220613060723.197407-1-avagin@gmail.com>
References: <20220613060723.197407-1-avagin@gmail.com>
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On Sun, 12 Jun 2022 23:07:22 -0700, Andrei Vagin wrote:
> Right now, a new process can't be forked in another time namespace
> if it shares mm with its parent. It is prohibited, because each time
> namespace has its own vvar page that is mapped into a process address
> space.
> 
> When a process calls exec, it gets a new mm and so it could be "legal"
> to switch time namespace in that case. This was not implemented and
> now if we want to do this, we need to add another clone flag to not
> break backward compatibility.
> 
> [...]

Applied to for-next/execve, thanks!

[1/2] fs/exec: allow to unshare a time namespace on vfork+exec
      https://git.kernel.org/kees/c/133e2d3e81de
[2/2] testing/timens: add a test for vfork+exit
      https://git.kernel.org/kees/c/6342140db660

-- 
Kees Cook