From: Andrew Morton <akpm@linux-foundation.org>
To: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: linux-kernel@vger.kernel.org,
Nicolas Geoffray <ngeoffray@google.com>,
kernel-team@android.com, Hugh Dickins <hughd@google.com>,
linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
Shuah Khan <shuah@kernel.org>
Subject: Re: [PATCH 1/2] memfd: Fix COW issue on MAP_PRIVATE and F_SEAL_FUTURE_WRITE mappings
Date: Thu, 7 Nov 2019 17:00:23 -0800 [thread overview]
Message-ID: <20191107170023.0695732bb67eb80acd4caee5@linux-foundation.org> (raw)
In-Reply-To: <20191107195355.80608-1-joel@joelfernandes.org>
On Thu, 7 Nov 2019 14:53:54 -0500 "Joel Fernandes (Google)" <joel@joelfernandes.org> wrote:
> F_SEAL_FUTURE_WRITE has unexpected behavior when used with MAP_PRIVATE:
> A private mapping created after the memfd file that gets sealed with
> F_SEAL_FUTURE_WRITE loses the copy-on-write at fork behavior, meaning
> children and parent share the same memory, even though the mapping is
> private.
That sounds fairly serious. Should this be backported into -stable kernels?
next prev parent reply other threads:[~2019-11-08 1:00 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-07 19:53 [PATCH 1/2] memfd: Fix COW issue on MAP_PRIVATE and F_SEAL_FUTURE_WRITE mappings Joel Fernandes (Google)
2019-11-07 19:53 ` [PATCH 2/2] memfd: Add test for COW " Joel Fernandes (Google)
2019-11-08 1:00 ` Andrew Morton [this message]
2019-11-08 2:06 ` [PATCH 1/2] memfd: Fix COW issue " Joel Fernandes
2019-11-08 3:25 ` Andrew Morton
2019-11-08 6:37 ` Greg KH
2019-11-08 15:34 ` Joel Fernandes
2019-11-08 6:33 ` Christoph Hellwig
2019-11-08 15:35 ` Joel Fernandes
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