From: Kees Cook <keescook@chromium.org>
To: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>,
Tycho Andersen <tycho@tycho.pizza>,
Andy Lutomirski <luto@amacapital.net>,
Will Drewry <wad@chromium.org>,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH resend] seccomp: Make duplicate listener detection non-racy
Date: Mon, 5 Oct 2020 15:30:54 -0700 [thread overview]
Message-ID: <160193704489.2698420.14892403272288554518.b4-ty@chromium.org> (raw)
In-Reply-To: <20201005014401.490175-1-jannh@google.com>
On Mon, 5 Oct 2020 03:44:01 +0200, Jann Horn wrote:
> Currently, init_listener() tries to prevent adding a filter with
> SECCOMP_FILTER_FLAG_NEW_LISTENER if one of the existing filters already
> has a listener. However, this check happens without holding any lock that
> would prevent another thread from concurrently installing a new filter
> (potentially with a listener) on top of the ones we already have.
>
> Theoretically, this is also a data race: The plain load from
> current->seccomp.filter can race with concurrent writes to the same
> location.
>
> [...]
Applied, thanks!
I added the stable CC, but I'd agree: it's not so urgent that I need to
get this into Linus's tree ahead of the regular merge window. :)
[1/1] seccomp: Make duplicate listener detection non-racy
https://git.kernel.org/kees/c/ed2d479d3335
--
Kees Cook
prev parent reply other threads:[~2020-10-05 22:33 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-05 1:44 [PATCH resend] seccomp: Make duplicate listener detection non-racy Jann Horn
2020-10-05 22:30 ` Kees Cook [this message]
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