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Date:   Tue, 27 Jun 2023 10:10:36 -0700
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Subject: Re: [PATCH 1/1] Add a new sysctl to disable io_uring system-wide
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To:     Matteo Rizzo <matteorizzo@google.com>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, io-uring@vger.kernel.org
Cc:     jordyzomer@google.com, evn@google.com, poprdi@google.com,
        corbet@lwn.net, axboe@kernel.dk, asml.silence@gmail.com,
        akpm@linux-foundation.org, keescook@chromium.org,
        rostedt@goodmis.org, dave.hansen@linux.intel.com,
        ribalda@chromium.org, chenhuacai@kernel.org, steve@sk2.org,
        gpiccoli@igalia.com, ldufour@linux.ibm.com
References: <20230627120058.2214509-1-matteorizzo@google.com>
 <20230627120058.2214509-2-matteorizzo@google.com>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <20230627120058.2214509-2-matteorizzo@google.com>
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On 6/27/23 05:00, Matteo Rizzo wrote:
> +Prevents all processes from creating new io_uring instances. Enabling this
> +shrinks the kernel's attack surface.
> +
> += =============================================================
> +0 All processes can create io_uring instances as normal. This is the default
> +  setting.
> +1 io_uring is disabled. io_uring_setup always fails with -EPERM. Existing
> +  io_uring instances can still be used.
> += =============================================================

I'm using fio + io_uring all the time on Android devices. I think we need a
better solution than disabling io_uring system-wide, e.g. a mechanism based
on SELinux that disables io_uring for apps and that keeps io_uring enabled
for processes started via 'adb root && adb shell ...'

Bart.