Re: [PATCH v3 0/3] io_uring: add restrictions to support untrusted applications and guests

From: Stefano Garzarella <sgarzare@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: io-uring@vger.kernel.org,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Kees Cook <keescook@chromium.org>, Jeff Moyer <jmoyer@redhat.com>,
	Kernel Hardening <kernel-hardening@lists.openwall.com>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Aleksa Sarai <asarai@suse.de>, Sargun Dhillon <sargun@sargun.me>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Christian Brauner <christian.brauner@ubuntu.com>,
	Jann Horn <jannh@google.com>
Subject: Re: [PATCH v3 0/3] io_uring: add restrictions to support untrusted applications and guests
Date: Thu, 6 Aug 2020 09:49:29 +0200	[thread overview]
Message-ID: <20200806074929.bl6utxrmmx3hf2y2@steredhat> (raw)
In-Reply-To: <20200728160101.48554-1-sgarzare@redhat.com>

Gentle ping.

I'll rebase on master, but if there are any things that I can improve,
I'll be happy to do.

Thanks,
Stefano

On Tue, Jul 28, 2020 at 06:00:58PM +0200, Stefano Garzarella wrote:
> v3:
>  - added IORING_RESTRICTION_SQE_FLAGS_ALLOWED and
>    IORING_RESTRICTION_SQE_FLAGS_REQUIRED
>  - removed IORING_RESTRICTION_FIXED_FILES_ONLY opcode
>  - enabled restrictions only when the rings start
> 
> RFC v2: https://lore.kernel.org/io-uring/20200716124833.93667-1-sgarzare@redhat.com
> 
> RFC v1: https://lore.kernel.org/io-uring/20200710141945.129329-1-sgarzare@redhat.com
> 
> Following the proposal that I send about restrictions [1], I wrote this series
> to add restrictions in io_uring.
> 
> I also wrote helpers in liburing and a test case (test/register-restrictions.c)
> available in this repository:
> https://github.com/stefano-garzarella/liburing (branch: io_uring_restrictions)
> 
> Just to recap the proposal, the idea is to add some restrictions to the
> operations (sqe opcode and flags, register opcode) to safely allow untrusted
> applications or guests to use io_uring queues.
> 
> The first patch changes io_uring_register(2) opcodes into an enumeration to
> keep track of the last opcode available.
> 
> The second patch adds IOURING_REGISTER_RESTRICTIONS opcode and the code to
> handle restrictions.
> 
> The third patch adds IORING_SETUP_R_DISABLED flag to start the rings disabled,
> allowing the user to register restrictions, buffers, files, before to start
> processing SQEs.
> 
> Comments and suggestions are very welcome.
> 
> Thank you in advance,
> Stefano
> 
> [1] https://lore.kernel.org/io-uring/20200609142406.upuwpfmgqjeji4lc@steredhat/
> 
> Stefano Garzarella (3):
>   io_uring: use an enumeration for io_uring_register(2) opcodes
>   io_uring: add IOURING_REGISTER_RESTRICTIONS opcode
>   io_uring: allow disabling rings during the creation
> 
>  fs/io_uring.c                 | 167 ++++++++++++++++++++++++++++++++--
>  include/uapi/linux/io_uring.h |  60 +++++++++---
>  2 files changed, 207 insertions(+), 20 deletions(-)
> 
> -- 
> 2.26.2
> 