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

Message

Stefano Garzarella July 28, 2020, 4 p.m. UTC

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/[e-mail]

RFC v1: https://lore.kernel.org/io-uring/[e-mail]

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(-)

Comments

Stefano Garzarella Aug. 6, 2020, 7:49 a.m. UTC | #1

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/[e-mail]
> 
> RFC v1: https://lore.kernel.org/io-uring/[e-mail]
> 
> 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
>