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Date:   Thu, 29 Jun 2023 13:27:10 +0000
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Message-ID: <20230629132711.1712536-1-matteorizzo@google.com>
Subject: [PATCH v2 0/1] Add a sysctl to disable io_uring system-wide
From:   Matteo Rizzo <matteorizzo@google.com>
To:     linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        io-uring@vger.kernel.org
Cc:     matteorizzo@google.com, jordyzomer@google.com, evn@google.com,
        poprdi@google.com, corbet@lwn.net, axboe@kernel.dk,
        asml.silence@gmail.com, akpm@linux-foundation.org,
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Over the last few years we've seen many critical vulnerabilities in
io_uring[1] which could be exploited by an unprivileged process to gain
control over the kernel. This patch introduces a new sysctl which disables
the creation of new io_uring instances system-wide.

The goal of this patch is to give distros, system admins, and cloud
providers a way to reduce the risk of privilege escalation through io_uring
where disabling it with seccomp or at compile time is not practical. For
example a distro or cloud provider might want to disable io_uring by
default and have users enable it again if they need to run a program that
requires it. The new sysctl is designed to let a user with root on the
machine enable and disable io_uring systemwide at runtime without requiring
a kernel recompilation or a reboot.

[1] Link: https://goo.gle/limit-iouring

---
v2:
	* Documentation style fixes
	* Add a third level that only disables io_uring for unprivileged
	  processes


Matteo Rizzo (1):
  Add a new sysctl to disable io_uring system-wide

 Documentation/admin-guide/sysctl/kernel.rst | 19 +++++++++++++
 io_uring/io_uring.c                         | 30 +++++++++++++++++++++
 2 files changed, 49 insertions(+)

-- 
2.41.0.162.gfafddb0af9-goog