From patchwork Thu Aug 27 14:58:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 11740845 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 09424739 for ; Thu, 27 Aug 2020 14:58:58 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 61AB222B4B for ; Thu, 27 Aug 2020 14:58:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XUB4mNqp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 61AB222B4B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-19702-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 12166 invoked by uid 550); 27 Aug 2020 14:58:56 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 12143 invoked from network); 27 Aug 2020 14:58:55 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1598540323; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=hzfczoY08KCAOXrJ4QPUBcOl3kLlAqwyM9dLVlxgAlg=; b=XUB4mNqpQVGX1lJOTw7ArMwptRJKdM8lobpXI/acVB9WOQX4mUptM1HhIKECvN5IoS89nq DstFmxawp/RVa/5fEgiICJWEsvkK2pRX+xRBQNF/gRoZ0T0Aj0h6rze2JZlFLVGIdCkZyN 8nXnCITRriEBwucli6TqjO6JeO3NQEE= X-MC-Unique: OgZhy-oMOZaq0ggeHWE2Pg-1 From: Stefano Garzarella To: Jens Axboe Cc: Kernel Hardening , Christian Brauner , linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, Alexander Viro , Stefan Hajnoczi , Jann Horn , Jeff Moyer , Aleksa Sarai , Sargun Dhillon , linux-kernel@vger.kernel.org, Kees Cook Subject: [PATCH v6 0/3] io_uring: add restrictions to support untrusted applications and guests Date: Thu, 27 Aug 2020 16:58:28 +0200 Message-Id: <20200827145831.95189-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 v6: - moved restriction checks in a function [Jens] - changed ret value handling in io_register_restrictions() [Jens] v5: https://lore.kernel.org/io-uring/20200827134044.82821-1-sgarzare@redhat.com/ v4: https://lore.kernel.org/io-uring/20200813153254.93731-1-sgarzare@redhat.com/ v3: https://lore.kernel.org/io-uring/20200728160101.48554-1-sgarzare@redhat.com/ 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 | 172 ++++++++++++++++++++++++++++++++-- include/uapi/linux/io_uring.h | 60 +++++++++--- 2 files changed, 215 insertions(+), 17 deletions(-)