From patchwork Thu Aug 27 13:40:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 11740709 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 2D5ED722 for ; Thu, 27 Aug 2020 13:41:15 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 399A4207CD for ; Thu, 27 Aug 2020 13:41:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NFiZq1ZF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 399A4207CD 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-19690-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 22193 invoked by uid 550); 27 Aug 2020 13:41:12 -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 22172 invoked from network); 27 Aug 2020 13:41:12 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1598535660; 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=3kTaC7Koe/EnnFofVOMX9+NxqY3+OHKyUa+e0ym9rLY=; b=NFiZq1ZF5AzVXmc8LpBXRbMZqdy/rhnk1L+/ew98zvoc1SrquoF8qhGRz/YREBLBr56xUh vC3U+odwtKmMrjH2SGGC1DPOUt0wTrH8F2yEwBkE/WBgaHYvtmuCwspRKmNW+FUGkOmUwx CAVD0Nh9w5scN8NeaJGF/N9TFuFfnrQ= X-MC-Unique: 1b2BLQODPwSPJVSK4YyNIg-1 From: Stefano Garzarella To: Jens Axboe Cc: Aleksa Sarai , Kernel Hardening , Jann Horn , io-uring@vger.kernel.org, Christian Brauner , linux-fsdevel@vger.kernel.org, Alexander Viro , Stefan Hajnoczi , linux-kernel@vger.kernel.org, Sargun Dhillon , Kees Cook , Jeff Moyer Subject: [PATCH v5 0/3] io_uring: add restrictions to support untrusted applications and guests Date: Thu, 27 Aug 2020 15:40:41 +0200 Message-Id: <20200827134044.82821-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 v5: - explicitly assigned enum values [Kees] - replaced kmalloc/copy_from_user with memdup_user [kernel test robot] - added Kees' R-b tags 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 | 155 ++++++++++++++++++++++++++++++++-- include/uapi/linux/io_uring.h | 60 ++++++++++--- 2 files changed, 198 insertions(+), 17 deletions(-)