From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE97AC04FF3 for ; Sat, 22 May 2021 02:36:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AE3561164 for ; Sat, 22 May 2021 02:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231159AbhEVCiT (ORCPT ); Fri, 21 May 2021 22:38:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230488AbhEVCiS (ORCPT ); Fri, 21 May 2021 22:38:18 -0400 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82E31C061574 for ; Fri, 21 May 2021 19:36:53 -0700 (PDT) Received: by mail-ed1-x52d.google.com with SMTP id h16so25359688edr.6 for ; Fri, 21 May 2021 19:36:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paul-moore-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=/bYvAACSgc8/uW7uI1cczUf6zncLtiw3niodFFHXbfQ=; b=zueRaqvi0ABnvezPF7a/BvC89XCqv9MA5lpZVc06qJfZkfTl6XHxnBOB/b37aSowba MvmSbZcggtkx+qjxr+EQ8Vt4UbkoAt9GxSaZcQWxj+cXScSaCGqbmirFZ3ycLfQgLS/9 WMEhgZTGZ+Jyxu49B0c2KfgCbz4b0bJfFQtZl+2Vauh5sD/CpwxFmg9xTbxyFIE5c6Qq a5Oo9V20+jqFrSCcPiFpYwKUeTyINRxOIsc57wXIsZFUmGXsNtcROoIzG3rhmdETAJj3 XfuB/9Adbbapv5EF6kx5uRfFhVUGUWtZ6qINh5fUAFO5uZJXq2fxmJfHd2s/zAercPZD AZpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=/bYvAACSgc8/uW7uI1cczUf6zncLtiw3niodFFHXbfQ=; b=AO+5viGUi+CE3eSKa6PpV21LaisCHwORPS77hSk1WCWlqHlj36ZBtBl9PO458FAwqz sWofqLahiE0pBKODuAALm1Bq0jpoSBn8zUtVTzF2pyDG8WBVGezLCnl6Bq95DZeWG8XZ fBswd/wkb2JMidQqpw9/kPK8JlhgxJb/RVdIbGbkMiWFZDbzzq/uv3fdRivg4g48gtek DnOMWtJKOS9z27EGiIq4+dAedVYuRvqpncpq+H622NhwCdi6mxmmaMY+unAGoQWPLOWU fcPSoZMcL/M32KWjGAU8ujf91LxKpHDCha+31CNEyuScsl0BgRKbroH/ajEz/I1GJDHR U11g== X-Gm-Message-State: AOAM532HiQ5xUjj8KUg47hxWlnyWysTTcvvucLNepqJjmAKysIFO0eC1 0lyP6YmmO4AQt+afalEorMjQM+H35SuLnO/8fA2d X-Google-Smtp-Source: ABdhPJz9UvC/faFDkiRLsiBXVJ9IkfixZn9C7UN/IQ22MxEe2N1Eq1BZgP//f1I2SXPZB1KVfu8b/AJWi+UrvHYAZ34= X-Received: by 2002:aa7:c349:: with SMTP id j9mr13964677edr.135.1621651012073; Fri, 21 May 2021 19:36:52 -0700 (PDT) MIME-Version: 1.0 References: <162163367115.8379.8459012634106035341.stgit@sifl> <162163379461.8379.9691291608621179559.stgit@sifl> In-Reply-To: From: Paul Moore Date: Fri, 21 May 2021 22:36:40 -0400 Message-ID: Subject: Re: [RFC PATCH 2/9] audit,io_uring,io-wq: add some basic audit support to io_uring To: Pavel Begunkov Cc: linux-security-module@vger.kernel.org, selinux@vger.kernel.org, linux-audit@redhat.com, io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org, Kumar Kartikeya Dwivedi , Jens Axboe , Alexander Viro Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Fri, May 21, 2021 at 8:22 PM Pavel Begunkov wrote: > On 5/21/21 10:49 PM, Paul Moore wrote: > > WARNING - This is a work in progress and should not be merged > > anywhere important. It is almost surely not complete, and while it > > probably compiles it likely hasn't been booted and will do terrible > > things. You have been warned. > > > > This patch adds basic auditing to io_uring operations, regardless of > > their context. This is accomplished by allocating audit_context > > structures for the io-wq worker and io_uring SQPOLL kernel threads > > as well as explicitly auditing the io_uring operations in > > io_issue_sqe(). The io_uring operations are audited using a new > > AUDIT_URINGOP record, an example is shown below: > > > > % > > > > Thanks to Richard Guy Briggs for review and feedback. > > > > Signed-off-by: Paul Moore > > --- > [...] > > diff --git a/fs/io_uring.c b/fs/io_uring.c > > index e481ac8a757a..e9941d1ad8fd 100644 > > --- a/fs/io_uring.c > > +++ b/fs/io_uring.c > > @@ -78,6 +78,7 @@ > > #include > > #include > > #include > > +#include > > > > #define CREATE_TRACE_POINTS > > #include > > @@ -6105,6 +6106,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) > > if (req->work.creds && req->work.creds != current_cred()) > > creds = override_creds(req->work.creds); > > > > + if (req->opcode < IORING_OP_LAST) > > always true at this point I placed the opcode check before the audit call because the switch statement below which handles the operation dispatching has a 'ret = -EINVAL' for the default case, implying that there are some paths where an invalid opcode could be passed into the function. Obviously if that is not the case and you can guarantee that req->opcode will always be valid we can easily drop the check prior to the audit call. > > + audit_uring_entry(req->opcode); > > So, it adds two if's with memory loads (i.e. current->audit_context) > per request in one of the hottest functions here... No way, nack > > Maybe, if it's dynamically compiled into like kprobes if it's > _really_ used. I'm open to suggestions on how to tweak the io_uring/audit integration, if you don't like what I've proposed in this patchset, lets try to come up with a solution that is more palatable. If you were going to add audit support for these io_uring operations, how would you propose we do it? Not being able to properly audit io_uring operations is going to be a significant issue for a chunk of users, if it isn't already, we need to work to find a solution to this problem. Unfortunately I don't think dynamically inserting audit calls is something that would meet the needs of the audit community (I fear it would run afoul of the various security certifications), and it definitely isn't something that we support at present. -- paul moore www.paul-moore.com