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 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 57FFEC38142 for ; Fri, 27 Jan 2023 23:03:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674860599; h=from:from:sender:sender: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: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=FmzriAvj04dIO/cEhDW5ipO1p3LepzDDt/u89U4epA0=; b=LRr46TpcYhFxvM68hLbfzuEKRql/DWK+UxgkNR0m6BxAolXarwZsX9K1VVjwfUi+bawzqZ 5Z/YIYyFApn6P9CX9ZOmq/iczWAw1yq2G9rq5XKG/5l5t3a6th6Rm+G4orhOV5TErk4V8u rBMcvMRT8+euiN26yWgNGmlLa82s9po= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-624-8kZ4ELBTO1u8ZPOicBL9wA-1; Fri, 27 Jan 2023 18:03:16 -0500 X-MC-Unique: 8kZ4ELBTO1u8ZPOicBL9wA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4A8BD3C021A3; Fri, 27 Jan 2023 23:03:14 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (unknown [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2AE1240C945A; Fri, 27 Jan 2023 23:03:14 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id ECF7B194658D; Fri, 27 Jan 2023 23:03:13 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id BD63C194658D for ; Fri, 27 Jan 2023 23:02:48 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id F212E1121318; Fri, 27 Jan 2023 23:02:47 +0000 (UTC) Received: from madcap2.tricolour.ca (ovpn-0-3.rdu2.redhat.com [10.22.0.3]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 70FA21121314; Fri, 27 Jan 2023 23:02:46 +0000 (UTC) Date: Fri, 27 Jan 2023 18:02:44 -0500 From: Richard Guy Briggs To: Jens Axboe Subject: Re: [PATCH v1 1/2] io_uring,audit: audit IORING_OP_FADVISE but not IORING_OP_MADVISE Message-ID: References: <68eb0c2dd50bca1af91203669f7f1f8312331f38.1674682056.git.rgb@redhat.com> <6d3f76ae-9f86-a96e-d540-cfd45475e288@kernel.dk> MIME-Version: 1.0 In-Reply-To: <6d3f76ae-9f86-a96e-d540-cfd45475e288@kernel.dk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 X-BeenThere: linux-audit@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Audit Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Christian Brauner , LKML , Pavel Begunkov , Linux-Audit Mailing List , Stefan Roesch , Eric Paris , io-uring@vger.kernel.org Errors-To: linux-audit-bounces@redhat.com Sender: "Linux-audit" X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On 2023-01-27 15:45, Jens Axboe wrote: > On 1/27/23 3:35?PM, Paul Moore wrote: > > On Fri, Jan 27, 2023 at 12:24 PM Richard Guy Briggs wrote: > >> > >> Since FADVISE can truncate files and MADVISE operates on memory, reverse > >> the audit_skip tags. > >> > >> Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring") > >> Signed-off-by: Richard Guy Briggs > >> --- > >> io_uring/opdef.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/io_uring/opdef.c b/io_uring/opdef.c > >> index 3aa0d65c50e3..a2bf53b4a38a 100644 > >> --- a/io_uring/opdef.c > >> +++ b/io_uring/opdef.c > >> @@ -306,12 +306,12 @@ const struct io_op_def io_op_defs[] = { > >> }, > >> [IORING_OP_FADVISE] = { > >> .needs_file = 1, > >> - .audit_skip = 1, > >> .name = "FADVISE", > >> .prep = io_fadvise_prep, > >> .issue = io_fadvise, > >> }, > > > > I've never used posix_fadvise() or the associated fadvise64*() > > syscalls, but from quickly reading the manpages and the > > generic_fadvise() function in the kernel I'm missing where the fadvise > > family of functions could be used to truncate a file, can you show me > > where this happens? The closest I can see is the manipulation of the > > page cache, but that shouldn't actually modify the file ... right? > > Yeah, honestly not sure where that came from. Maybe it's being mixed up > with fallocate? All fadvise (or madvise, for that matter) does is > provide hints on the caching or access pattern. On second thought, both > of these should be able to set audit_skip as far as I can tell. That was one suspicion I had. If this is the case, I'd agree both could be skipped. > Jens Axboe - RGB -- Richard Guy Briggs Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635 -- Linux-audit mailing list Linux-audit@redhat.com https://listman.redhat.com/mailman/listinfo/linux-audit