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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 43A9CC433E3 for ; Thu, 23 Jul 2020 15:30:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F5F0206E3 for ; Thu, 23 Jul 2020 15:30:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="eXAJZ9XD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729471AbgGWPab (ORCPT ); Thu, 23 Jul 2020 11:30:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726761AbgGWPaa (ORCPT ); Thu, 23 Jul 2020 11:30:30 -0400 Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE4A1C0619DC; Thu, 23 Jul 2020 08:30:29 -0700 (PDT) Received: by mail-qk1-x741.google.com with SMTP id e13so5706830qkg.5; Thu, 23 Jul 2020 08:30:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=4M2X8c1o1GLGue/gT+Yu3vbhPjzYcFb5GdcwmFKqkWY=; b=eXAJZ9XD5BqetmyLyB5TZz7wGQpBNIlz+C1NMxXQWh3hmhzYlYzU8aFhAnM4isDJjo IAqxstbtahBVLsriVMNzBUD7iApZ4zg8mmltzroHrgfdqolM4v07afdVDVmFsEPInZBO hSXLz1yYAtQzKThbpWYZYThayUziLpWJspR7y5zXrWUtM7S8LLIQEjnoEieJysRISUlr vMvsrWA+lB5suoZO39AYNiwSNRSAChRNLhlCTZGyafU0OIXE7wSd9roD0BE6+q3cK6zS gmLoDWoD/yPIlLU7cTuv6WiohyB51M+vXE4OyCqsqs0FWIuLnFfDymgooPM/PcmD17XJ H50A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=4M2X8c1o1GLGue/gT+Yu3vbhPjzYcFb5GdcwmFKqkWY=; b=jtaJ+MfOaubfO5g9m5pWGu4070/Quj3eyx/aAu/Ou4E3OWVZ/QRI6Xv5lpDlYHxX9D 8hRIbFcWrrVn/hYAqMt5mQBs1S4w9cxZmWcoLwJZDLmO5ANJE+xFKW2TTIcJjsZ89n/u nl7QrLpBRy2T9NugpOBnz+U7AR7kJoU+4tNSJ9HdPu4nXOS11/+2aQH/x2BYYDgzAqLS lzFrPN6wOyewzyqpMfcRmgG757Cc4LoP1yTXaOXRvGnfWH7H5/kwIHYpDvCZxEC2Yn1T qnvR/NLumhzGmrQZWLicL9yxKj/s3fpT4e7n68jJUIqe1Imeygg37ICW9FJQs8TnoNfd /QFw== X-Gm-Message-State: AOAM533QryD80IueF8YQbiJgDh5KDo4SLf8mfieVaMhs2DNC03NoWAdP OQZqldvYOvWnDKPtsI8wLCyi0RJD X-Google-Smtp-Source: ABdhPJwR9Hh6hYOYz3Hz+plQtfbh1jjySQlltnsfxlkdKygETBvNDCJ0V/hIO3Ge7DxIOv10r7B7Sg== X-Received: by 2002:a37:5b46:: with SMTP id p67mr5813992qkb.346.1595518228834; Thu, 23 Jul 2020 08:30:28 -0700 (PDT) Received: from localhost.localdomain ([138.204.24.96]) by smtp.gmail.com with ESMTPSA id n81sm2909642qke.11.2020.07.23.08.30.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jul 2020 08:30:27 -0700 (PDT) Received: by localhost.localdomain (Postfix, from userid 1000) id 334DFC18B3; Thu, 23 Jul 2020 12:30:25 -0300 (-03) Date: Thu, 23 Jul 2020 12:30:25 -0300 From: Marcelo Ricardo Leitner To: Christoph Hellwig Cc: netdev@vger.kernel.org, Neil Horman , linux-sctp@vger.kernel.org Subject: Re: [PATCH net-next] sctp: fix slab-out-of-bounds in SCTP_DELAYED_SACK processing Message-ID: <20200723153025.GF3307@localhost.localdomain> References: <5955bc857c93d4bb64731ef7a9e90cb0094a8989.1595450200.git.marcelo.leitner@gmail.com> <20200722204231.GA3398@localhost.localdomain> <20200723092238.GA21143@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200723092238.GA21143@lst.de> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Jul 23, 2020 at 11:22:38AM +0200, Christoph Hellwig wrote: > On Wed, Jul 22, 2020 at 05:42:31PM -0300, Marcelo Ricardo Leitner wrote: > > Cc'ing linux-sctp@vger.kernel.org. > > What do you think of this version, which I think is a little cleaner? It splits up the argument parsing from the actual handling, ok. Looks good. Just one point: > +static int sctp_setsockopt_delayed_ack(struct sock *sk, > + struct sctp_sack_info *params, > + unsigned int optlen) > +{ > + if (optlen == sizeof(struct sctp_assoc_value)) { > + struct sctp_sack_info p; > + > + pr_warn_ratelimited(DEPRECATED > + "%s (pid %d) " > + "Use of struct sctp_assoc_value in delayed_ack socket option.\n" > + "Use struct sctp_sack_info instead\n", > + current->comm, task_pid_nr(current)); > + > + memcpy(&p, params, sizeof(struct sctp_assoc_value)); > + p.sack_freq = p.sack_delay ? 0 : 1; Please add a comment saying that sctp_sack_info.sack_delay maps exactly to sctp_assoc_value.assoc_value, so that's why we can do memcpy and read assoc_value as sack_delay. I think it will help us not trip on this again in the future. > + return __sctp_setsockopt_delayed_ack(sk, &p); > + } > + > + if (optlen != sizeof(struct sctp_sack_info)) > + return -EINVAL; > + if (params->sack_delay == 0 && params->sack_freq == 0) > + return 0; > + return __sctp_setsockopt_delayed_ack(sk, params); > +} > + > /* 7.1.3 Initialization Parameters (SCTP_INITMSG) > * > * Applications can specify protocol parameters for the default association