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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9BB98C4321E for ; Thu, 5 May 2022 03:15:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240668AbiEEDSh (ORCPT ); Wed, 4 May 2022 23:18:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240703AbiEEDSf (ORCPT ); Wed, 4 May 2022 23:18:35 -0400 Received: from mail-wr1-x432.google.com (mail-wr1-x432.google.com [IPv6:2a00:1450:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E9634EDFB for ; Wed, 4 May 2022 20:14:55 -0700 (PDT) Received: by mail-wr1-x432.google.com with SMTP id q23so4345018wra.1 for ; Wed, 04 May 2022 20:14:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paul-moore-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6ucVUJA/3XuUnAZZDdzrSa00V5OM/xNG80G7w+rY/AM=; b=TuxTKLvOuI4WPEKhesTppN+S/ZTkV+RZI5Wf5W2p+hsrw7/gyfISF8EIiT+rnx8Zu6 zyyiN1wYwPcxjcCA2Sf5xnxirRkddqYIXy2R06dd7qAEUind0ZWDkOOMEqGzEQWPzWzC ZTGq5qihhGmXwhHHxuYfhzg3wQjnC+ThZO+LDVhD9+QIb89VKx3wO1YbUFwWrxXrBCMa SL8UA4+69pMFcpj8M2pJPoNe1J5xXeNZwxQABf1kR5+ALPhLTrYwt5fLtjpY8BeYkBF4 nHH6g/sC5IM5M9d/Ecm/JssJwuDneWf8+Vn5nXmTehGUz+AEuc9+Pt2ztZNda+z83bgG KQkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6ucVUJA/3XuUnAZZDdzrSa00V5OM/xNG80G7w+rY/AM=; b=4BCsFN5s3kOsts+3aSY5k0KV/PghdrF6gkE7H7hW+CgWfVvnAqPuvnkzkeA1avbanN Sw+W+R7FDe13sl3iz20Bv2aSGvruRxGsFaX8hRFJBFBsGdX4rXQCH4vSzNyDp5dGk/KS DzMR28o/+tay+eKyCcXCxg2+D/ISVXeXS+f9eiDofZ3RDArIVAlP+K3urfRUsDMMngiM ZcETj+0gPvLuGOJ3ji/NxrJdXbuD3XiTs2jZSBVfZ4qrx3IqK2T9z90y0umSkzbCS24I M4g8Gt7EL/7NRiaMFrwxBkBV9cjg9xzPS//advkYy7KVSmku2BUUswMLuxebST0dIYtg hkrA== X-Gm-Message-State: AOAM533r+QC3jjMZ4VSMfd9YHI2J0yIg7jQ+K2pghd4IfRxt12yynWEn 8CcR74MigLvkfyQxMKwywXIfQghEtSwFvlJfNGfz X-Google-Smtp-Source: ABdhPJzVMX+BMHIo/6Rx3rt/EGt5DUCiA1Xs3vZE5oz5hLJkbM0bMmp2okAEnKI/au/mDAitpvRIKuXqsxBU1V8TuLw= X-Received: by 2002:a5d:590d:0:b0:20a:c3eb:2584 with SMTP id v13-20020a5d590d000000b0020ac3eb2584mr18412244wrd.18.1651720493308; Wed, 04 May 2022 20:14:53 -0700 (PDT) MIME-Version: 1.0 References: <20220504014440.3697851-1-keescook@chromium.org> <20220504014440.3697851-29-keescook@chromium.org> <20220504234324.GA12556@embeddedor> In-Reply-To: <20220504234324.GA12556@embeddedor> From: Paul Moore Date: Wed, 4 May 2022 23:14:42 -0400 Message-ID: Subject: Re: [PATCH 28/32] selinux: Use mem_to_flex_dup() with xfrm and sidtab To: "Gustavo A. R. Silva" Cc: Kees Cook , Steffen Klassert , Herbert Xu , "David S. Miller" , Stephen Smalley , Eric Paris , Nick Desaulniers , Xiu Jianfeng , =?UTF-8?Q?Christian_G=C3=B6ttsche?= , netdev@vger.kernel.org, selinux@vger.kernel.org, Alexei Starovoitov , alsa-devel@alsa-project.org, Al Viro , Andrew Gabbasov , Andrew Morton , Andy Gross , Andy Lavr , Arend van Spriel , Baowen Zheng , Bjorn Andersson , Boris Ostrovsky , Bradley Grove , brcm80211-dev-list.pdl@broadcom.com, Christian Brauner , Christian Lamparter , Chris Zankel , Cong Wang , Daniel Axtens , Daniel Vetter , Dan Williams , David Gow , David Howells , Dennis Dalessandro , devicetree@vger.kernel.org, Dexuan Cui , Dmitry Kasatkin , Eli Cohen , Eric Dumazet , Eugeniu Rosca , Felipe Balbi , Francis Laniel , Frank Rowand , Franky Lin , Greg Kroah-Hartman , Gregory Greenman , Guenter Roeck , Haiyang Zhang , Hante Meuleman , Hulk Robot , Jakub Kicinski , "James E.J. Bottomley" , James Morris , Jarkko Sakkinen , Jaroslav Kysela , Jason Gunthorpe , Jens Axboe , Johan Hedberg , Johannes Berg , Johannes Berg , John Keeping , Juergen Gross , Kalle Valo , Keith Packard , keyrings@vger.kernel.org, kunit-dev@googlegroups.com, Kuniyuki Iwashima , "K. Y. Srinivasan" , Lars-Peter Clausen , Lee Jones , Leon Romanovsky , Liam Girdwood , linux1394-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-bluetooth@vger.kernel.org, linux-hardening@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-integrity@vger.kernel.org, linux-rdma@vger.kernel.org, linux-scsi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-usb@vger.kernel.org, linux-wireless@vger.kernel.org, linux-xtensa@linux-xtensa.org, llvm@lists.linux.dev, Loic Poulain , Louis Peens , Luca Coelho , Luiz Augusto von Dentz , Marc Dionne , Marcel Holtmann , Mark Brown , "Martin K. Petersen" , Max Filippov , Mimi Zohar , Muchun Song , Nathan Chancellor , =?UTF-8?B?TnVubyBTw6E=?= , Paolo Abeni , Rich Felker , Rob Herring , Russell King , "Serge E. Hallyn" , SHA-cyfmac-dev-list@infineon.com, Simon Horman , Stefano Stabellini , Stefan Richter , Stephen Hemminger , Tadeusz Struk , Takashi Iwai , Tom Rix , Udipto Goswami , Vincenzo Frascino , wcn36xx@lists.infradead.org, Wei Liu , xen-devel@lists.xenproject.org, Yang Yingliang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On Wed, May 4, 2022 at 7:34 PM Gustavo A. R. Silva wrote: > > Hi Paul, > > On Wed, May 04, 2022 at 06:57:28PM -0400, Paul Moore wrote: > > On Tue, May 3, 2022 at 9:57 PM Kees Cook wrote: > > [..] > > > > +++ b/include/uapi/linux/xfrm.h > > > @@ -31,9 +31,9 @@ struct xfrm_id { > > > struct xfrm_sec_ctx { > > > __u8 ctx_doi; > > > __u8 ctx_alg; > > > - __u16 ctx_len; > > > + __DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(__u16, ctx_len); > > > __u32 ctx_sid; > > > - char ctx_str[0]; > > > + __DECLARE_FLEX_ARRAY_ELEMENTS(char, ctx_str); > > > }; > > > > While I like the idea of this in principle, I'd like to hear about the > > testing you've done on these patches. A previous flex array > > conversion in the audit uapi headers ended up causing a problem with > > I'm curious about which commit caused those problems...? Commit ed98ea2128b6 ("audit: replace zero-length array with flexible-array member"), however, as I said earlier, the problem was actually with SWIG, it just happened to be triggered by the kernel commit. There was a brief fedora-devel mail thread about the problem, see the link below: * https://www.spinics.net/lists/fedora-devel/msg297991.html To reiterate, I'm supportive of changes like this, but I would like to hear how it was tested to ensure there are no unexpected problems with userspace. If there are userspace problems it doesn't mean we can't make changes like this, it just means we need to ensure that the userspace issues are resolved first. -- paul-moore.com