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=-11.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 CCDBAC433DF for ; Thu, 21 May 2020 15:21:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A08F820829 for ; Thu, 21 May 2020 15:21:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="C459PlgM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729888AbgEUPVP (ORCPT ); Thu, 21 May 2020 11:21:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728291AbgEUPVP (ORCPT ); Thu, 21 May 2020 11:21:15 -0400 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12954C061A0E for ; Thu, 21 May 2020 08:21:14 -0700 (PDT) Received: by mail-qv1-xf49.google.com with SMTP id t11so7455824qvv.11 for ; Thu, 21 May 2020 08:21:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=9lkpAxU/Frlu8q2+TZv8WXsY+5fekFwCMxqOU2GbUws=; b=C459PlgMpa8qYr/Ahy0+Odf3EG4yZDSUOxlCSEUs+vVxwUqTKOmlVKvJpZ/abcX8fn 7BtLnaWLCt0yWkz5ouOKN/pOmyT2AxSrampHkinUP48QYrjJT4PJ4QSaSuD3p0+yMASt eQKDY+G7Onm5nEfjgOj4YXTkrVikCzhyhE87IpPYsZo3K9DXDNu18MI1VSEAgBNJVowx ZRzjq1oAVSVpo/2S/65Sy0/bdqNPRlD5YXdYouIcqJtB7BeqZp6h6JXToBjAH3Oy951D mSwSHZMLXUTArnfK0RGWZRNCAwNW6o2zePN8a0nyL9gGEfRxr5xuoLgiJuiX2RK4YGQm m9UA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=9lkpAxU/Frlu8q2+TZv8WXsY+5fekFwCMxqOU2GbUws=; b=c+1T8suT+U397yUQksQyZMm5hQPdVvj7I0ukfgQYZz1WQfNL7w+NzrdiVCQhi2EFYP Qi28sqQO7DDmojZNL55dcaZNUgZxn4n+XNKeRDgMMv7ZhpRtEBrYsLsKyIZnenJh4/ES g3H7M0WfGhRpgPAowKmEwrAjCQUVIFcAWsbKEAudX8Sp+HRVF5RFA7b+BM/ET44HdRQ4 ICd1SBt/q4MdG1amT8wbhprGodVnW7+o1BRK2pbFmT+y83Y2S4u09FzTLOGSL9Rw+aWX ckTRBelG8etQHxyeuol0cwZa8c8YT7f63kVjmnyvv5aLwWQ3CxKXl69jI37PW3qXvF9K sGFg== X-Gm-Message-State: AOAM533+mL3LZX3NOxo8HeBZkug6FZ7tYvMOWxzEWGU/z8abkkLjQdAe GX7ag7sNnfsDlLghjDu/HJ/+eHs= X-Google-Smtp-Source: ABdhPJwEeEqc2SIIxOIk9bV5/VcJvZjsEaWLrXJuywDArF1hfveBKPIGJL/MpTKGOkINxIeFM/xgsEY= X-Received: by 2002:a0c:906e:: with SMTP id o101mr10478572qvo.180.1590074473192; Thu, 21 May 2020 08:21:13 -0700 (PDT) Date: Thu, 21 May 2020 08:21:11 -0700 In-Reply-To: <20200521083435.560256-1-jakub@cloudflare.com> Message-Id: <20200521152111.GB49942@google.com> Mime-Version: 1.0 References: <20200521083435.560256-1-jakub@cloudflare.com> Subject: Re: [PATCH bpf v2] flow_dissector: Drop BPF flow dissector prog ref on netns cleanup From: sdf@google.com To: Jakub Sitnicki Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, kernel-team@cloudflare.com, Alexei Starovoitov Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 05/21, Jakub Sitnicki wrote: > When attaching a flow dissector program to a network namespace with > bpf(BPF_PROG_ATTACH, ...) we grab a reference to bpf_prog. > If netns gets destroyed while a flow dissector is still attached, and > there > are no other references to the prog, we leak the reference and the program > remains loaded. > Leak can be reproduced by running flow dissector tests from selftests/bpf: > # bpftool prog list > # ./test_flow_dissector.sh > ... > selftests: test_flow_dissector [PASS] > # bpftool prog list > 4: flow_dissector name _dissect tag e314084d332a5338 gpl > loaded_at 2020-05-20T18:50:53+0200 uid 0 > xlated 552B jited 355B memlock 4096B map_ids 3,4 > btf_id 4 > # > Fix it by detaching the flow dissector program when netns is going away. > Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") > Signed-off-by: Jakub Sitnicki Reviewed-by: Stanislav Fomichev Thank you!