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=-4.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=ham 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 279ABC04AAC for ; Mon, 20 May 2019 18:57:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0722A205ED for ; Mon, 20 May 2019 18:57:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=isovalent-com.20150623.gappssmtp.com header.i=@isovalent-com.20150623.gappssmtp.com header.b="fMyll/PY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726282AbfETS5v (ORCPT ); Mon, 20 May 2019 14:57:51 -0400 Received: from mail-lj1-f195.google.com ([209.85.208.195]:38039 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726125AbfETS5v (ORCPT ); Mon, 20 May 2019 14:57:51 -0400 Received: by mail-lj1-f195.google.com with SMTP id 14so13500557ljj.5 for ; Mon, 20 May 2019 11:57:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isovalent-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=OmaVPUNIZXzoguiohx42nQv5edtRi7vwn1kzPXHaCDU=; b=fMyll/PYRqDhUKiFB8FWnKnTIEQzIkiza71tvGxxVJhYoLtma2pufkLzZrNJzfHMCQ DEQUyJfZ/FKF9qXw4Gszyc7Cx/Wchwc6YJmaz6m/TMqJHRmLqjSWQnFpmV3uyA7JmLbe merYv5HX8zgk+6qeaa+yLv93n/+XXh57JMhmTAsXu/qsGMm4RTYfTixRoIzrDzByGpEV t498nAncnts0ff/6jHnDXDkJy+A4K6WC7xkUSaeb3OLLNwzfPKZPtPCFmrURE1bnpspH h0Mna6z+leiSlSL+sberZ70d7qdflrvzfoSwWOx88e+dDllUB5N64Y+xGHQt4tv6UOVs yt8Q== 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=OmaVPUNIZXzoguiohx42nQv5edtRi7vwn1kzPXHaCDU=; b=T+FBEXlQVxOagJxbuwVxbiS7UMcR1HdsKT0E/TqyGXbH99J24gzOboOg2qnWLjcGeY wFA3mOXrdqN+x42cjVZyezbHRoM34EHGeFUPLeh0q0EgIDqAaQive61TCiWRba8ul0dg bUQYTMhBgCZGkiQKNMCYnUCAl+ozNDfg36wYOj9RYVzr7wYfbqjJvVpnqC6kLSjSZf4E ibhE4hishfrmeZ3jq6lNaGc3jiB5XbNfPHU7G9rddz3Qma53Sz+EWUzrm10spRM+wLIz NCAVXdasQ/Ns80/weSsnb3kt22jkSFlx3agO8Ox8NCgkKRnoGfF+EGMfvVasbKOnhmRJ 2QCw== X-Gm-Message-State: APjAAAUHw5YS7TJ+PI63uMOUAG/NwvJP8nCl/Dr63I+tzuKgT35TBcQH tjFAUn81iP0DTVufuwZdzIm3XQTBWynFkubxGx3HMQ== X-Google-Smtp-Source: APXvYqy6M9AYAHvKJNCbUtN+nVQJi5irsspzQdgBoUYpuK5uXs+rCoPdY/21xnEcQ0CBbK70aIgXROavyXsEF4+arOE= X-Received: by 2002:a2e:9d4e:: with SMTP id y14mr12542742ljj.199.1558378669341; Mon, 20 May 2019 11:57:49 -0700 (PDT) MIME-Version: 1.0 References: <20190517212117.2792415-1-kafai@fb.com> In-Reply-To: <20190517212117.2792415-1-kafai@fb.com> From: Joe Stringer Date: Mon, 20 May 2019 11:57:37 -0700 Message-ID: Subject: Re: [PATCH bpf] bpf: Check sk_fullsock() before returning from bpf_sk_lookup() To: Martin KaFai Lau Cc: bpf@vger.kernel.org, Networking , Alexei Starovoitov , Daniel Borkmann , Kernel Team Content-Type: text/plain; charset="UTF-8" Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, May 17, 2019 at 2:21 PM Martin KaFai Lau wrote: > > The BPF_FUNC_sk_lookup_xxx helpers return RET_PTR_TO_SOCKET_OR_NULL. > Meaning a fullsock ptr and its fullsock's fields in bpf_sock can be > accessed, e.g. type, protocol, mark and priority. > Some new helper, like bpf_sk_storage_get(), also expects > ARG_PTR_TO_SOCKET is a fullsock. > > bpf_sk_lookup() currently calls sk_to_full_sk() before returning. > However, the ptr returned from sk_to_full_sk() is not guaranteed > to be a fullsock. For example, it cannot get a fullsock if sk > is in TCP_TIME_WAIT. > > This patch checks for sk_fullsock() before returning. If it is not > a fullsock, sock_gen_put() is called if needed and then returns NULL. > > Fixes: 6acc9b432e67 ("bpf: Add helper to retrieve socket in BPF") > Cc: Joe Stringer > Signed-off-by: Martin KaFai Lau > --- Acked-by: Joe Stringer