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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 2750AC433ED for ; Wed, 12 May 2021 12:35:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E43F8613CA for ; Wed, 12 May 2021 12:35:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232607AbhELMg1 (ORCPT ); Wed, 12 May 2021 08:36:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232602AbhELMg0 (ORCPT ); Wed, 12 May 2021 08:36:26 -0400 Received: from mail-ed1-x533.google.com (mail-ed1-x533.google.com [IPv6:2a00:1450:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7134C061574 for ; Wed, 12 May 2021 05:35:17 -0700 (PDT) Received: by mail-ed1-x533.google.com with SMTP id b17so26874068ede.0 for ; Wed, 12 May 2021 05:35:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=B+qYBeg0LU7qe9FeyoLl+k4V1mooIx6Srj0QdL7z8tc=; b=FjXQxpNwImq2bwYHzsIHZLnrerzRfxMcSSRNqhZcZYWNzdINe0Vud0wr78sKhIMNl8 7RVwgVC3SFE2FTAH3/OKgQ3pYusBtFHs63VR1zSSynQ6Nu3LiYXoaMeX6IX/z68TUtBh xRVK0jid++g22nW+OgpdaAeiC4g/7OVZmYqtAC3KSDV9cyAFhDjgcSPsGY9XJX2/P0GJ 1+JnRi+MohHNZ+UxlZeB4JWmm2EowBV99AYQX6NWjOk11ELtxr5ltAmQ9IMB2R0sHe4d YDFKTVSMDLn/atY6dyKbmxafzU8Xlaz6WeTAjqmEW8An0PzErJC8I1q9wpKaJ/LgOm50 oUkw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=B+qYBeg0LU7qe9FeyoLl+k4V1mooIx6Srj0QdL7z8tc=; b=fVwIJwRLbd2b9IqIfyozkeNsxJV28MC5+Dth3pwSfNj/h2QbFYM7APo2ujLPspcMnY 9aWnAFPJfz7QurtY2AWdJY2EelbVgUblntx85IFH99ujM4cyGlcO2gLE1qHFnhZMpBCx DUMAW2NkF1Lfi4ByjAIpE+JKCGHmUar0ZGst6m3I4ZJgxCZePxiOh1z/JxwCe8bTHnX7 nRCNaWpGG25TggDYup2lJC2sPtf1vGP1kBHGfYC2cNrxzxAdcwp/WtPH8Dq51q3mhLlv e+coxjfkdiU7Cu5EXRTrWOPJZp1LbBU78zpyti7WTqCxKtQegLDjhVE8tDWkrMu8oSow jHrg== X-Gm-Message-State: AOAM533yqWtlTRDP7sgmSqWtIs1tGcVnFO6YmIDMxQNUsDX3bc/h2EOp zceqpxIb3eN332nxKmfluOdJJ7pYe9+ZhySU X-Google-Smtp-Source: ABdhPJwOn721K04BSYLRQMvOMWYGauXUTgOMfrqtnATQJOY4kZOMqeaSneYD7dczYVMqzx327jVNDQ== X-Received: by 2002:aa7:d658:: with SMTP id v24mr42258523edr.290.1620822916561; Wed, 12 May 2021 05:35:16 -0700 (PDT) Received: from eldamar (80-218-24-251.dclient.hispeed.ch. [80.218.24.251]) by smtp.gmail.com with ESMTPSA id v1sm11896366ejw.117.2021.05.12.05.35.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 May 2021 05:35:15 -0700 (PDT) Sender: Salvatore Bonaccorso Date: Wed, 12 May 2021 14:35:14 +0200 From: Salvatore Bonaccorso To: gregkh@linuxfoundation.org Cc: lucien.xin@gmail.com, davem@davemloft.net, orcohen@paloaltonetworks.com, stable@vger.kernel.org Subject: Re: FAILED: patch "[PATCH] sctp: delay auto_asconf init until binding the first addr" failed to apply to 5.12-stable tree Message-ID: References: <162082148164230@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <162082148164230@kroah.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Hi Greg, [disclaimer, just commenting as a bystander, noticing this failed apply] On Wed, May 12, 2021 at 02:11:21PM +0200, gregkh@linuxfoundation.org wrote: > > The patch below does not apply to the 5.12-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to . > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From 34e5b01186858b36c4d7c87e1a025071e8e2401f Mon Sep 17 00:00:00 2001 > From: Xin Long > Date: Mon, 3 May 2021 05:11:42 +0800 > Subject: [PATCH] sctp: delay auto_asconf init until binding the first addr > > As Or Cohen described: > > If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock > held and sp->do_auto_asconf is true, then an element is removed > from the auto_asconf_splist without any proper locking. > > This can happen in the following functions: > 1. In sctp_accept, if sctp_sock_migrate fails. > 2. In inet_create or inet6_create, if there is a bpf program > attached to BPF_CGROUP_INET_SOCK_CREATE which denies > creation of the sctp socket. > > This patch is to fix it by moving the auto_asconf init out of > sctp_init_sock(), by which inet_create()/inet6_create() won't > need to operate it in sctp_destroy_sock() when calling > sk_common_release(). > > It also makes more sense to do auto_asconf init while binding the > first addr, as auto_asconf actually requires an ANY addr bind, > see it in sctp_addr_wq_timeout_handler(). > > This addresses CVE-2021-23133. > > Fixes: 610236587600 ("bpf: Add new cgroup attach type to enable sock modifications") > Reported-by: Or Cohen > Signed-off-by: Xin Long > Signed-off-by: David S. Miller > > diff --git a/net/sctp/socket.c b/net/sctp/socket.c > index 76a388b5021c..40f9f6c4a0a1 100644 > --- a/net/sctp/socket.c > +++ b/net/sctp/socket.c > @@ -357,6 +357,18 @@ static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt, > return af; > } > > +static void sctp_auto_asconf_init(struct sctp_sock *sp) > +{ > + struct net *net = sock_net(&sp->inet.sk); > + > + if (net->sctp.default_auto_asconf) { > + spin_lock(&net->sctp.addr_wq_lock); > + list_add_tail(&sp->auto_asconf_list, &net->sctp.auto_asconf_splist); > + spin_unlock(&net->sctp.addr_wq_lock); > + sp->do_auto_asconf = 1; > + } > +} > + > /* Bind a local address either to an endpoint or to an association. */ > static int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len) > { > @@ -418,8 +430,10 @@ static int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len) > return -EADDRINUSE; > > /* Refresh ephemeral port. */ > - if (!bp->port) > + if (!bp->port) { > bp->port = inet_sk(sk)->inet_num; > + sctp_auto_asconf_init(sp); > + } > > /* Add the address to the bind address list. > * Use GFP_ATOMIC since BHs will be disabled. > @@ -4993,19 +5007,6 @@ static int sctp_init_sock(struct sock *sk) > sk_sockets_allocated_inc(sk); > sock_prot_inuse_add(net, sk->sk_prot, 1); > > - /* Nothing can fail after this block, otherwise > - * sctp_destroy_sock() will be called without addr_wq_lock held > - */ > - if (net->sctp.default_auto_asconf) { > - spin_lock(&sock_net(sk)->sctp.addr_wq_lock); > - list_add_tail(&sp->auto_asconf_list, > - &net->sctp.auto_asconf_splist); > - sp->do_auto_asconf = 1; > - spin_unlock(&sock_net(sk)->sctp.addr_wq_lock); > - } else { > - sp->do_auto_asconf = 0; > - } > - > local_bh_enable(); > > return 0; > @@ -9401,6 +9402,8 @@ static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk, > return err; > } > > + sctp_auto_asconf_init(newsp); > + > /* Move any messages in the old socket's receive queue that are for the > * peeled off association to the new socket's receive queue. > */ > Before applying this patch one needs to revert first b166a20b07382b8bc1dcee2a448715c9c2c81b5b . So first apply 01bfe5e8e428 ("Revert "net/sctp: fix race condition in sctp_destroy_sock"") and then apply 34e5b0118685 ("sctp: delay auto_asconf init until binding the first addr"). Regards, Salvatore