From patchwork Wed Dec 9 22:18:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 341711 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 BFD14C433FE for ; Wed, 9 Dec 2020 22:19:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 919D4238A0 for ; Wed, 9 Dec 2020 22:19:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388525AbgLIWTJ (ORCPT ); Wed, 9 Dec 2020 17:19:09 -0500 Received: from correo.us.es ([193.147.175.20]:32982 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388419AbgLIWTE (ORCPT ); Wed, 9 Dec 2020 17:19:04 -0500 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 1E784D2DA13 for ; Wed, 9 Dec 2020 23:18:10 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 0E1A1DA8F6 for ; Wed, 9 Dec 2020 23:18:10 +0100 (CET) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 0387DDA722; Wed, 9 Dec 2020 23:18:10 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id D6419DA73F; Wed, 9 Dec 2020 23:18:07 +0100 (CET) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Wed, 09 Dec 2020 23:18:07 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from localhost.localdomain (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPSA id A9D734265A5A; Wed, 9 Dec 2020 23:18:07 +0100 (CET) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org Subject: [PATCH net 3/4] netfilter: nftables: comment indirect serialization of commit_mutex with rtnl_mutex Date: Wed, 9 Dec 2020 23:18:09 +0100 Message-Id: <20201209221810.32504-4-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201209221810.32504-1-pablo@netfilter.org> References: <20201209221810.32504-1-pablo@netfilter.org> MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add an explicit comment in the code to describe the indirect serialization of the holders of the commit_mutex with the rtnl_mutex. Commit 90d2723c6d4c ("netfilter: nf_tables: do not hold reference on netdevice from preparation phase") already describes this, but a comment in this case is better for reference. Reported-by: Vladimir Oltean Reviewed-by: Vladimir Oltean Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index c2f59879a48d..9a080767667b 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1723,6 +1723,10 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net, } nla_strlcpy(ifname, attr, IFNAMSIZ); + /* nf_tables_netdev_event() is called under rtnl_mutex, this is + * indirectly serializing all the other holders of the commit_mutex with + * the rtnl_mutex. + */ dev = __dev_get_by_name(net, ifname); if (!dev) { err = -ENOENT;