From patchwork Wed Jun 2 12:44:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 453053 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=-16.8 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=unavailable 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 030B8C47092 for ; Wed, 2 Jun 2021 12:44:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5CCB613D2 for ; Wed, 2 Jun 2021 12:44:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230090AbhFBMq0 (ORCPT ); Wed, 2 Jun 2021 08:46:26 -0400 Received: from mail.netfilter.org ([217.70.188.207]:41576 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229916AbhFBMqV (ORCPT ); Wed, 2 Jun 2021 08:46:21 -0400 Received: from localhost.localdomain (unknown [90.77.255.23]) by mail.netfilter.org (Postfix) with ESMTPSA id AF061641DB; Wed, 2 Jun 2021 14:43:30 +0200 (CEST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org Subject: [PATCH net 2/2] netfilter: nfnetlink_cthelper: hit EBUSY on updates if size mismatches Date: Wed, 2 Jun 2021 14:44:30 +0200 Message-Id: <20210602124430.10863-3-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210602124430.10863-1-pablo@netfilter.org> References: <20210602124430.10863-1-pablo@netfilter.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The private helper data size cannot be updated. However, updates that contain NFCTH_PRIV_DATA_LEN might bogusly hit EBUSY even if the size is the same. Fixes: 12f7a505331e ("netfilter: add user-space connection tracking helper infrastructure") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink_cthelper.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c index 322ac5dd5402..752b10cae524 100644 --- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -380,10 +380,14 @@ static int nfnl_cthelper_update(const struct nlattr * const tb[], struct nf_conntrack_helper *helper) { + u32 size; int ret; - if (tb[NFCTH_PRIV_DATA_LEN]) - return -EBUSY; + if (tb[NFCTH_PRIV_DATA_LEN]) { + size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN])); + if (size != helper->data_len) + return -EBUSY; + } if (tb[NFCTH_POLICY]) { ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]);