From patchwork Wed Jul 7 16:18:36 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: 471140 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,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 67180C07E9C for ; Wed, 7 Jul 2021 16:18:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5348161C99 for ; Wed, 7 Jul 2021 16:18:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230200AbhGGQVi (ORCPT ); Wed, 7 Jul 2021 12:21:38 -0400 Received: from mail.netfilter.org ([217.70.188.207]:55114 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230178AbhGGQVd (ORCPT ); Wed, 7 Jul 2021 12:21:33 -0400 Received: from localhost.localdomain (unknown [90.77.255.23]) by mail.netfilter.org (Postfix) with ESMTPSA id 2F54861836; Wed, 7 Jul 2021 18:18:40 +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 03/11] netfilter: nf_tables: Fix dereference of null pointer flow Date: Wed, 7 Jul 2021 18:18:36 +0200 Message-Id: <20210707161844.20827-4-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210707161844.20827-1-pablo@netfilter.org> References: <20210707161844.20827-1-pablo@netfilter.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Colin Ian King In the case where chain->flags & NFT_CHAIN_HW_OFFLOAD is false then nft_flow_rule_create is not called and flow is NULL. The subsequent error handling execution via label err_destroy_flow_rule will lead to a null pointer dereference on flow when calling nft_flow_rule_destroy. Since the error path to err_destroy_flow_rule has to cater for null and non-null flows, only call nft_flow_rule_destroy if flow is non-null to fix this issue. Addresses-Coverity: ("Explicity null dereference") Fixes: 3c5e44622011 ("netfilter: nf_tables: memleak in hw offload abort path") Signed-off-by: Colin Ian King Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 390d4466567f..de182d1f7c4e 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3446,7 +3446,8 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, return 0; err_destroy_flow_rule: - nft_flow_rule_destroy(flow); + if (flow) + nft_flow_rule_destroy(flow); err_release_rule: nf_tables_rule_release(&ctx, rule); err_release_expr: