From patchwork Thu Dec 10 14:27:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 341852 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=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 72F88C4167B for ; Thu, 10 Dec 2020 18:31:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F77523E21 for ; Thu, 10 Dec 2020 18:31:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390802AbgLJOeU (ORCPT ); Thu, 10 Dec 2020 09:34:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:42308 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390796AbgLJOeO (ORCPT ); Thu, 10 Dec 2020 09:34:14 -0500 From: Greg Kroah-Hartman Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Naresh Kamboju , Florian Westphal , Pablo Neira Ayuso Subject: [PATCH 4.19 38/39] netfilter: nf_tables: avoid false-postive lockdep splat Date: Thu, 10 Dec 2020 15:27:17 +0100 Message-Id: <20201210142604.165606801@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201210142602.272595094@linuxfoundation.org> References: <20201210142602.272595094@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Florian Westphal commit c0700dfa2cae44c033ed97dade8a2679c7d22a9d upstream. There are reports wrt lockdep splat in nftables, e.g.: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 31416 at net/netfilter/nf_tables_api.c:622 lockdep_nfnl_nft_mutex_not_held+0x28/0x38 [nf_tables] ... These are caused by an earlier, unrelated bug such as a n ABBA deadlock in a different subsystem. In such an event, lockdep is disabled and lockdep_is_held returns true unconditionally. This then causes the WARN() in nf_tables. Make the WARN conditional on lockdep still active to avoid this. Fixes: f102d66b335a417 ("netfilter: nf_tables: use dedicated mutex to guard transactions") Reported-by: Naresh Kamboju Link: https://lore.kernel.org/linux-kselftest/CA+G9fYvFUpODs+NkSYcnwKnXm62tmP=ksLeBPmB+KFrB2rvCtQ@mail.gmail.com/ Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_tables_api.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -532,7 +532,8 @@ static void nft_request_module(struct ne static void lockdep_nfnl_nft_mutex_not_held(void) { #ifdef CONFIG_PROVE_LOCKING - WARN_ON_ONCE(lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES)); + if (debug_locks) + WARN_ON_ONCE(lockdep_nfnl_is_held(NFNL_SUBSYS_NFTABLES)); #endif }