From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 55FC311703 for ; Mon, 21 Aug 2023 19:55:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BECA4C433C8; Mon, 21 Aug 2023 19:55:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1692647737; bh=rQgHTJSY07SYNiK/m8K6gwE8ld+M0KAuDYu8h4Yd2D0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zLEKZp2cL/ikre5GgHiS9sUIYaIUN24tsSaaOQ5Up+/HnQQ3bsSYstBLY9gGYwUgY ryKLHA7L4pMbBXkJWgG9Y67HlCF5jxwFvbjMIkGsmRJaMWMKxxgf06f3e1hwp6vJiX 0GEWFMeT+C7mECfeTLbAznxR/k1Jr9O+EurJYHDY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Florian Westphal , Sasha Levin Subject: [PATCH 6.1 120/194] netfilter: nf_tables: fix false-positive lockdep splat Date: Mon, 21 Aug 2023 21:41:39 +0200 Message-ID: <20230821194127.980951276@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230821194122.695845670@linuxfoundation.org> References: <20230821194122.695845670@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Florian Westphal [ Upstream commit b9f052dc68f69dac89fe1e24693354c033daa091 ] ->abort invocation may cause splat on debug kernels: WARNING: suspicious RCU usage net/netfilter/nft_set_pipapo.c:1697 suspicious rcu_dereference_check() usage! [..] rcu_scheduler_active = 2, debug_locks = 1 1 lock held by nft/133554: [..] (nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid [..] lockdep_rcu_suspicious+0x1ad/0x260 nft_pipapo_abort+0x145/0x180 __nf_tables_abort+0x5359/0x63d0 nf_tables_abort+0x24/0x40 nfnetlink_rcv+0x1a0a/0x22c0 netlink_unicast+0x73c/0x900 netlink_sendmsg+0x7f0/0xc20 ____sys_sendmsg+0x48d/0x760 Transaction mutex is held, so parallel updates are not possible. Switch to _protected and check mutex is held for lockdep enabled builds. Fixes: 212ed75dc5fb ("netfilter: nf_tables: integrate pipapo into commit protocol") Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/nft_set_pipapo.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index a81829c10feab..32cfd0a84b0e2 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -1665,6 +1665,17 @@ static void nft_pipapo_commit(const struct nft_set *set) priv->clone = new_clone; } +static bool nft_pipapo_transaction_mutex_held(const struct nft_set *set) +{ +#ifdef CONFIG_PROVE_LOCKING + const struct net *net = read_pnet(&set->net); + + return lockdep_is_held(&nft_pernet(net)->commit_mutex); +#else + return true; +#endif +} + static void nft_pipapo_abort(const struct nft_set *set) { struct nft_pipapo *priv = nft_set_priv(set); @@ -1673,7 +1684,7 @@ static void nft_pipapo_abort(const struct nft_set *set) if (!priv->dirty) return; - m = rcu_dereference(priv->match); + m = rcu_dereference_protected(priv->match, nft_pipapo_transaction_mutex_held(set)); new_clone = pipapo_clone(m); if (IS_ERR(new_clone)) -- 2.40.1