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 54CCA142911; Thu, 13 Jun 2024 11:44:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718279089; cv=none; b=GF06uYniTUhGoZGKYnH93wk6tv2xwwrQNCUNJMJAerHGRsCWSjME1CXUbgsa7ASpw70ma4JBaEQv86BqPNrgTy1Br6bKlWsyDvy8m8zA/CfflX8Hvsn2f5/ELPOP1PlWp6LoXoebphUmNc95fdXHGNPXraYxRFrVLYT1SiH7p9c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718279089; c=relaxed/simple; bh=FQS4ZOJlri7LL5Cp8F2gswHEfFtfb//Q4CJBEdGXUdM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Emzveys0PPhXsyQjbEi/02JuzXhlIZP2vSrbqvlOxmaV1MKQo7qZhcmUnJ6xlJRVTZOCrXrY161+ll+ez+5ew0T4FKDkaQUcMktFle6b8DLXSHToMGZNjgNKOtvHpUYQ44ZtDTnd7ZDibfe/nhXKudeP+tQ2omwrt9yuBIa3A9A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=uA3hZgD0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="uA3hZgD0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AFB4C2BBFC; Thu, 13 Jun 2024 11:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718279089; bh=FQS4ZOJlri7LL5Cp8F2gswHEfFtfb//Q4CJBEdGXUdM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uA3hZgD0RBTFBd+KtamxkKlFGibqtKcyy1rBtROUM0205t+USD8WrTq/2RrqzYVIV QLqEitAl1Scbo7bYXVLZuQksAbjq+S66nvAu7flGNDKUt6+MIJ03e/RXw+wDACFL+C Ii55jajm4e8iRdND6T7FxBGM3cGDnBKbBzRF9e84= From: Greg Kroah-Hartman To: stable@vger.kernel.org, netfilter-devel@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pablo Neira Ayuso , Florian Westphal Subject: [PATCH 4.19 171/213] netfilter: nf_tables: fix GC transaction races with netns and netlink event exit path Date: Thu, 13 Jun 2024 13:33:39 +0200 Message-ID: <20240613113234.580337363@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240613113227.969123070@linuxfoundation.org> References: <20240613113227.969123070@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pablo Neira Ayuso commit 6a33d8b73dfac0a41f3877894b38082bd0c9a5bc upstream. Netlink event path is missing a synchronization point with GC transactions. Add GC sequence number update to netns release path and netlink event path, any GC transaction losing race will be discarded. Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_tables_api.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -6899,6 +6899,22 @@ void nft_trans_gc_queue_sync_done(struct } EXPORT_SYMBOL_GPL(nft_trans_gc_queue_sync_done); +static unsigned int nft_gc_seq_begin(struct nftables_pernet *nft_net) +{ + unsigned int gc_seq; + + /* Bump gc counter, it becomes odd, this is the busy mark. */ + gc_seq = READ_ONCE(nft_net->gc_seq); + WRITE_ONCE(nft_net->gc_seq, ++gc_seq); + + return gc_seq; +} + +static void nft_gc_seq_end(struct nftables_pernet *nft_net, unsigned int gc_seq) +{ + WRITE_ONCE(nft_net->gc_seq, ++gc_seq); +} + static int nf_tables_commit(struct net *net, struct sk_buff *skb) { struct nftables_pernet *nft_net = net_generic(net, nf_tables_net_id); @@ -6953,9 +6969,7 @@ static int nf_tables_commit(struct net * while (++nft_net->base_seq == 0) ; - /* Bump gc counter, it becomes odd, this is the busy mark. */ - gc_seq = READ_ONCE(nft_net->gc_seq); - WRITE_ONCE(nft_net->gc_seq, ++gc_seq); + gc_seq = nft_gc_seq_begin(nft_net); /* step 3. Start new generation, rules_gen_X now in use. */ net->nft.gencursor = nft_gencursor_next(net); @@ -7083,7 +7097,7 @@ static int nf_tables_commit(struct net * nf_tables_commit_release(net); nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN); - WRITE_ONCE(nft_net->gc_seq, ++gc_seq); + nft_gc_seq_end(nft_net, gc_seq); mutex_unlock(&nft_net->commit_mutex); return 0; @@ -7898,11 +7912,19 @@ static int __net_init nf_tables_init_net static void __net_exit nf_tables_exit_net(struct net *net) { struct nftables_pernet *nft_net = net_generic(net, nf_tables_net_id); + unsigned int gc_seq; mutex_lock(&nft_net->commit_mutex); + + gc_seq = nft_gc_seq_begin(nft_net); + if (!list_empty(&nft_net->commit_list)) __nf_tables_abort(net); + __nft_release_tables(net); + + nft_gc_seq_end(nft_net, gc_seq); + mutex_unlock(&nft_net->commit_mutex); WARN_ON_ONCE(!list_empty(&nft_net->tables)); }