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 E95C679955; Mon, 8 Apr 2024 13:23:19 +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=1712582600; cv=none; b=hAKYmx2jIAZKtQtZiKoHa8oWsprK1hhVSJfmc7O0hgkqLCw3vItH+QK/xDuaZsyp0Nc1Ul2KB1gJbZZuKv4HzyCRr0FX8UtCV1OKOu5DhYwu5kSet+/yBC5mvd184uCYC50vtvwE1/pnGB+slZn0k1otroEppFxQJ0GzZJ3yqdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712582600; c=relaxed/simple; bh=auOb5L4ASL7DuuCh88X74wCWhmZuye7NRVCgtxQCGhQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RDL09YEgWWAGMTHiduhTDCUic+Bpxs2mzbXy9jqNtrPj+H3XbAcoUK4mCBj80zEC/v87sKiGndUxtNzUxr8Z+G8ZfjpHiMTRv7O3xfurDMHw7KCWFxICwQsjkDKPbdhNuQ1mSTY6l8TriQaHduBGoQjoxkd0NY01i0FZt8qJa70= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ympYsbAl; 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="ympYsbAl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C1C6C433C7; Mon, 8 Apr 2024 13:23:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712582599; bh=auOb5L4ASL7DuuCh88X74wCWhmZuye7NRVCgtxQCGhQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ympYsbAlMznESuGQ8eFjLC6FleYbRSgNfc4gcf5qwz1hzaEbWeF48ahY81nQol8aH R1+VlGrY2u7LtpI8cPuOPzmmswaKwaKSeqjEbwq13S861ySuczsEAI/LJ+MrXS95lZ 2bfXDlOx0YLx7tjuQJirL6rGm9cOTF8ecL6zkL4I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ziyang Xuan , Pablo Neira Ayuso Subject: [PATCH 6.8 089/273] netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get() Date: Mon, 8 Apr 2024 14:56:04 +0200 Message-ID: <20240408125312.068757558@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240408125309.280181634@linuxfoundation.org> References: <20240408125309.280181634@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ziyang Xuan commit 24225011d81b471acc0e1e315b7d9905459a6304 upstream. nft_unregister_flowtable_type() within nf_flow_inet_module_exit() can concurrent with __nft_flowtable_type_get() within nf_tables_newflowtable(). And thhere is not any protection when iterate over nf_tables_flowtables list in __nft_flowtable_type_get(). Therefore, there is pertential data-race of nf_tables_flowtables list entry. Use list_for_each_entry_rcu() to iterate over nf_tables_flowtables list in __nft_flowtable_type_get(), and use rcu_read_lock() in the caller nft_flowtable_type_get() to protect the entire type query process. Fixes: 3b49e2e94e6e ("netfilter: nf_tables: add flow table netlink frontend") Signed-off-by: Ziyang Xuan Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_tables_api.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8292,11 +8292,12 @@ static int nft_flowtable_parse_hook(cons return err; } +/* call under rcu_read_lock */ static const struct nf_flowtable_type *__nft_flowtable_type_get(u8 family) { const struct nf_flowtable_type *type; - list_for_each_entry(type, &nf_tables_flowtables, list) { + list_for_each_entry_rcu(type, &nf_tables_flowtables, list) { if (family == type->family) return type; } @@ -8308,9 +8309,13 @@ nft_flowtable_type_get(struct net *net, { const struct nf_flowtable_type *type; + rcu_read_lock(); type = __nft_flowtable_type_get(family); - if (type != NULL && try_module_get(type->owner)) + if (type != NULL && try_module_get(type->owner)) { + rcu_read_unlock(); return type; + } + rcu_read_unlock(); lockdep_nfnl_nft_mutex_not_held(); #ifdef CONFIG_MODULES