From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19278C636CC for ; Fri, 3 Feb 2023 10:33:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233499AbjBCKdG (ORCPT ); Fri, 3 Feb 2023 05:33:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231764AbjBCKck (ORCPT ); Fri, 3 Feb 2023 05:32:40 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ABF0C9DCA5 for ; Fri, 3 Feb 2023 02:30:48 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 63ECFB82A5F for ; Fri, 3 Feb 2023 10:30:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99993C433D2; Fri, 3 Feb 2023 10:30:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675420246; bh=uPq7Wf0BAst31h+ne+xR4yufJWhRlnHNIbbsKLdDizY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZbKBhA7BA/obcpBrsuFbpIZqOcaOWxihnAtGg0TP5TuZviIxhGnXCycTgKMXHFT9v 48plCqj1nl0bquG/fQMS6upfgq72SgPU7fbxEScLjl8Amx69DtQSllCUXgnBfd5QuN GdjlBLPOLJx7DO3Y+aAIHxg6SnfonfoPWUbhcNss= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.4 089/134] netlink: annotate data races around sk_state Date: Fri, 3 Feb 2023 11:13:14 +0100 Message-Id: <20230203101027.851791811@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230203101023.832083974@linuxfoundation.org> References: <20230203101023.832083974@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit 9b663b5cbb15b494ef132a3c937641c90646eb73 ] netlink_getsockbyportid() reads sk_state while a concurrent netlink_connect() can change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/netlink/af_netlink.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index d398623d8275..a232fcbd721c 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1080,7 +1080,8 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr, return -EINVAL; if (addr->sa_family == AF_UNSPEC) { - sk->sk_state = NETLINK_UNCONNECTED; + /* paired with READ_ONCE() in netlink_getsockbyportid() */ + WRITE_ONCE(sk->sk_state, NETLINK_UNCONNECTED); /* dst_portid and dst_group can be read locklessly */ WRITE_ONCE(nlk->dst_portid, 0); WRITE_ONCE(nlk->dst_group, 0); @@ -1104,7 +1105,8 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr, err = netlink_autobind(sock); if (err == 0) { - sk->sk_state = NETLINK_CONNECTED; + /* paired with READ_ONCE() in netlink_getsockbyportid() */ + WRITE_ONCE(sk->sk_state, NETLINK_CONNECTED); /* dst_portid and dst_group can be read locklessly */ WRITE_ONCE(nlk->dst_portid, nladdr->nl_pid); WRITE_ONCE(nlk->dst_group, ffs(nladdr->nl_groups)); @@ -1156,8 +1158,8 @@ static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) /* Don't bother queuing skb if kernel socket has no input function */ nlk = nlk_sk(sock); - /* dst_portid can be changed in netlink_connect() */ - if (sock->sk_state == NETLINK_CONNECTED && + /* dst_portid and sk_state can be changed in netlink_connect() */ + if (READ_ONCE(sock->sk_state) == NETLINK_CONNECTED && READ_ONCE(nlk->dst_portid) != nlk_sk(ssk)->portid) { sock_put(sock); return ERR_PTR(-ECONNREFUSED); -- 2.39.0