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 32D9DC433F5 for ; Wed, 16 Feb 2022 07:22:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229968AbiBPHWy (ORCPT ); Wed, 16 Feb 2022 02:22:54 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:38338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230002AbiBPHWw (ORCPT ); Wed, 16 Feb 2022 02:22:52 -0500 X-Greylist: delayed 572 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 15 Feb 2022 23:22:36 PST Received: from mo4-p00-ob.smtp.rzone.de (mo4-p00-ob.smtp.rzone.de [81.169.146.216]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C25EAD5 for ; Tue, 15 Feb 2022 23:22:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1644993151; s=strato-dkim-0002; d=hartkopp.net; h=Message-Id:Date:Subject:Cc:To:From:Cc:Date:From:Subject:Sender; bh=XW7Vp0hhhdyNox3vT96fEpwyFA9OtgyB00lFK37Dzyw=; b=Sd/s4sCa+p1qIJYYMwuXDmvV8DLVSjQZSMq41baUUkkM7d0DQjs0UIguQhvS5XSyzg ozP2aBU5rs/+5Wj/LK7VWXr0by066Vr6cLe/l2/x2stf+G8Q3J1rwVbhBdaorjno/Skk zFZIGpWFvWr10lj/wJumdf4hyLqAlqW36rQnb0YFbj7hsstut/sTxh/qyISKOfy9SsFO saYcf8sEmasRA64rh35LFNn0LQe+6rxQHmBd0QQjSOFCRoNMo67Xp22dtcAreeFzoeMI YBpbmdG+rzwxQwuEkWG15D0rt33H+LiIur01CZIDwOcEpQZCqzHuNIzXj+hf7I3hky22 H5xg== Authentication-Results: strato.com; dkim=none X-RZG-AUTH: ":P2MHfkW8eP4Mre39l357AZT/I7AY/7nT2yrDxb8mjGrp7owjzFK3JbFk1mS/xvEBL7X5sbo3UIh9IyLecSWJafUvprl4" X-RZG-CLASS-ID: mo00 Received: from silver.lan by smtp.strato.de (RZmta 47.39.0 AUTH) with ESMTPSA id L7379cy1G6WUfoi (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Wed, 16 Feb 2022 07:32:30 +0100 (CET) From: Oliver Hartkopp To: gregkh@linuxfoundation.org, stable@vger.kernel.org Cc: Oliver Hartkopp , Norbert Slusarek , Thadeu Lima de Souza Cascardo , Marc Kleine-Budde Subject: [BACKPORT stable Linux-5.10.y 1/2] can: isotp: prevent race between isotp_bind() and isotp_setsockopt() Date: Wed, 16 Feb 2022 07:31:36 +0100 Message-Id: <20220216063137.2023-1-socketcan@hartkopp.net> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Upstream commit 2b17c400aeb44daf041627722581ade527bb3c1d The fixes tag of the uptream patch points to commit 921ca574cd38 ("can: isotp: add SF_BROADCAST support for functional addressing") which showed up in Linux 5.11 but the described issue already existed in Linux 5.10. Norbert Slusarek writes: A race condition was found in isotp_setsockopt() which allows to change socket options after the socket was bound. For the specific case of SF_BROADCAST support, this might lead to possible use-after-free because can_rx_unregister() is not called. Checking for the flag under the socket lock in isotp_bind() and taking the lock in isotp_setsockopt() fixes the issue. Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol") Link: https://lore.kernel.org/r/trinity-e6ae9efa-9afb-4326-84c0-f3609b9b8168-1620773528307@3c-app-gmx-bs06 Reported-by: Norbert Slusarek Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Norbert Slusarek Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp --- net/can/isotp.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/net/can/isotp.c b/net/can/isotp.c index 37db4d232313..3f11d2b314b6 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -1191,20 +1191,17 @@ static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer) addr->can_addr.tp.tx_id = so->txid; return ISOTP_MIN_NAMELEN; } -static int isotp_setsockopt(struct socket *sock, int level, int optname, +static int isotp_setsockopt_locked(struct socket *sock, int level, int optname, sockptr_t optval, unsigned int optlen) { struct sock *sk = sock->sk; struct isotp_sock *so = isotp_sk(sk); int ret = 0; - if (level != SOL_CAN_ISOTP) - return -EINVAL; - if (so->bound) return -EISCONN; switch (optname) { case CAN_ISOTP_OPTS: @@ -1275,10 +1272,26 @@ static int isotp_setsockopt(struct socket *sock, int level, int optname, } return ret; } +static int isotp_setsockopt(struct socket *sock, int level, int optname, + sockptr_t optval, unsigned int optlen) + +{ + struct sock *sk = sock->sk; + int ret; + + if (level != SOL_CAN_ISOTP) + return -EINVAL; + + lock_sock(sk); + ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen); + release_sock(sk); + return ret; +} + static int isotp_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { struct sock *sk = sock->sk; struct isotp_sock *so = isotp_sk(sk); -- 2.30.2