From patchwork Mon Feb 21 08:48:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 544919 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 23C9DC433F5 for ; Mon, 21 Feb 2022 09:10:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347518AbiBUJKe (ORCPT ); Mon, 21 Feb 2022 04:10:34 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:60540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347910AbiBUJJu (ORCPT ); Mon, 21 Feb 2022 04:09:50 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E38F1C937; Mon, 21 Feb 2022 01:02:13 -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 dfw.source.kernel.org (Postfix) with ESMTPS id EDAF060FB6; Mon, 21 Feb 2022 09:02:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2F19C340E9; Mon, 21 Feb 2022 09:02:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645434132; bh=DzmpeJoKaV7iILY+sZu/gI4+52iSEawvhB6YbzA78R0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KtZksYF68xcnsitzudtCKmxyBjxIBVjXgPVMANjU3qmfGW5qW+V82jeV21HisLHnb 01//wF5WGmo4DelkrCqMO//A7eTWloUw+vGQrztMggk2EUB5y4wHBpvbrWAsAv43kU vzusR9V8xLtVffq7xr64ouYrnSxHUJoY7rABq5Ps= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Norbert Slusarek , Thadeu Lima de Souza Cascardo , Oliver Hartkopp , Marc Kleine-Budde Subject: [PATCH 5.10 006/121] can: isotp: prevent race between isotp_bind() and isotp_setsockopt() Date: Mon, 21 Feb 2022 09:48:18 +0100 Message-Id: <20220221084921.366910498@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220221084921.147454846@linuxfoundation.org> References: <20220221084921.147454846@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Norbert Slusarek commit 2b17c400aeb44daf041627722581ade527bb3c1d upstream. 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: 921ca574cd38 ("can: isotp: add SF_BROADCAST support for functional addressing") 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 Signed-off-by: Greg Kroah-Hartman --- net/can/isotp.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -1193,16 +1193,13 @@ static int isotp_getname(struct socket * 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; @@ -1277,6 +1274,22 @@ static int isotp_setsockopt(struct socke 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) {