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 X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 906BEC433DB for ; Wed, 24 Mar 2021 19:48:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E23A61A1B for ; Wed, 24 Mar 2021 19:48:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237964AbhCXTr1 convert rfc822-to-8bit (ORCPT ); Wed, 24 Mar 2021 15:47:27 -0400 Received: from lithops.sigma-star.at ([195.201.40.130]:50594 "EHLO lithops.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237930AbhCXTrV (ORCPT ); Wed, 24 Mar 2021 15:47:21 -0400 Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id F229A60A3588; Wed, 24 Mar 2021 20:47:19 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id MPWbdyruf1r2; Wed, 24 Mar 2021 20:47:19 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 9148960A0E19; Wed, 24 Mar 2021 20:47:19 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 9tXp6jET54E4; Wed, 24 Mar 2021 20:47:19 +0100 (CET) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id 6DD7F60A0723; Wed, 24 Mar 2021 20:47:19 +0100 (CET) Date: Wed, 24 Mar 2021 20:47:19 +0100 (CET) From: Richard Weinberger To: Kurt Van Dijck Cc: linux-can Message-ID: <972595778.112313.1616615239337.JavaMail.zimbra@nod.at> In-Reply-To: <20210324192746.GA7408@x1.vandijck-laurijssen.be> References: <1883346738.111675.1616599858539.JavaMail.zimbra@nod.at> <20210324190104.GB3342@x1.vandijck-laurijssen.be> <1135648123.112255.1616613706554.JavaMail.zimbra@nod.at> <20210324192746.GA7408@x1.vandijck-laurijssen.be> Subject: Re: PATCH: Breaking UAPI change? MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Originating-IP: [195.201.40.130] X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF78 (Linux)/8.8.12_GA_3809) Thread-Topic: PATCH: Breaking UAPI change? Thread-Index: eJ7i3wjaNjDddPEDkEt2BR/uTgRDKw== Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org Kurt, ----- Ursprüngliche Mail ----- > Happy testing? ;-) > commit 124900109ca88d29382ef2e2b848d3a2f9d67b98 > Author: Kurt Van Dijck > Date: Wed Mar 24 20:08:50 2021 > > can raw: don't increase provided name length > > The length of the buffer is known by the application, > not the kernel. Kernel is supposed to return only the > size of used bytes. > There is a minimum required size for the struct sockaddr_can > to be usefull for can_raw, so errors are returned when > the provided size is lower > > Signed-off-by: Kurt Van Dijck > > diff --git a/net/can/raw.c b/net/can/raw.c > index 6ec8aa1d0da4..00d352ae221e 100644 > --- a/net/can/raw.c > +++ b/net/can/raw.c > @@ -475,7 +475,7 @@ static int raw_getname(struct socket *sock, struct sockaddr > *uaddr, > if (peer) > return -EOPNOTSUPP; > > - memset(addr, 0, sizeof(*addr)); > + memset(addr, 0, CAN_REQUIRED_SIZE(*addr, ifindex)); can_ifindex? > addr->can_family = AF_CAN; > addr->can_ifindex = ro->ifindex; > > @@ -806,6 +806,10 @@ static int raw_recvmsg(struct socket *sock, struct msghdr > *msg, size_t size, > return sock_recv_errqueue(sk, msg, size, > SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE); > > + if (msg->name && msg->msg_namelen < msg->msg_name? > + CAN_REQUIRED_SIZE(struct sockaddr_can, ifindex)) > + return -EINVAL; > + With the above changes this -EINVAL always triggers. msg->msg_namelen is 0 in my case. The application does: socklen_t addrlen = sizeof(struct sockaddr_can); recvfrom(s, &frame, sizeof(struct can_frame), 0, (struct sockaddr *)&addr, &addrlen); Thanks, //richard