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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 59262C54FD0 for ; Thu, 23 Apr 2020 23:09:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4027320780 for ; Thu, 23 Apr 2020 23:09:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729080AbgDWXJl (ORCPT ); Thu, 23 Apr 2020 19:09:41 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50854 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728647AbgDWXG6 (ORCPT ); Thu, 23 Apr 2020 19:06:58 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jRkvk-0004xX-C2; Fri, 24 Apr 2020 00:06:52 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jRkvf-00E72P-P3; Fri, 24 Apr 2020 00:06:47 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Michael S. Tsirkin" , "=?UTF-8?q?Eugenio=20P=C3=A9rez?=" , syzbot+f2a62d07a5198c819c7b@syzkaller.appspotmail.com, "David S. Miller" Date: Fri, 24 Apr 2020 00:07:32 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 225/245] vhost: Check docket sk_family instead of call getname In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.83-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eugenio Pérez commit 42d84c8490f9f0931786f1623191fcab397c3d64 upstream. Doing so, we save one call to get data we already have in the struct. Also, since there is no guarantee that getname use sockaddr_ll parameter beyond its size, we add a little bit of security here. It should do not do beyond MAX_ADDR_LEN, but syzbot found that ax25_getname writes more (72 bytes, the size of full_sockaddr_ax25, versus 20 + 32 bytes of sockaddr_ll + MAX_ADDR_LEN in syzbot repro). Fixes: 3a4d5c94e9593 ("vhost_net: a kernel-level virtio server") Reported-by: syzbot+f2a62d07a5198c819c7b@syzkaller.appspotmail.com Signed-off-by: Eugenio Pérez Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller [bwh: Backported to 3.16: Also delete "uaddr_len" variable] Signed-off-by: Ben Hutchings --- --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -843,11 +843,7 @@ static int vhost_net_release(struct inod static struct socket *get_raw_socket(int fd) { - struct { - struct sockaddr_ll sa; - char buf[MAX_ADDR_LEN]; - } uaddr; - int uaddr_len = sizeof uaddr, r; + int r; struct socket *sock = sockfd_lookup(fd, &r); if (!sock) @@ -859,12 +855,7 @@ static struct socket *get_raw_socket(int goto err; } - r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, - &uaddr_len, 0); - if (r) - goto err; - - if (uaddr.sa.sll_family != AF_PACKET) { + if (sock->sk->sk_family != AF_PACKET) { r = -EPFNOSUPPORT; goto err; }