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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 5B124C3F2C6 for ; Tue, 3 Mar 2020 17:56:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3880E20870 for ; Tue, 3 Mar 2020 17:56:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258174; bh=EJaw7nSihU84X6HW/kSe1Dq4ngkgNCk0RFoO+OkqYWU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0E90/vZhZElTJ+CvFsYkGDpKKXlOvpFxoyb1SgmclnFwcQlpfjN911g7PV6d1oK+q 73RRV0+iM8Kqko4mxfjF7ojG7hoa0Dp25CeYbi1wav0CLQwQhfT49q/+12+blxD03P T8KJlBHTkUEYdX2OfV+tiwr1d3vkzkw7jvXvJm0g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732857AbgCCR4N (ORCPT ); Tue, 3 Mar 2020 12:56:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:38110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732833AbgCCR4G (ORCPT ); Tue, 3 Mar 2020 12:56:06 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4F0EF20728; Tue, 3 Mar 2020 17:56:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258165; bh=EJaw7nSihU84X6HW/kSe1Dq4ngkgNCk0RFoO+OkqYWU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zypg5uvwalKTEuyQTI7sUe008ZlpTKd0440fNtfXwgfdocstRdWn4zMFW/ofdk8NW jiW46yUJKaz/sp5YBOCSud0KMecfne1TsDGrdy9JPlq1LV2Xh3F03mCR/ppSEyYjcm L27drFpnqyl4e9AXgmA3q6cN/2w6kcWweBKxWLEI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+f2a62d07a5198c819c7b@syzkaller.appspotmail.com, =?UTF-8?q?Eugenio=20P=C3=A9rez?= , "Michael S. Tsirkin" , "David S. Miller" Subject: [PATCH 5.4 089/152] vhost: Check docket sk_family instead of call getname Date: Tue, 3 Mar 2020 18:43:07 +0100 Message-Id: <20200303174312.678120325@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174302.523080016@linuxfoundation.org> References: <20200303174302.523080016@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Signed-off-by: Greg Kroah-Hartman --- drivers/vhost/net.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1414,10 +1414,6 @@ 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 r; struct socket *sock = sockfd_lookup(fd, &r); @@ -1430,11 +1426,7 @@ static struct socket *get_raw_socket(int goto err; } - r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, 0); - if (r < 0) - goto err; - - if (uaddr.sa.sll_family != AF_PACKET) { + if (sock->sk->sk_family != AF_PACKET) { r = -EPFNOSUPPORT; goto err; }