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=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 88FF8C3F2D1 for ; Tue, 3 Mar 2020 18:00:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B56E20728 for ; Tue, 3 Mar 2020 18:00:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258450; bh=G4QSvPGFRpe0qgz7VhN+mv+kHRd9FUCfvTd2y2Cud9k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1Pv5TOxFdGialACJk5a0Vmo0PNSo7zUgPQjwciEg64sX9gzmbxlmdxHStqwkC6s5d ndmCwXqxqy0MUiVG0frD+GoIWPeuEM8SRcGh6t7UZpJyWQgH1d1GJ0uiy8nnJW8lxZ BfmYE6yvpxkUXlZvYP3L0D0MW5tXS2iomP4asKdg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387849AbgCCSAt (ORCPT ); Tue, 3 Mar 2020 13:00:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:44642 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733081AbgCCSAq (ORCPT ); Tue, 3 Mar 2020 13:00:46 -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 0A12820656; Tue, 3 Mar 2020 18:00:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258445; bh=G4QSvPGFRpe0qgz7VhN+mv+kHRd9FUCfvTd2y2Cud9k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T6mugbwA1Q6wEfy/HzHqg2JOLdbJM8gFQcaOh1pyf2OmvCZoTj0GlKp4mfTHhYI+f BzHulAWUrAidQhT3/5sv7IqFNIsP7sh1y7/o3NZhRqFMNobDWJqtBcWGFXJn0GOpXb jj9J7W28j1C05oc9fyGcBZIzgu1RAoJCWRbxJqzI= 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 4.19 51/87] vhost: Check docket sk_family instead of call getname Date: Tue, 3 Mar 2020 18:43:42 +0100 Message-Id: <20200303174354.941065895@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174349.075101355@linuxfoundation.org> References: <20200303174349.075101355@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 @@ -1187,10 +1187,6 @@ 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); @@ -1203,11 +1199,7 @@ 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; }