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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 A417CC32771 for ; Fri, 24 Jan 2020 11:41:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7BB112075D for ; Fri, 24 Jan 2020 11:41:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579866078; bh=RsSscILTKOs8mlW0g1H+l53z9HZnW/+PEIyKsx4W3Ns=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wGhI4kMunjy6AZej9f/jSVtD+XH/B5cz+a6rbItu3fvcQnMKck8/a0WJtTNnIcnqE NTj+CbEU6wclRIFzdltQDI8wEQVq9Bbd8xhwk2QMs1qGvtpOV3NXqoWYBnnn3yHCjv 9RQ6QI+mkWFQ67xtvaO8m+NtEJuhu6madtgzM6uo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391930AbgAXLlR (ORCPT ); Fri, 24 Jan 2020 06:41:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:56928 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390797AbgAXLTc (ORCPT ); Fri, 24 Jan 2020 06:19:32 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (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 619C320704; Fri, 24 Jan 2020 11:19:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864771; bh=RsSscILTKOs8mlW0g1H+l53z9HZnW/+PEIyKsx4W3Ns=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qMcxSYPBnDMEIcUa5nU8aSAtVxAMTJOJIf/cx+HE6Wkjohyd4lhQWgXx3MhPxwRg6 XIZ3nb+Cei2v45+mYahOJJ++2SjtcWHYUvyyHEgJZyHWVfC9ymZdQZhBVTEAHsyngZ nUK3egjsW9U9GcRCOYWC55vFYZpZQ0mGsKmDAYgc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Laight , Willem de Bruijn , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 338/639] packet: in recvmsg msg_name return at least sizeof sockaddr_ll Date: Fri, 24 Jan 2020 10:28:28 +0100 Message-Id: <20200124093129.467118520@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@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: Willem de Bruijn [ Upstream commit b2cf86e1563e33a14a1c69b3e508d15dc12f804c ] Packet send checks that msg_name is at least sizeof sockaddr_ll. Packet recv must return at least this length, so that its output can be passed unmodified to packet send. This ceased to be true since adding support for lladdr longer than sll_addr. Since, the return value uses true address length. Always return at least sizeof sockaddr_ll, even if address length is shorter. Zero the padding bytes. Change v1->v2: do not overwrite zeroed padding again. use copy_len. Fixes: 0fb375fb9b93 ("[AF_PACKET]: Allow for > 8 byte hardware addresses.") Suggested-by: David Laight Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ac65e66d1d727..60ba18a4bb0ff 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3371,20 +3371,29 @@ static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, sock_recv_ts_and_drops(msg, sk, skb); if (msg->msg_name) { + int copy_len; + /* If the address length field is there to be filled * in, we fill it in now. */ if (sock->type == SOCK_PACKET) { __sockaddr_check_size(sizeof(struct sockaddr_pkt)); msg->msg_namelen = sizeof(struct sockaddr_pkt); + copy_len = msg->msg_namelen; } else { struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr); + copy_len = msg->msg_namelen; + if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { + memset(msg->msg_name + + offsetof(struct sockaddr_ll, sll_addr), + 0, sizeof(sll->sll_addr)); + msg->msg_namelen = sizeof(struct sockaddr_ll); + } } - memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, - msg->msg_namelen); + memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); } if (pkt_sk(sk)->auxdata) { -- 2.20.1