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 D3E85C2D0DB for ; Tue, 28 Jan 2020 14:44:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AACBA207FD for ; Tue, 28 Jan 2020 14:44:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580222662; bh=yWx+SyF8JNDr/KrEqZhljwIs9PAmmvfLfKF+FNV5/Gk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=u6YJ7STmbDFrrO4fbxm4Y63ha1gS+QqE2GyWBZO6J0/3QARtK0C45eZaR5K39drnG TdizTAWrM2WH2vdSvoB2paMq6v9N7cKzKQ8P7Ts+GzHtpVaRiSHbxSUoy8YMdtA/Uf yaCmVmQin8InHgxZhMbalFd6vR2vU8s0nk2hXUpc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727191AbgA1OK2 (ORCPT ); Tue, 28 Jan 2020 09:10:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:59300 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727923AbgA1OK1 (ORCPT ); Tue, 28 Jan 2020 09:10:27 -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 7818522522; Tue, 28 Jan 2020 14:10:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220626; bh=yWx+SyF8JNDr/KrEqZhljwIs9PAmmvfLfKF+FNV5/Gk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hB/pJ8aj1sbCkAP2Ktj6isP3jdgBFRAecl4RNqacfRuJPm+bkVLiMu8k2G55X9qcL 8BQYJ6I+ZkFTHrmHy9odFXkuCp7OuvHT67cBqSyaSj+epcjzoDzVCnS9s8vXp35oUk Lb7C8bm6R3QIyXUTPgHTvuNvtdoI0dEgG3k1jyVw= 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 4.4 083/183] packet: in recvmsg msg_name return at least sizeof sockaddr_ll Date: Tue, 28 Jan 2020 15:05:02 +0100 Message-Id: <20200128135838.223490325@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135829.486060649@linuxfoundation.org> References: <20200128135829.486060649@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 8b277658905f7..9de7e3e6edd30 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3309,20 +3309,29 @@ 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