From patchwork Fri Mar 4 20:44:16 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Willem de Bruijn X-Patchwork-Id: 592208 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id B2A3C1402D8 for ; Sat, 5 Mar 2016 07:44:38 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=DEvDKMkg; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759903AbcCDUog (ORCPT ); Fri, 4 Mar 2016 15:44:36 -0500 Received: from mail-qg0-f66.google.com ([209.85.192.66]:34144 "EHLO mail-qg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759087AbcCDUoZ (ORCPT ); Fri, 4 Mar 2016 15:44:25 -0500 Received: by mail-qg0-f66.google.com with SMTP id t4so4109938qge.1; Fri, 04 Mar 2016 12:44:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=vp/xLtmhcEI7BjMoOrOR7gg/POyQ81nl0rIUfesJb+w=; b=DEvDKMkgZ0qI/yXEVg5rY2LJxuXiO6LRFtuciP5rKzUMVuD/r72GkII7UpfySYREfH BJOTVmGDZjnJFM8GxJBlutJL7Kxf4UFZhICA3Y8BZnJDO+Tde4Hqe+2uCB/k8FqsBZ0H ORYz1k/y0wSjRQVPY6wuqdMmMYdVHNjS3Tc+ly1CAgj3t5Pk6dm/22XAjWYngsvhiQM0 PgLmyjiCjtoX/YyDozROiVZi7cO5C+N7gGIXBAEiTp5blcXvbFEKAmlwaDQ1SMSkCk4Y xE8f5SV/4kD3keAoRTpsjL3yiS8CLA7anyE7zDHBygIADlGYRM0WDlyMLOKssv3uMWba DeWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=vp/xLtmhcEI7BjMoOrOR7gg/POyQ81nl0rIUfesJb+w=; b=jBYYir02biFIQtI1jjAYISJW16FHmvSdManjrpw3mOI8EppEQcoIrURf+FjHwaq6JS knxmkYYzzIb1vRkxAV02kSa16OBg2RjfLcBqOLbyQVpp89hVkRV0HtTvx0uosw/fQEit qoGUyaNqwLLcAL1B6iYT/Xhhi/5bR4lnchJUAZcUbsyPuo7rGQ83Z4jO2EcBS+lIbMCv 00zJBmL6W1aNZwNH9mnJnDfqB++WeFNdxmciZ+g2gcxjKybfc8KYFpz2Thad/PaYvXdk bR+z49qwn5NB6wKQCBdEpv+ZVft5S9T7nUxMa+Cbipys7cekt0bpcH6/0EgjpF8Z+C8M acuw== X-Gm-Message-State: AD7BkJJCc6PIBfmUOAaeMz92w2VgvNjxiitAy9ZIhUyf45Ta8KmkGXuVcW0LDal7i7tQuw== X-Received: by 10.140.94.106 with SMTP id f97mr12579915qge.95.1457124264107; Fri, 04 Mar 2016 12:44:24 -0800 (PST) Received: from gopher.nyc.corp.google.com ([172.29.18.107]) by smtp.gmail.com with ESMTPSA id q198sm2378858qhb.16.2016.03.04.12.44.22 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 04 Mar 2016 12:44:23 -0800 (PST) From: Willem de Bruijn To: netdev@vger.kernel.org Cc: davem@davemloft.net, alan@linux.intel.com, hessu@hes.iki.fi, martin.blumenstingl@googlemail.com, linux-hams@vger.kernel.org, Willem de Bruijn Subject: [PATCH net 2/3] packet: validate variable length ll headers Date: Fri, 4 Mar 2016 15:44:16 -0500 Message-Id: <1457124257-31486-3-git-send-email-willemdebruijn.kernel@gmail.com> X-Mailer: git-send-email 2.7.0.rc3.207.g0ac5344 In-Reply-To: <1457124257-31486-1-git-send-email-willemdebruijn.kernel@gmail.com> References: <1457124257-31486-1-git-send-email-willemdebruijn.kernel@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Willem de Bruijn Replace link layer header validation check ll_header_truncate with more generic dev_validate_header. Validation based on hard_header_len incorrectly drops valid packets in variable length protocols, such as AX25. dev_validate_header calls header_ops.validate for such protocols to ensure correctness below hard_header_len. See also http://comments.gmane.org/gmane.linux.network/401064 Signed-off-by: Willem de Bruijn --- net/packet/af_packet.c | 38 +++++++++++++++++--------------------- 1 file changed, 17 insertions(+), 21 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 992396a..488678a 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1916,6 +1916,10 @@ retry: goto retry; } + if (!dev_validate_header(dev, skb->data, len)) { + err = -EINVAL; + goto out_unlock; + } if (len > (dev->mtu + dev->hard_header_len + extra_len) && !packet_extra_vlan_len_allowed(dev, skb)) { err = -EMSGSIZE; @@ -2326,18 +2330,6 @@ static void tpacket_destruct_skb(struct sk_buff *skb) sock_wfree(skb); } -static bool ll_header_truncated(const struct net_device *dev, int len) -{ - /* net device doesn't like empty head */ - if (unlikely(len < dev->hard_header_len)) { - net_warn_ratelimited("%s: packet size is too short (%d < %d)\n", - current->comm, len, dev->hard_header_len); - return true; - } - - return false; -} - static void tpacket_set_protocol(const struct net_device *dev, struct sk_buff *skb) { @@ -2420,14 +2412,14 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, if (unlikely(err < 0)) return -EINVAL; } else if (dev->hard_header_len) { - if (ll_header_truncated(dev, tp_len)) - return -EINVAL; + int hhlen = min_t(int, dev->hard_header_len, tp_len); skb_push(skb, dev->hard_header_len); - err = skb_store_bits(skb, 0, data, - dev->hard_header_len); + err = skb_store_bits(skb, 0, data, hhlen); if (unlikely(err)) return err; + if (!dev_validate_header(dev, skb->data, hhlen)) + return -EINVAL; if (!skb->protocol) tpacket_set_protocol(dev, skb); @@ -2758,14 +2750,12 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) skb_set_network_header(skb, reserve); - err = -EINVAL; if (sock->type == SOCK_DGRAM) { offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); - if (unlikely(offset < 0)) - goto out_free; - } else { - if (ll_header_truncated(dev, len)) + if (unlikely(offset < 0)) { + err = -EINVAL; goto out_free; + } } /* Returns -EFAULT on error */ @@ -2773,6 +2763,12 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) if (err) goto out_free; + if (sock->type == SOCK_RAW && + !dev_validate_header(dev, skb->data, len)) { + err = -EINVAL; + goto out_free; + } + sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); if (!gso_type && (len > dev->mtu + reserve + extra_len) &&