From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1874556-1527162381-2-11591795517110181126 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1527162380; b=YmSL3Oi7x/xEuiP95aRkGX/9okHw91OnNzyDA100wNaSOtHVx+ YtXcIRDJDXVk60PjxvxRJAM8KLOLWibaaR14qCk3KPJkee8PUVbMD0yG3I495so9 lbmwzsivvAyZsJKAz6ZxfjXbk0Cnhf0s1DDC2is90yewrHOONF5fgMfeWsHFvW/i lX5KaytgGjv4k4E33cZxgXZQjwFAOTlI/CgtTOcAtfaDRv7RRJ861NQteP6nE3TU a2jCSzqiVg1TgVHt6fp+4YlGCmdFxtKO7ZjaVaTlujwRiiX0ss2W3JZWStXqipa2 5NCrn9E9yo+C8cX/c5tco3PEu34vFkFCOmzQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=fm2; t=1527162380; bh=hrGxuQnlmOPUiZN3oM5vVjN7LT1BFy BqiGHtmidAWTA=; b=RW6kWcnV4vX8rFqozDHeD+K/Gzl9ZCNxqMSC0Nqrv58VPk tgWQ3MA8fnstJ51oWOycGzc4KPdTpTXlzkXat3rrKglBNk67xel5AUxy/otmE62k ei5Rsn9xMEu1Wrg6FC6oAhFhc5oW7rhYdTHlqSWo1URT9RMt38mnXgDkjvECPbEC Ung7jORQ5uv3VM9kTpwYre3ezLeuedgq4jS22Px7zPDAe/oH6g4BKH8fHZEdao6J +pY/KSkjw6B0qm9rWeCSRWHtYJZmna6l8mT0ufIclN0lRlGQtVqnIOJBv6HYx80A rYH5oWKXy/ReCLPsH6SLtA/veKwY6CdiTykCBOkQ== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=kernel.org header.i=@kernel.org header.b=QUPlclp7 x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=default; dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=kernel.org header.i=@kernel.org header.b=QUPlclp7 x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=default; dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfIdHQvY9avlIxbt4p+pgR/myR9uLyVNLHQEwrwb3hxaA3C9QWrpryIOB1QBVVx/zeVTXNNHzMyePB9WTDB3GyBW8q8+gs86gI8Jo5JfXBynBvMktdtw3 +ISiwyCx7BN1VkaAtFG3v7l4dfpabMS4RG4Bezgn4kwDHTq/zsn3aS0kR9r8uFVrf9aJLGlMzFQxse0m2DxlzdBvR3pb9Fq5uteKaZNliAux4F7bXmjK2ziR X-CM-Analysis: v=2.3 cv=WaUilXpX c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=IkcTkHD0fZMA:10 a=VUJBJC2UJ8kA:10 a=1XWaLZrsAAAA:8 a=hSkVLCK3AAAA:8 a=J1Y8HTJGAAAA:8 a=ag1SF4gXAAAA:8 a=G8Vht56IOoz3jrsCRGQA:9 a=9MzY4qaIEuA2mC1_:21 a=ise_7HGtSiYG6tJr:21 a=QEXdDO2ut3YA:10 a=cQPPKAXgyycSBL8etih5:22 a=y1Q9-5lHfBjTkpIzbSAN:22 a=Yupwre4RP9_Eg_Bd0iYG:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967115AbeEXJrt (ORCPT ); Thu, 24 May 2018 05:47:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:60666 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967106AbeEXJrr (ORCPT ); Thu, 24 May 2018 05:47:47 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+71d74a5406d02057d559@syzkaller.appspotmail.com, Willem de Bruijn , "David S. Miller" Subject: [PATCH 4.9 03/96] packet: in packet_snd start writing at link layer allocation Date: Thu, 24 May 2018 11:37:46 +0200 Message-Id: <20180524093605.846607760@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180524093605.602125311@linuxfoundation.org> References: <20180524093605.602125311@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Willem de Bruijn [ Upstream commit b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba ] Packet sockets allow construction of packets shorter than dev->hard_header_len to accommodate protocols with variable length link layer headers. These packets are padded to dev->hard_header_len, because some device drivers interpret that as a minimum packet size. packet_snd reserves dev->hard_header_len bytes on allocation. SOCK_DGRAM sockets call skb_push in dev_hard_header() to ensure that link layer headers are stored in the reserved range. SOCK_RAW sockets do the same in tpacket_snd, but not in packet_snd. Syzbot was able to send a zero byte packet to a device with massive 116B link layer header, causing padding to cross over into skb_shinfo. Fix this by writing from the start of the llheader reserved range also in the case of packet_snd/SOCK_RAW. Update skb_set_network_header to the new offset. This also corrects it for SOCK_DGRAM, where it incorrectly double counted reserve due to the skb_push in dev_hard_header. Fixes: 9ed988cd5915 ("packet: validate variable length ll headers") Reported-by: syzbot+71d74a5406d02057d559@syzkaller.appspotmail.com Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/packet/af_packet.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2910,13 +2910,15 @@ static int packet_snd(struct socket *soc if (skb == NULL) goto out_unlock; - skb_set_network_header(skb, reserve); + skb_reset_network_header(skb); 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 (reserve) { + skb_push(skb, reserve); } /* Returns -EFAULT on error */