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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 176C5C43461 for ; Tue, 8 Sep 2020 17:27:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B51B62078B for ; Tue, 8 Sep 2020 17:27:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599586053; bh=7Pzg1WVdz2wq0y7jIJVV0/6t7pgXAjx9arQklN+Os+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uvvsKP1JRdnqessN//I6CQ179p8HcccSri5qjaQHI0p0CryarlBrXZdE1khnPLIXj 2AxxTy/64WdLPvWkzlAQU2eYZdd1lGnnlSegoMQvmErvOPTREdm5m0l/VF0iW8GvnB 5cFHiMt1k+Gsgs5ZdzVkFLBzmRmkkO4BrhG3tX0Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731873AbgIHR1c (ORCPT ); Tue, 8 Sep 2020 13:27:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:58436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731510AbgIHQQ5 (ORCPT ); Tue, 8 Sep 2020 12:16:57 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 68FA42482B; Tue, 8 Sep 2020 15:44:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599579883; bh=7Pzg1WVdz2wq0y7jIJVV0/6t7pgXAjx9arQklN+Os+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oE1EC1P3+K7cfPl2h8QxzDOiiK2rK9jgpr6F7NySnZI9Yg2/Gy01um/i75EwXU+hV Q72BVwpllqsO0DhnQ3tFb1Ql2IBpqEaDPomS7QiIoTJ64YFvHC0zapzF8mgcBfnTwn AQjCfpMq85+f19FSKJiGnsWPFC28re7bZzzqK5Os= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Or Cohen , Eric Dumazet , Linus Torvalds , Sasha Levin Subject: [PATCH 5.4 071/129] net/packet: fix overflow in tpacket_rcv Date: Tue, 8 Sep 2020 17:25:12 +0200 Message-Id: <20200908152233.248148317@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908152229.689878733@linuxfoundation.org> References: <20200908152229.689878733@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: Or Cohen [ Upstream commit acf69c946233259ab4d64f8869d4037a198c7f06 ] Using tp_reserve to calculate netoff can overflow as tp_reserve is unsigned int and netoff is unsigned short. This may lead to macoff receving a smaller value then sizeof(struct virtio_net_hdr), and if po->has_vnet_hdr is set, an out-of-bounds write will occur when calling virtio_net_hdr_from_skb. The bug is fixed by converting netoff to unsigned int and checking if it exceeds USHRT_MAX. This addresses CVE-2020-14386 Fixes: 8913336a7e8d ("packet: add PACKET_RESERVE sockopt") Signed-off-by: Or Cohen Signed-off-by: Eric Dumazet Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 7735340c892eb..fbc2d4dfddf0e 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2169,7 +2169,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, int skb_len = skb->len; unsigned int snaplen, res; unsigned long status = TP_STATUS_USER; - unsigned short macoff, netoff, hdrlen; + unsigned short macoff, hdrlen; + unsigned int netoff; struct sk_buff *copy_skb = NULL; struct timespec ts; __u32 ts_status; @@ -2238,6 +2239,10 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, } macoff = netoff - maclen; } + if (netoff > USHRT_MAX) { + atomic_inc(&po->tp_drops); + goto drop_n_restore; + } if (po->tp_version <= TPACKET_V2) { if (macoff + snaplen > po->rx_ring.frame_size) { if (po->copy_thresh && -- 2.25.1