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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 71CA6C433E7 for ; Mon, 12 Oct 2020 13:35:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 259E2221FC for ; Mon, 12 Oct 2020 13:35:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602509711; bh=z3+prIcdo/jLC3VpEESws0UfaJtKsVE6ehu/FanrpjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iwYf4lKn03eVP0qQ7zv4NkuDWYBPWyptb6rHkigAxEjdhnHHr7EwsUK+9HfMjB6GM vtu22txVtMSjQdMuw3YBqwR54qxzBc3HelMLd2cH+1iYrDodDK2seSNMI2tnZfBa8d G6Oitf9iHLsjc1K8zl2bSrOJ3E3Y+JBkGs3yyuZw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730348AbgJLNfJ (ORCPT ); Mon, 12 Oct 2020 09:35:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:36966 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730260AbgJLNeb (ORCPT ); Mon, 12 Oct 2020 09:34:31 -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 019D420678; Mon, 12 Oct 2020 13:34:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602509670; bh=z3+prIcdo/jLC3VpEESws0UfaJtKsVE6ehu/FanrpjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MFYZffnbPXv1kavoyxBOBTmDLS1P9Xgv7HSuOUwJ0U+mZM76BLNG0iP4Dh4cfazas ZK6ouPXrvcmy5aiFG5kzb06rdgj8Igduf0+soWA+K3eg82YxNjOXkdGPcl/cdkLrgf p1RQ82AzU95zbQr1rLCt8AjXr8V7MCj8GGP8u2EE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Or Cohen , Eric Dumazet , Linus Torvalds , Stefan Nuernberger , David Woodhouse , Amit Shah Subject: [PATCH 4.9 17/54] net/packet: fix overflow in tpacket_rcv Date: Mon, 12 Oct 2020 15:26:39 +0200 Message-Id: <20201012132630.392196471@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012132629.585664421@linuxfoundation.org> References: <20201012132629.585664421@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Or Cohen commit acf69c946233259ab4d64f8869d4037a198c7f06 upstream. 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 [ snu: backported to pre-5.3, changed tp_drops counting/locking ] Signed-off-by: Stefan Nuernberger CC: David Woodhouse CC: Amit Shah CC: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- net/packet/af_packet.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2161,7 +2161,8 @@ static int tpacket_rcv(struct sk_buff *s 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; @@ -2223,6 +2224,12 @@ static int tpacket_rcv(struct sk_buff *s } macoff = netoff - maclen; } + if (netoff > USHRT_MAX) { + spin_lock(&sk->sk_receive_queue.lock); + po->stats.stats1.tp_drops++; + spin_unlock(&sk->sk_receive_queue.lock); + goto drop_n_restore; + } if (po->tp_version <= TPACKET_V2) { if (macoff + snaplen > po->rx_ring.frame_size) { if (po->copy_thresh &&