From patchwork Mon Oct 5 15:26:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 290671 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=-10.5 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 2C770C4363D for ; Mon, 5 Oct 2020 15:28:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBBDB20E65 for ; Mon, 5 Oct 2020 15:28:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601911697; bh=j4oVaPjWeJ+MXFCZagiH8DF+SGIz1nEB5A0wWdeWGdI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ojo8zIii9DXQRWyCcfYOBTCSDIrQAegnnLZgQ5bQhftSlLGKl2NeKoMaU+Nwt8AVt FSGKIsA2YzPuJLJZvErUO7DEbZOWmUzx9ykdC+zZ64RwNLuVzwVMWftNaKLx7Mf8W/ FGnLA4/ZIb/uWILj5Zh56x1shCbvZShO3x8lhSB4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727342AbgJEP2J (ORCPT ); Mon, 5 Oct 2020 11:28:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:52694 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727260AbgJEP15 (ORCPT ); Mon, 5 Oct 2020 11:27:57 -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 AE97420B80; Mon, 5 Oct 2020 15:27:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601911675; bh=j4oVaPjWeJ+MXFCZagiH8DF+SGIz1nEB5A0wWdeWGdI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w+OFwt0bAJKG6FABs8JJ3F2XAERlZnsCiL/BXrZk95MHQ2Civ20uMxbCXCkJjUmKe ZgbKD1b4oqWxAfKO8YF6lsVtdzf/0zazqvxTWYlY8vItMx71mm7xaoAybIEKJjwQjd fPK0w58Rw1wg5wEbU2JEtHa9mVYaK/HRpkOqO0vk= 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 4.19 33/38] net/packet: fix overflow in tpacket_rcv Date: Mon, 5 Oct 2020 17:26:50 +0200 Message-Id: <20201005142110.273161307@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201005142108.650363140@linuxfoundation.org> References: <20201005142108.650363140@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -2162,7 +2162,8 @@ 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; @@ -2225,6 +2226,12 @@ 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 &&