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 1C986C63697 for ; Tue, 27 Oct 2020 17:25:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A985221D42 for ; Tue, 27 Oct 2020 17:25:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603819548; bh=hMMjolOHhezTfEboHVT4V0QWkMrOOg2PC5xiFDOy9FI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tiwSmbn3jk3mIBKW2n9MJSj60M3NRExcnNpvNaFR2Hyb0y7WgTJRNoU8ULN4g7/4g wWkthS14SgZtyN2WkDbkE+kH8ENK7TA8sNAyJrIn/txb3lUBAg4xmrUx3VrecHoULa a6hMBR2Zn+vZWEAiWLog/J5lRuEvJ+x7zHDofd2I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1766330AbgJ0Ox1 (ORCPT ); Tue, 27 Oct 2020 10:53:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:49802 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1768387AbgJ0Otm (ORCPT ); Tue, 27 Oct 2020 10:49:42 -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 22F39206E5; Tue, 27 Oct 2020 14:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603810181; bh=hMMjolOHhezTfEboHVT4V0QWkMrOOg2PC5xiFDOy9FI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fLLoORzFXFRnMKxd9VQoYN6lFTW3eMqfmDU4h8db/WmdSDjSYsGXJqoz0wr7UIhPK HMZuUsore8VlDzeBTLVl4IhH1CD9YBo9+aZEMECbDj0Ha8h/ra9ZxU3eFnlM86uPkx +2KCCr17gMLRzoOYTHiUJyRp75gPKOQCLwDiu9Ss= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Krzysztof Halasa , Xie He , Jakub Kicinski Subject: [PATCH 5.8 042/633] net: hdlc: In hdlc_rcv, check to make sure dev is an HDLC device Date: Tue, 27 Oct 2020 14:46:25 +0100 Message-Id: <20201027135524.677380618@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135522.655719020@linuxfoundation.org> References: <20201027135522.655719020@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: Xie He [ Upstream commit 01c4ceae0a38a0bdbfea6896f41efcd985a9c064 ] The hdlc_rcv function is used as hdlc_packet_type.func to process any skb received in the kernel with skb->protocol == htons(ETH_P_HDLC). The purpose of this function is to provide second-stage processing for skbs not assigned a "real" L3 skb->protocol value in the first stage. This function assumes the device from which the skb is received is an HDLC device (a device created by this module). It assumes that netdev_priv(dev) returns a pointer to "struct hdlc_device". However, it is possible that some driver in the kernel (not necessarily in our control) submits a received skb with skb->protocol == htons(ETH_P_HDLC), from a non-HDLC device. In this case, the skb would still be received by hdlc_rcv. This will cause problems. hdlc_rcv should be able to recognize and drop invalid skbs. It should first make sure "dev" is actually an HDLC device, before starting its processing. This patch adds this check to hdlc_rcv. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: Krzysztof Halasa Signed-off-by: Xie He Link: https://lore.kernel.org/r/20201020013152.89259-1-xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/wan/hdlc.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/net/wan/hdlc.c +++ b/drivers/net/wan/hdlc.c @@ -46,7 +46,15 @@ static struct hdlc_proto *first_proto; static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *p, struct net_device *orig_dev) { - struct hdlc_device *hdlc = dev_to_hdlc(dev); + struct hdlc_device *hdlc; + + /* First make sure "dev" is an HDLC device */ + if (!(dev->priv_flags & IFF_WAN_HDLC)) { + kfree_skb(skb); + return NET_RX_SUCCESS; + } + + hdlc = dev_to_hdlc(dev); if (!net_eq(dev_net(dev), &init_net)) { kfree_skb(skb);