From patchwork Tue Oct 27 13:51:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 306950 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 4D7EDC56201 for ; Tue, 27 Oct 2020 18:08:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0093F2076D for ; Tue, 27 Oct 2020 18:08:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603822084; bh=Gi9xAWMjEtClV20W/NLcZ676yflt9sTIaWwn+GeQ66g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0MvXtyguWUJ9Wd+0vx/m6n8Juyd+JqAD2VSVW+BQw1jhoZ3TDRHWt3nyQGi4GVhll yuqJOkJcPgLx0Rq/M2jlzwCEEH5JajlvVUnBYJqyBpzrmTTmx/Dk31q0Z7Wc7pBcpg hmUAfokHvuzES9Z0lgsWs8nc5+R5tf2RnGAuXaX8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1824765AbgJ0SFo (ORCPT ); Tue, 27 Oct 2020 14:05:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:40486 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2900902AbgJ0OR0 (ORCPT ); Tue, 27 Oct 2020 10:17:26 -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 B5D16206FA; Tue, 27 Oct 2020 14:17:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603808245; bh=Gi9xAWMjEtClV20W/NLcZ676yflt9sTIaWwn+GeQ66g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ztR4gZUgbL1qrASasUWPiaa0ksTyfpGdHF1ONsv/IJCFb6b95hscKxZvT+pSQsbOK abwZGWLIE1femdvK3BFh8TzBa589gdC1WPebKs/85O5deetbHU5ypYb815IawIDzlt eKes/leOS8CtQcyn6JO85RPmvrhIDIm0XJjGH5vU= 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 4.19 019/264] net: hdlc: In hdlc_rcv, check to make sure dev is an HDLC device Date: Tue, 27 Oct 2020 14:51:17 +0100 Message-Id: <20201027135431.570000754@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135430.632029009@linuxfoundation.org> References: <20201027135430.632029009@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -49,7 +49,15 @@ 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);