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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 8A73DECDFBB for ; Fri, 20 Jul 2018 12:30:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A3AC20854 for ; Fri, 20 Jul 2018 12:30:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4A3AC20854 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387939AbeGTNSH (ORCPT ); Fri, 20 Jul 2018 09:18:07 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:37928 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728384AbeGTNSH (ORCPT ); Fri, 20 Jul 2018 09:18:07 -0400 Received: from localhost (LFbn-1-12238-233.w90-92.abo.wanadoo.fr [90.92.53.233]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 0D621BBD; Fri, 20 Jul 2018 12:29:33 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Floris Bos , Stefan Wahren , "David S. Miller" Subject: [PATCH 4.9 36/66] net: lan78xx: Fix race in tx pending skb size calculation Date: Fri, 20 Jul 2018 14:13:53 +0200 Message-Id: <20180720121409.339076517@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180720121407.228772286@linuxfoundation.org> References: <20180720121407.228772286@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefan Wahren commit dea39aca1d7aef1e2b95b07edeacf04cc8863a2e upstream. The skb size calculation in lan78xx_tx_bh is in race with the start_xmit, which could lead to rare kernel oopses. So protect the whole skb walk with a spin lock. As a benefit we can unlink the skb directly. This patch was tested on Raspberry Pi 3B+ Link: https://github.com/raspberrypi/linux/issues/2608 Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet") Cc: stable Signed-off-by: Floris Bos Signed-off-by: Stefan Wahren Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/lan78xx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -2964,6 +2964,7 @@ static void lan78xx_tx_bh(struct lan78xx pkt_cnt = 0; count = 0; length = 0; + spin_lock_irqsave(&tqp->lock, flags); for (skb = tqp->next; pkt_cnt < tqp->qlen; skb = skb->next) { if (skb_is_gso(skb)) { if (pkt_cnt) { @@ -2972,7 +2973,8 @@ static void lan78xx_tx_bh(struct lan78xx } count = 1; length = skb->len - TX_OVERHEAD; - skb2 = skb_dequeue(tqp); + __skb_unlink(skb, tqp); + spin_unlock_irqrestore(&tqp->lock, flags); goto gso_skb; } @@ -2981,6 +2983,7 @@ static void lan78xx_tx_bh(struct lan78xx skb_totallen = skb->len + roundup(skb_totallen, sizeof(u32)); pkt_cnt++; } + spin_unlock_irqrestore(&tqp->lock, flags); /* copy to a single skb */ skb = alloc_skb(skb_totallen, GFP_ATOMIC);