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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 31216C43441 for ; Sun, 11 Nov 2018 20:33:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E73AA20818 for ; Sun, 11 Nov 2018 20:33:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E73AA20818 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk 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 S1730889AbeKLGWo (ORCPT ); Mon, 12 Nov 2018 01:22:44 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50154 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730175AbeKLFsQ (ORCPT ); Mon, 12 Nov 2018 00:48:16 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvsc-0000lF-1K; Sun, 11 Nov 2018 19:58:46 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsZ-0001pv-Fc; Sun, 11 Nov 2018 19:58:43 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Wei Liu" , "Juergen Gross" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 321/366] xen/netfront: don't cache skb_shinfo() In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Juergen Gross commit d472b3a6cf63cd31cae1ed61930f07e6cd6671b5 upstream. skb_shinfo() can change when calling __pskb_pull_tail(): Don't cache its return value. Signed-off-by: Juergen Gross Reviewed-by: Wei Liu Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- drivers/net/xen-netfront.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -898,7 +898,6 @@ static RING_IDX xennet_fill_frags(struct struct sk_buff *skb, struct sk_buff_head *list) { - struct skb_shared_info *shinfo = skb_shinfo(skb); RING_IDX cons = queue->rx.rsp_cons; struct sk_buff *nskb; @@ -907,15 +906,16 @@ static RING_IDX xennet_fill_frags(struct RING_GET_RESPONSE(&queue->rx, ++cons); skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; - if (shinfo->nr_frags == MAX_SKB_FRAGS) { + if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) { unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; BUG_ON(pull_to <= skb_headlen(skb)); __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); } - BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS); + BUG_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS); - skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag), + skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, + skb_frag_page(nfrag), rx->offset, rx->status, PAGE_SIZE); skb_shinfo(nskb)->nr_frags = 0;