From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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: Subject: [PATCH 3.16 321/366] xen/netfront: don't cache skb_shinfo() In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 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;