4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Juergen Gross <jgross@xxxxxxxx>
commit d472b3a6cf63cd31cae1ed61930f07e6cd6671b5 upstream.
skb_shinfo() can change when calling __pskb_pull_tail(): Don't cache
its return value.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -879,7 +879,6 @@ 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;
@@ -888,15 +887,16 @@ 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;
