4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Juergen Gross <jgross@xxxxxxxx>
[ Upstream commit d81c5054a5d1d4999c7cdead7636b6cd4af83d36 ]
At least old Xen net backends seem to send frags with no real data
sometimes. In case such a fragment happens to occur with the frag limit
already reached the frontend will BUG currently even if this situation
is easily recoverable.
Modify the BUG_ON() condition accordingly.
Tested-by: Dietmar Hahn <dietmar.hahn@xxxxxxxxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/xen-netfront.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -903,7 +903,7 @@ static RING_IDX xennet_fill_frags(struct
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));
+ BUG_ON(pull_to < skb_headlen(skb));
__pskb_pull_tail(skb, pull_to - skb_headlen(skb));
}
if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
