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.

Cc: stable@vger.kernel.org Tested-by: Dietmar Hahn dietmar.hahn@ts.fujitsu.com Signed-off-by: Juergen Gross jgross@suse.com --- drivers/net/xen-netfront.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index f17f602e6171..5b97cc946d70 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -905,7 +905,7 @@ static RING_IDX xennet_fill_frags(struct netfront_queue *queue, 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)) {