[Patch net] igb: pass the correct maxlen for eth_get_headlen()

[Cong Wang <xiyou.wangcong@gmail.com>]

The second parameter of eth_get_headlen() is the length of
the frame buffer, not the header length of skb.

Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index a0a9b1f..7b3a370 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -6852,7 +6852,9 @@ static void igb_pull_tail(struct igb_ring *rx_ring,
 	/* we need the header to contain the greater of either ETH_HLEN or
 	 * 60 bytes if the skb->len is less than 60 for skb_pad.
 	 */
-	pull_len = eth_get_headlen(va, IGB_RX_HDR_LEN);
+	pull_len = eth_get_headlen(va, skb_frag_size(frag));
+	if (unlikely(pull_len > IGB_RX_HDR_LEN))
+		pull_len = IGB_RX_HDR_LEN;
 
 	/* align pull length to size of long to optimize memcpy performance */
 	skb_copy_to_linear_data(skb, va, ALIGN(pull_len, sizeof(long)));
-- 
1.8.3.1