[PATCH 4.9 142/223] macsec: fix use-after-free of skb during RX

[Greg Kroah-Hartman]

From: Andreas Steinmetz <ast@xxxxxxxx>

[ Upstream commit 095c02da80a41cf6d311c504d8955d6d1c2add10 ]

Fix use-after-free of skb when rx_handler returns RX_HANDLER_PASS.

Signed-off-by: Andreas Steinmetz <ast@xxxxxxxx>
Acked-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/macsec.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -1105,10 +1105,9 @@ static rx_handler_result_t macsec_handle
 	}
 
 	skb = skb_unshare(skb, GFP_ATOMIC);
-	if (!skb) {
-		*pskb = NULL;
+	*pskb = skb;
+	if (!skb)
 		return RX_HANDLER_CONSUMED;
-	}
 
 	pulled_sci = pskb_may_pull(skb, macsec_extra_len(true));
 	if (!pulled_sci) {