[PATCH 4.2.y-ckt 038/305] ipvlan: fix use after free of skb

[Kamal Mostafa]

4.2.8-ckt2 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Sabrina Dubroca <sd at queasysnail.net>

commit a534dc529853c69e94994aa47c1d80a03ce2c11d upstream.

ipvlan_handle_frame is a rx_handler, and when it returns a value other
than RX_HANDLER_CONSUMED (here, NET_RX_DROP aka RX_HANDLER_ANOTHER),
__netif_receive_skb_core expects that the skb still exists and will
process it further, but we just freed it.

Fixes: 2ad7bf363841 ("ipvlan: Initial check-in of the IPVLAN driver.")
Signed-off-by: Sabrina Dubroca <sd at queasysnail.net>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/ipvlan/ipvlan_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index a50a942..b64e172 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -651,5 +651,5 @@ rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
 	WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
 			  port->mode);
 	kfree_skb(skb);
-	return NET_RX_DROP;
+	return RX_HANDLER_CONSUMED;
 }
-- 
1.9.1