[PATCH net-next 04/12] tap: fix use-after-free

[Michael S. Tsirkin]

Lockless access to __ptr_ring_full is only legal if ring is
never resized, otherwise it might cause use-after free errors.
Simply drop the lockless test, we'll drop the packet
a bit later when produce fails.

Fixes: 362899b8 ("macvtap: switch to use skb array")
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
 drivers/net/tap.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index 7c38659..7787269 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -330,9 +330,6 @@ rx_handler_result_t tap_handle_frame(struct sk_buff **pskb)
 	if (!q)
 		return RX_HANDLER_PASS;
 
-	if (__ptr_ring_full(&q->ring))
-		goto drop;
-
 	skb_push(skb, ETH_HLEN);
 
 	/* Apply the forward feature mask so that we perform segmentation
-- 
MST