tap: fix use-after-free

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michael S. Tsirkin 2018-01-26 01:36:31 +02:00 committed by David S. Miller
parent a259df36d1
commit 88fae87327

View File

@ -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