[PATCH net 4/4] virito-net: fix leaking page for gso packet during mergeable XDP

Jason Wang
2018-05-21T08:35:32Z

We need to drop refcnt to xdp_page if we see a gso packet. Otherwise
it will be leaked. Fixing this by moving the check of gso packet above
the linearizing logic.

Cc: John Fastabend <john.fastabend@gmail.com>
Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 165a922..f8db809 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -707,6 +707,14 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
void *data;
u32 act;

+ /* Transient failure which in theory could occur if
+ * in-flight packets from before XDP was enabled reach
+ * the receive path after XDP is loaded. In practice I
+ * was not able to create this condition.
+ */
+ if (unlikely(hdr->hdr.gso_type))
+ goto err_xdp;
+
/* This happens when rx buffer size is underestimated
* or headroom is not enough because of the buffer
* was refilled before XDP is set. This should only
@@ -728,14 +736,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
xdp_page = page;
}

- /* Transient failure which in theory could occur if
- * in-flight packets from before XDP was enabled reach
- * the receive path after XDP is loaded. In practice I
- * was not able to create this condition.
- */
- if (unlikely(hdr->hdr.gso_type))
- goto err_xdp;
-
/* Allow consuming headroom but reserve enough space to push
* the descriptor on if we get an XDP_TX return code.
*/
--
2.7.4