From: Willem de Bruijn <willemb@xxxxxxxxxx>
[ Upstream commit 46e4c421a053c36bf7a33dda2272481bcaf3eed3 ]
In one error case, tpacket_rcv drops packets after incrementing the
ring producer index.
If this happens, it does not update tp_status to TP_STATUS_USER and
thus the reader is stalled for an iteration of the ring, causing out
of order arrival.
The only such error path is when virtio_net_hdr_from_skb fails due
to encountering an unknown GSO type.
Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/packet/af_packet.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2299,6 +2299,13 @@ static int tpacket_rcv(struct sk_buff *s
TP_STATUS_KERNEL, (macoff+snaplen));
if (!h.raw)
goto drop_n_account;
+
+ if (do_vnet &&
+ virtio_net_hdr_from_skb(skb, h.raw + macoff -
+ sizeof(struct virtio_net_hdr),
+ vio_le(), true, 0))
+ goto drop_n_account;
+
if (po->tp_version <= TPACKET_V2) {
packet_increment_rx_head(po, &po->rx_ring);
/*
@@ -2311,12 +2318,6 @@ static int tpacket_rcv(struct sk_buff *s
status |= TP_STATUS_LOSING;
}
- if (do_vnet &&
- virtio_net_hdr_from_skb(skb, h.raw + macoff -
- sizeof(struct virtio_net_hdr),
- vio_le(), true, 0))
- goto drop_n_account;
-
po->stats.stats1.tp_packets++;
if (copy_skb) {
status |= TP_STATUS_COPY;
