From 46e4c421a053c36bf7a33dda2272481bcaf3eed3 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 9 Mar 2020 11:34:35 -0400 Subject: net/packet: tpacket_rcv: do not increment ring index on drop 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 Signed-off-by: David S. Miller --- net/packet/af_packet.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'net/packet') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 30c6879d6774..e5b0986215d2 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2274,6 +2274,13 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 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); /* @@ -2286,12 +2293,6 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 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; -- cgit v1.2.3