[dpdk-dev] [PATCH] net/vmxnet3: handle bad host framing

[Stephen Hemminger <stephen@networkplumber.org>]

The VMXNet3 protocol has a start-of-packet (SOP) and end-of-packet (EOP)
marker. If there was a bug where mbuf arrived without SOP the code
that chains the mbuf would dereference a null pointer.
Also, record any mbuf's dropped in statistics.

Although did the initial code no longer have access to VMware.
Compile tested only!

Coverity issue: 124563
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/net/vmxnet3/vmxnet3_rxtx.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/vmxnet3/vmxnet3_rxtx.c b/drivers/net/vmxnet3/vmxnet3_rxtx.c
index dd99684bee4d..73e270f30f00 100644
--- a/drivers/net/vmxnet3/vmxnet3_rxtx.c
+++ b/drivers/net/vmxnet3/vmxnet3_rxtx.c
@@ -950,13 +950,17 @@ vmxnet3_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 
 			RTE_ASSERT(rxd->btype == VMXNET3_RXD_BTYPE_BODY);
 
-			if (rxm->data_len) {
+			if (likely(start && rxm->data_len > 0)) {
 				start->pkt_len += rxm->data_len;
 				start->nb_segs++;
 
 				rxq->last_seg->next = rxm;
 				rxq->last_seg = rxm;
 			} else {
+				PMD_RX_LOG(ERR, "Error received empty or out of order frame.");
+				rxq->stats.drop_total++;
+				rxq->stats.drop_err++;
+
 				rte_pktmbuf_free_seg(rxm);
 			}
 		}
-- 
2.20.1