[dpdk-dev] [PATCH v2] net/af_packet: fix vlan_insert corruption

[Stephen Hemminger]

If the af_packet transmit is sending a VLAN packet,
and the transmit path to the kernel os full, then it would
mismanage the outgoing mbuf. The original mbuf would end up
being freed twice, once by AF_PACKET PMD and once by caller.

Reported-by: Chas Williams <3chas3 at gmail.com>
Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
v2 - fix unnecessary parenthesis (was in original code)

 drivers/net/af_packet/rte_eth_af_packet.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/af_packet/rte_eth_af_packet.c b/drivers/net/af_packet/rte_eth_af_packet.c
index 99e13fe48a30..91ceb94ecbaa 100644
--- a/drivers/net/af_packet/rte_eth_af_packet.c
+++ b/drivers/net/af_packet/rte_eth_af_packet.c
@@ -200,6 +200,11 @@ eth_af_packet_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 			continue;
 		}
 
+		/* point at the next incoming frame */
+		if (ppd->tp_status != TP_STATUS_AVAILABLE &&
+		    poll(&pfd, 1, -1) < 0)
+			break;
+
 		/* insert vlan info if necessary */
 		if (mbuf->ol_flags & PKT_TX_VLAN_PKT) {
 			if (rte_vlan_insert(&mbuf)) {
@@ -208,11 +213,6 @@ eth_af_packet_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 			}
 		}
 
-		/* point at the next incoming frame */
-		if ((ppd->tp_status != TP_STATUS_AVAILABLE) &&
-		    (poll(&pfd, 1, -1) < 0))
-			break;
-
 		/* copy the tx frame data */
 		pbuf = (uint8_t *) ppd + TPACKET2_HDRLEN -
 			sizeof(struct sockaddr_ll);
-- 
2.17.1