Currently, rx and tx functions for vhost interfaces always obtain
'vid' twice. First time inside 'is_vhost_running' for checking
the value and the second time in enqueue/dequeue function calls to
send/receive packets. But second time we're not checking the
returned value. If vhost device will be destroyed between
checking and enqueue/dequeue, DPDK API will be called with
'-1' instead of valid 'vid'. DPDK API does not validate the 'vid'.
This leads to getting random memory value as a pointer to internal
device structure inside DPDK. Access by this pointer leads to
segmentation fault. For example:
|00503|dpdk|INFO|VHOST_CONFIG: read message VHOST_USER_GET_VRING_BASE
[New Thread 0x7fb6754910 (LWP 21246)]
Program received signal SIGSEGV, Segmentation fault.
rte_vhost_enqueue_burst at lib/librte_vhost/virtio_net.c:630
630 if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
(gdb) bt full
#0 rte_vhost_enqueue_burst at lib/librte_vhost/virtio_net.c:630
dev = 0xffffffff
#1 __netdev_dpdk_vhost_send at lib/netdev-dpdk.c:1803
tx_pkts = <optimized out>
cur_pkts = 0x7f340084f0
total_pkts = 32
dropped = 0
i = <optimized out>
retries = 0
...
(gdb) p *((struct netdev_dpdk *) netdev)
$8 = { ... ,
flags = (NETDEV_UP | NETDEV_PROMISC), ... ,
vid = {v = -1},
vhost_reconfigured = false, ... }
Issue can be reproduced by stopping DPDK application (testpmd) inside
guest while heavy traffic flows to this VM.
Fix that by obtaining and checking the 'vid' only once.
CC: Ciara Loftus <[email protected]>
Fixes: 0a0f39df1d5a ("netdev-dpdk: Add support for DPDK 16.07")
Signed-off-by: Ilya Maximets <[email protected]>
---
lib/netdev-dpdk.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index c60f46f..bf30bb0 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -1637,18 +1637,18 @@ netdev_dpdk_vhost_rxq_recv(struct netdev_rxq *rxq,
struct dp_packet_batch *batch)
{
struct netdev_dpdk *dev = netdev_dpdk_cast(rxq->netdev);
- int qid = rxq->queue_id;
struct ingress_policer *policer = netdev_dpdk_get_ingress_policer(dev);
uint16_t nb_rx = 0;
uint16_t dropped = 0;
+ int qid = rxq->queue_id;
+ int vid = netdev_dpdk_get_vid(dev);
- if (OVS_UNLIKELY(!is_vhost_running(dev)
+ if (OVS_UNLIKELY(vid < 0 || !dev->vhost_reconfigured
|| !(dev->flags & NETDEV_UP))) {
return EAGAIN;
}
- nb_rx = rte_vhost_dequeue_burst(netdev_dpdk_get_vid(dev),
- qid * VIRTIO_QNUM + VIRTIO_TXQ,
+ nb_rx = rte_vhost_dequeue_burst(vid, qid * VIRTIO_QNUM + VIRTIO_TXQ,
dev->dpdk_mp->mp,
(struct rte_mbuf **) batch->packets,
NETDEV_MAX_BURST);
@@ -1783,10 +1783,11 @@ __netdev_dpdk_vhost_send(struct netdev *netdev, int qid,
unsigned int total_pkts = cnt;
unsigned int dropped = 0;
int i, retries = 0;
+ int vid = netdev_dpdk_get_vid(dev);
qid = dev->tx_q[qid % netdev->n_txq].map;
- if (OVS_UNLIKELY(!is_vhost_running(dev) || qid < 0
+ if (OVS_UNLIKELY(vid < 0 || !dev->vhost_reconfigured || qid < 0
|| !(dev->flags & NETDEV_UP))) {
rte_spinlock_lock(&dev->stats_lock);
dev->stats.tx_dropped+= cnt;
@@ -1805,8 +1806,7 @@ __netdev_dpdk_vhost_send(struct netdev *netdev, int qid,
int vhost_qid = qid * VIRTIO_QNUM + VIRTIO_RXQ;
unsigned int tx_pkts;
- tx_pkts = rte_vhost_enqueue_burst(netdev_dpdk_get_vid(dev),
- vhost_qid, cur_pkts, cnt);
+ tx_pkts = rte_vhost_enqueue_burst(vid, vhost_qid, cur_pkts, cnt);
if (OVS_LIKELY(tx_pkts)) {
/* Packets have been sent.*/
cnt -= tx_pkts;
--
2.7.4
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