[dpdk-stable] [PATCH v2] examples/vhost: fix use-after-free on drain vhost

[Wenwu Ma]

When a vdev is removed in destroy_device function,
the corresponding vhost TX buffer will also be freed,
but the vhost TX buffer may still be used in the
drain_vhost function, which will cause an error of
heap-use-after-free. Therefore, before accessing
vhost TX buffer, we need to check whether the vdev
has been removed, if so, let's skip this vdev.

Fixes: a68ba8e0a6b6 ("examples/vhost: refactor vhost data path")
Cc: stable at dpdk.org

Signed-off-by: Wenwu Ma <wenwux.ma at intel.com>
---
 examples/vhost/main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index d0bf1f31e3..1f6f7be8e3 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -916,6 +916,9 @@ drain_vhost_table(void)
 	uint64_t cur_tsc;
 
 	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
+		if (unlikely(vdev->remove == 1))
+			continue;
+
 		vhost_txq = vhost_txbuff[lcore_id * MAX_VHOST_DEVICE
 						+ vdev->vid];
 
-- 
2.25.1