[dpdk-stable] [PATCH] vhost: fix possible null pointer dereferencing

[Maxime Coquelin]

If mmap() call fails in vhost_user_set_mem_table, dev->mem
is set to NULL. If later, qva_to_vva() is called, a segfault
occurs.

Fixes: 8f972312b8f4 ("vhost: support vhost-user")
Cc: stable at dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 lib/librte_vhost/vhost_user.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 3ea64eba6..c44fef9cc 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -489,6 +489,9 @@ qva_to_vva(struct virtio_net *dev, uint64_t qva, uint64_t *len)
 	struct rte_vhost_mem_region *r;
 	uint32_t i;
 
+	if (unlikely(!dev || !dev->mem))
+		return 0;
+
 	/* Find the region where the address lives. */
 	for (i = 0; i < dev->mem->nregions; i++) {
 		r = &dev->mem->regions[i];
-- 
2.17.2