vhost: fix crash after mmap failure

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@dpdk.org
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 3ea64eb..5572134 100644 (file)
--- 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))
+               goto out_error;
+
        /* Find the region where the address lives. */
        for (i = 0; i < dev->mem->nregions; i++) {
                r = &dev->mem->regions[i];
@@ -503,6 +506,7 @@ qva_to_vva(struct virtio_net *dev, uint64_t qva, uint64_t *len)
                               r->host_user_addr;
                }
        }
+out_error:
        *len = 0;
 
        return 0;