ovn-nbd: Fix unsafe HMAP_FOR_EACH_WITH_HASH usage.

The previous code assumed that hash_node would be NULL when the loop
terminated without a match.  That's not the case, so track the match a
little differently.

Signed-off-by: Russell Bryant <rbryant@redhat.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/ovn/ovn-nbd.c b/ovn/ovn-nbd.c
index 1571a0b56..27e90c60d 100644
--- a/ovn/ovn-nbd.c
+++ b/ovn/ovn-nbd.c
@@ -152,19 +152,20 @@ set_bindings(struct nbd_context *ctx)
     }
 
     NBREC_LOGICAL_PORT_FOR_EACH(lport, ctx->ovnnb_idl) {
+        binding = NULL;
         HMAP_FOR_EACH_WITH_HASH(hash_node, node,
                 hash_string(lport->name, 0), &bindings_hmap) {
             if (!strcmp(lport->name, hash_node->binding->logical_port)) {
+                binding = hash_node->binding;
                 break;
             }
         }
 
-        if (hash_node) {
+        if (binding) {
             /* We found an existing binding for this logical port.  Update its
              * contents.  Right now the only thing we expect that could change
              * is the list of MAC addresses. */
 
-            binding = hash_node->binding;
             hmap_remove(&bindings_hmap, &hash_node->node);
             free(hash_node);
             hash_node = NULL;