Just realized that obj should be non-null. Small diff to fix this:

diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c

index 2cdea56..3e93893 100644

--- a/src/network/bridge_driver.c

+++ b/src/network/bridge_driver.c

@@ -3020,7 +3020,8 @@ networkGetDHCPLeases(virNetworkPtr network,

 

     virCheckFlags(0, -1);

 

-    obj = networkObjFromNetwork(network);

+    if (!(obj = networkObjFromNetwork(network)))

+        return rv;

 

     if (virNetworkGetDHCPLeasesEnsureACL(network->conn, obj->def) < 0)

         goto cleanup;

@@ -3044,7 +3045,8 @@ networkGetDHCPLeasesForMAC(virNetworkPtr network,

 

     virCheckFlags(0, -1);

 

-    obj = networkObjFromNetwork(network);

+    if (!(obj = networkObjFromNetwork(network)))

+        return rv;

 

     if (virNetworkGetDHCPLeasesForMACEnsureACL(network->conn, obj->def) < 0)

         goto cleanup;