Avoid shutdown-time crash in wpa_supplicant.

src/tspi/rpc/hosttable.c

 
 /*
  * Licensed Materials - Property of IBM
  *
  * trousers - An open source TCG Software Stack
  *
  * (C) Copyright International Business Machines Corp. 2004
  *
  */
 
@@ skipping 140 matching lines @@
         }
 
         MUTEX_UNLOCK(ht->lock);
 }
 
 struct host_table_entry *
 get_table_entry(TSS_HCONTEXT tspContext)
 {
         struct host_table_entry *index = NULL;
 
+        /* Avoid shutdown race in wpa_supplicant */
+        if (ht == NULL)
+                return NULL;
+
         MUTEX_LOCK(ht->lock);
 
         for (index = ht->entries; index; index = index->next) {
                 if (index->tspContext == tspContext)
                         break;
         }
 
         if (index)
                 MUTEX_LOCK(index->lock);
 
         MUTEX_UNLOCK(ht->lock);
 
         return index;
 }
 
 void
 put_table_entry(struct host_table_entry *entry)
 {
         if (entry)
                 MUTEX_UNLOCK(entry->lock);
 }
-