Actually finish memcache_add_talloc

This fixes a memleak found by Martin Zielinski <mz@seh.de>. Thanks for
looking closely!

Volker
(cherry picked from commit a31a84a078100819809e6d40dbc3df207a50a0b2)

2 files changed, 68 insertions, 2 deletions

diff --git a/source3/lib/memcache.c b/source3/lib/memcache.c
index d586f707fa..1951b4abf9 100644
--- a/source3/lib/memcache.c
+++ b/source3/lib/memcache.c
@@ -40,6 +40,24 @@ struct memcache {
 static void memcache_element_parse(struct memcache_element *e,
 				   DATA_BLOB *key, DATA_BLOB *value);
 
+static bool memcache_is_talloc(enum memcache_number n)
+{
+	bool result;
+
+	switch (n) {
+	case GETPWNAM_CACHE:
+	case PDB_GETPWSID_CACHE:
+	case SINGLETON_CACHE_TALLOC:
+		result = true;
+		break;
+	default:
+		result = false;
+		break;
+	}
+
+	return result;
+}
+
 static int memcache_destructor(struct memcache *cache) {
 	struct memcache_element *e, *next;
 
@@ -188,6 +206,16 @@ static void memcache_delete_element(struct memcache *cache,
 	}
 	DLIST_REMOVE(cache->mru, e);
 
+	if (memcache_is_talloc(e->n)) {
+		DATA_BLOB cache_key, cache_value;
+		void *ptr;
+
+		memcache_element_parse(e, &cache_key, &cache_value);
+		SMB_ASSERT(cache_value.length == sizeof(ptr));
+		memcpy(&ptr, cache_value.data, sizeof(ptr));
+		TALLOC_FREE(ptr);
+	}
+
 	cache->size -= memcache_element_size(e->keylength, e->valuelength);
 
 	SAFE_FREE(e);
@@ -250,6 +278,12 @@ void memcache_add(struct memcache *cache, enum memcache_number n,
 		memcache_element_parse(e, &cache_key, &cache_value);
 
 		if (value.length <= cache_value.length) {
+			if (memcache_is_talloc(e->n)) {
+				void *ptr;
+				SMB_ASSERT(cache_value.length == sizeof(ptr));
+				memcpy(&ptr, cache_value.data, sizeof(ptr));
+				TALLOC_FREE(ptr);
+			}
 			/*
 			 * We can reuse the existing record
 			 */
@@ -308,7 +342,8 @@ void memcache_add(struct memcache *cache, enum memcache_number n,
 void memcache_add_talloc(struct memcache *cache, enum memcache_number n,
 			 DATA_BLOB key, void *ptr)
 {
-	memcache_add(cache, n, key, data_blob_const(&ptr, sizeof(ptr)));
+	void *p = talloc_move(cache, &ptr);
+	memcache_add(cache, n, key, data_blob_const(&p, sizeof(p)));
 }
 
 void memcache_flush(struct memcache *cache, enum memcache_number n)
diff --git a/source3/torture/torture.c b/source3/torture/torture.c
index 904fb5c262..762ea214d1 100644
--- a/source3/torture/torture.c
+++ b/source3/torture/torture.c
@@ -5291,6 +5291,11 @@ static bool run_local_memcache(int dummy)
 	DATA_BLOB d1, d2, d3;
 	DATA_BLOB v1, v2, v3;
 
+	TALLOC_CTX *mem_ctx;
+	char *str1, *str2;
+	size_t size1, size2;
+	bool ret = false;
+
 	cache = memcache_init(NULL, 100);
 
 	if (cache == NULL) {
@@ -5342,7 +5347,33 @@ static bool run_local_memcache(int dummy)
 	}
 
 	TALLOC_FREE(cache);
-	return true;
+
+	cache = memcache_init(NULL, 0);
+
+	mem_ctx = talloc_init("foo");
+
+	str1 = talloc_strdup(mem_ctx, "string1");
+	str2 = talloc_strdup(mem_ctx, "string2");
+
+	memcache_add_talloc(cache, SINGLETON_CACHE_TALLOC,
+			    data_blob_string_const("torture"), str1);
+	size1 = talloc_total_size(cache);
+
+	memcache_add_talloc(cache, SINGLETON_CACHE_TALLOC,
+			    data_blob_string_const("torture"), str2);
+	size2 = talloc_total_size(cache);
+
+	printf("size1=%d, size2=%d\n", (int)size1, (int)size2);
+
+	if (size2 > size1) {
+		printf("memcache leaks memory!\n");
+		goto fail;
+	}
+
+	ret = true;
+ fail:
+	TALLOC_FREE(cache);
+	return ret;
 }
 
 static double create_procs(bool (*fn)(int), bool *result)