Fix deadlock in default handler

Author: KFilipek

src/libumf.c

@@ -103,25 +103,16 @@ umf_result_t umfCtlGet(const char *name, void *ctx, void *arg, size_t size) {
     if (name == NULL || arg == NULL) {
         return UMF_RESULT_ERROR_INVALID_ARGUMENT;
     }
-    // using ctx is disallowed for default settings
-    if (ctx && strstr(name, ".default.")) {
-        return UMF_RESULT_ERROR_INVALID_ARGUMENT;
-    }
     return ctl_query(NULL, ctx, CTL_QUERY_PROGRAMMATIC, name, CTL_QUERY_READ,
-                     arg, size)
-               ? UMF_RESULT_ERROR_UNKNOWN
-               : UMF_RESULT_SUCCESS;
+                     arg, size);
 }
 
 umf_result_t umfCtlSet(const char *name, void *ctx, void *arg, size_t size) {
     // Context can be NULL when setting defaults
     if (name == NULL || arg == NULL || size == 0) {
         return UMF_RESULT_ERROR_INVALID_ARGUMENT;
     }
-    // using ctx is disallowed for default settings
-    if (ctx && strstr(name, ".default.")) {
-        return UMF_RESULT_ERROR_INVALID_ARGUMENT;
-    }
+
     return ctl_query(NULL, ctx, CTL_QUERY_PROGRAMMATIC, name, CTL_QUERY_WRITE,
                      arg, size)
                ? UMF_RESULT_ERROR_UNKNOWN

src/memory_pool.c

@@ -57,6 +57,13 @@ static int CTL_SUBTREE_HANDLER(default)(void *ctx,
     (void)indexes, (void)source, (void)ctx;
     utils_init_once(&mem_pool_ctl_initialized, ctl_init);
     utils_mutex_lock(&ctl_mtx);
+
+    // using ctx is disallowed for default settings
+    if (ctx && strstr(extra_name, "default")) {
+        utils_mutex_unlock(&ctl_mtx);
+        return UMF_RESULT_ERROR_INVALID_ARGUMENT;
+    }
+
     if (queryType == CTL_QUERY_WRITE) {
         int i = 0;
         for (; i < UMF_DEFAULT_SIZE; i++) {
@@ -69,6 +76,7 @@ static int CTL_SUBTREE_HANDLER(default)(void *ctx,
         }
         if (UMF_DEFAULT_SIZE == i) {
             LOG_ERR("Default entries array is full");
+            utils_mutex_unlock(&ctl_mtx);
             return UMF_RESULT_ERROR_OUT_OF_RESOURCES;
         }
     } else if (queryType == CTL_QUERY_READ) {
@@ -81,6 +89,7 @@ static int CTL_SUBTREE_HANDLER(default)(void *ctx,
         }
         if (UMF_DEFAULT_SIZE == i) {
             LOG_WARN("Wrong path name: %s", extra_name);
+            utils_mutex_unlock(&ctl_mtx);
             return UMF_RESULT_ERROR_INVALID_ARGUMENT;
         }
     }