diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 3c379f9..e764416 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -467,11 +467,13 @@
          * preallocating synchronously.
          */
         if (context->num_threads == 1 && !async) {
+            ret = 0;
             if (qemu_madvise(area, hpagesize * numpages,
                              QEMU_MADV_POPULATE_WRITE)) {
-                return -errno;
+                ret = -errno;
             }
-            return 0;
+            g_free(context);
+            return ret;
         }
         touch_fn = do_madv_populate_write_pages;
     } else {