Index: uspace/lib/c/generic/vfs/vfs.c
===================================================================
--- uspace/lib/c/generic/vfs/vfs.c	(revision 569165335726a0aaf905efcf4640fecff6476512)
+++ uspace/lib/c/generic/vfs/vfs.c	(revision 27833d82536aab87f18f2072179b5d4defc41c5b)
@@ -69,4 +69,5 @@
 	char *ncwd_path;
 	char *ncwd_path_nc;
+	size_t total_size; 
 
 	fibril_mutex_lock(&cwd_mutex);
@@ -77,14 +78,16 @@
 			return NULL;
 		}
-		ncwd_path_nc = malloc(cwd_size + 1 + size + 1);
+		total_size = cwd_size + 1 + size + 1;
+		ncwd_path_nc = malloc(total_size);
 		if (!ncwd_path_nc) {
 			fibril_mutex_unlock(&cwd_mutex);
 			return NULL;
 		}
-		str_cpy(ncwd_path_nc, cwd_size + 1 + size + 1, cwd_path);
+		str_cpy(ncwd_path_nc, total_size, cwd_path);
 		ncwd_path_nc[cwd_size] = '/';
 		ncwd_path_nc[cwd_size + 1] = '\0';
 	} else {
-		ncwd_path_nc = malloc(size + 1);
+		total_size = size + 1;
+		ncwd_path_nc = malloc(total_size);
 		if (!ncwd_path_nc) {
 			fibril_mutex_unlock(&cwd_mutex);
@@ -93,5 +96,5 @@
 		ncwd_path_nc[0] = '\0';
 	}
-	str_append(ncwd_path_nc, cwd_size + 1 + size + 1, path);
+	str_append(ncwd_path_nc, total_size, path);
 	ncwd_path = canonify(ncwd_path_nc, retlen);
 	if (!ncwd_path) {
Index: uspace/srv/fs/fat/fat_ops.c
===================================================================
--- uspace/srv/fs/fat/fat_ops.c	(revision 569165335726a0aaf905efcf4640fecff6476512)
+++ uspace/srv/fs/fat/fat_ops.c	(revision 27833d82536aab87f18f2072179b5d4defc41c5b)
@@ -325,4 +325,5 @@
 		    uint16_t_le2host(d->firstc));
 		if (rc != EOK) {
+			(void) block_put(b);
 			(void) fat_node_put(FS_NODE(nodep));
 			return rc;