Index: uspace/srv/vfs/vfs_ops.c
===================================================================
--- uspace/srv/vfs/vfs_ops.c	(revision 753bca36deef6be542a11061ac60bd262f76f43f)
+++ uspace/srv/vfs/vfs_ops.c	(revision 10056483ad392d0bac78518e04b2d07a4a811a56)
@@ -1355,4 +1355,5 @@
 		int ret = vfs_close_internal(newfile);
 		if (ret != EOK) {
+			fibril_mutex_unlock(&oldfile->lock);
 			ipc_answer_0(rid, ret);
 			return;
@@ -1361,4 +1362,5 @@
 		ret = vfs_fd_free(newfd);
 		if (ret != EOK) {
+			fibril_mutex_unlock(&oldfile->lock);
 			ipc_answer_0(rid, ret);
 			return;