diff -urN old/shell/ash.c new/shell/ash.c
--- old/shell/ash.c	2018-11-06 21:47:50.000000000 +0800
+++ new/shell/ash.c	2018-11-06 21:55:43.337608907 +0800
@@ -9011,6 +9011,7 @@
 	int checkexit = 0;
 	int (*evalfn)(union node *, int);
 	int status = 0;
+	struct stackmark smark;
 
 	if (n == NULL) {
 		TRACE(("evaltree(NULL) called\n"));
@@ -9031,6 +9032,7 @@
 		status = !evaltree(n->nnot.com, EV_TESTED);
 		goto setstatus;
 	case NREDIR:
+		setstackmark(&smark);
 		expredir(n->nredir.redirect);
 		pushredir(n->nredir.redirect);
 		status = redirectsafe(n->nredir.redirect, REDIR_PUSH);
@@ -9042,6 +9044,7 @@
 		}
 		if (n->nredir.redirect)
 			popredir(/*drop:*/ 0);
+		popstackmark(&smark);
 		goto setstatus;
 	case NCMD:
 		evalfn = evalcommand;