Only override size of chunk if we're not given the actual length.

Fixes malloc_conceal...freezero with malloc options C and/or G.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/lib/libc/stdlib/malloc.c b/src/lib/libc/stdlib/malloc.c
index ff41f61385..f2e82679e9 100644
--- a/src/lib/libc/stdlib/malloc.c
+++ b/src/lib/libc/stdlib/malloc.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: malloc.c,v 1.260 2019/05/10 15:03:24 otto Exp $       */
+/*      $OpenBSD: malloc.c,v 1.261 2019/05/23 06:43:18 otto Exp $       */
 /*
  * Copyright (c) 2008, 2010, 2011, 2016 Otto Moerbeek <otto@drijf.net>
  * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org>
@@ -1371,7 +1371,8 @@ ofree(struct dir_info **argpool, void *p, int clear, int check, size_t argsz)
         REALSIZE(sz, r);
         if (pool->mmap_flag) {
                 clear = 1;
-                argsz = sz;
+                if (!check)
+                        argsz = sz;
         }
         if (check) {
                 if (sz <= MALLOC_MAXCHUNK) {