[Guile-commits] 01/01: Avoid reading garbage from dynstack

[Andy Wingo]

wingo pushed a commit to branch master
in repository guile.

commit 5048a8afbc00e3e0a65a5d2ffccfec666ec5a68b
Author: Andy Wingo <address@hidden>
Date:   Sun Feb 12 18:02:53 2017 +0100

    Avoid reading garbage from dynstack
    
    * libguile/dynstack.c (push_dynstack_entry_unchecked): Reset top
      dynstack tag to prevent garbage.
---
 libguile/dynstack.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libguile/dynstack.c b/libguile/dynstack.c
index 652d2b3..1eb1dcf 100644
--- a/libguile/dynstack.c
+++ b/libguile/dynstack.c
@@ -113,6 +113,7 @@ push_dynstack_entry_unchecked (scm_t_dynstack *dynstack,
 
   SCM_DYNSTACK_SET_TAG (dynstack->top, SCM_MAKE_DYNSTACK_TAG (type, flags, 
len));
   dynstack->top += SCM_DYNSTACK_HEADER_LEN + len;
+  SCM_DYNSTACK_SET_TAG (dynstack->top, 0);
   SCM_DYNSTACK_SET_PREV_OFFSET (dynstack->top, SCM_DYNSTACK_HEADER_LEN + len);
 
   return ret;