[Guile-commits] 01/10: Fix write beyond stack boundary in vm-engine.c

[Andy Wingo]

wingo pushed a commit to branch master
in repository guile.

commit bb051f2154da5c479fcaed139090a859a66fde6b
Author: Andy Wingo <address@hidden>
Date:   Fri Jun 5 00:10:08 2015 +0200

    Fix write beyond stack boundary in vm-engine.c
    
    * libguile/vm-engine.c (RETURN_ONE_VALUE, RETURN_VALUE_LIST): These
      helpers, used in subr-call and the like, might not actually have
      enough space to push the return values.  Use ALLOC_FRAME instead of
      RESET_FRAME, for that reason.
---
 libguile/vm-engine.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/libguile/vm-engine.c b/libguile/vm-engine.c
index ec112b2..7e752dd 100644
--- a/libguile/vm-engine.c
+++ b/libguile/vm-engine.c
@@ -259,6 +259,7 @@
     SCM val = ret;                                      \
     SCM *old_fp;                                        \
     VM_HANDLE_INTERRUPTS;                               \
+    ALLOC_FRAME (2);                                   \
     old_fp = fp;                                        \
     ip = SCM_FRAME_RETURN_ADDRESS (fp);                 \
     fp = vp->fp = SCM_FRAME_DYNAMIC_LINK (fp);          \
@@ -278,10 +279,10 @@
   do {                                                  \
     SCM vals = vals_;                                   \
     VM_HANDLE_INTERRUPTS;                               \
+    ALLOC_FRAME (3);                                   \
     fp[0] = vm_builtin_apply;                           \
     fp[1] = vm_builtin_values;                          \
     fp[2] = vals;                                       \
-    RESET_FRAME (3);                                    \
     ip = (scm_t_uint32 *) vm_builtin_apply_code;        \
     goto op_tail_apply;                                 \
   } while (0)