[src/trunk]: src/sys/kern On a verbose kernel boot show why executables are d...

[reinoud <reinoud%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a2cab5dc6b69
branches:  trunk
changeset: 768744:a2cab5dc6b69
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Thu Aug 25 19:14:07 2011 +0000

description:
On a verbose kernel boot show why executables are denied due to their start
adresses. This will hardly ever occure in real-life.

diffstat:

 sys/kern/kern_exec.c |  17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)

diffs (46 lines):

diff -r 2c322380d67e -r a2cab5dc6b69 sys/kern/kern_exec.c
--- a/sys/kern/kern_exec.c      Thu Aug 25 19:09:46 2011 +0000
+++ b/sys/kern/kern_exec.c      Thu Aug 25 19:14:07 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_exec.c,v 1.317 2011/08/08 12:08:53 manu Exp $     */
+/*     $NetBSD: kern_exec.c,v 1.318 2011/08/25 19:14:07 reinoud Exp $  */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -59,7 +59,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.317 2011/08/08 12:08:53 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.318 2011/08/25 19:14:07 reinoud Exp $");
 
 #include "opt_ktrace.h"
 #include "opt_modular.h"
@@ -370,8 +370,17 @@
                newerror = (*execsw[i]->es_makecmds)(l, epp);
 
                if (!newerror) {
-                       /* Seems ok: check that entry point is sane */
+                       /* Seems ok: check that entry point is not too high */
                        if (epp->ep_entry > VM_MAXUSER_ADDRESS) {
+                               aprint_verbose("check_exec: rejecting due to "
+                                       "too high entry address\n");
+                               error = ENOEXEC;
+                               break;
+                       }
+                       /* Seems ok: check that entry point is not too low */
+                       if (epp->ep_entry < VM_MIN_ADDRESS) {
+                               aprint_verbose("check_exec: rejecting due to "
+                                       "too low entry address\n");
                                error = ENOEXEC;
                                break;
                        }
@@ -380,6 +389,8 @@
                        if ((epp->ep_tsize > MAXTSIZ) ||
                            (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit
                                                    [RLIMIT_DATA].rlim_cur)) {
+                               aprint_debug("check_exec: rejecting due to "
+                                       "limits\n");
                                error = ENOMEM;
                                break;
                        }