[src/trunk]: src/sys/net - bpf_validate_ext: fix memword validation in BPF_ST...

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

details:   https://anonhg.NetBSD.org/src/rev/d54f93f3da96
branches:  trunk
changeset: 796909:d54f93f3da96
user:      rmind <rmind%NetBSD.org@localhost>
date:      Tue Jun 24 22:27:40 2014 +0000

description:
- bpf_validate_ext: fix memword validation in BPF_ST/BPF_STX case.
- bpf_set_extmem: check the number of words against BPF_MAX_MEMWORDS.

diffstat:

 sys/net/bpf_filter.c |  11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diffs (39 lines):

diff -r 15a5e595959b -r d54f93f3da96 sys/net/bpf_filter.c
--- a/sys/net/bpf_filter.c      Tue Jun 24 22:24:18 2014 +0000
+++ b/sys/net/bpf_filter.c      Tue Jun 24 22:27:40 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bpf_filter.c,v 1.63 2014/06/24 22:19:36 rmind Exp $    */
+/*     $NetBSD: bpf_filter.c,v 1.64 2014/06/24 22:27:40 rmind Exp $    */
 
 /*-
  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bpf_filter.c,v 1.63 2014/06/24 22:19:36 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bpf_filter.c,v 1.64 2014/06/24 22:27:40 rmind Exp $");
 
 #if 0
 #if !(defined(lint) || defined(KERNEL))
@@ -79,8 +79,9 @@
 int
 bpf_set_extmem(bpf_ctx_t *bc, size_t nwords, bpf_memword_init_t preinited)
 {
-       /* XXX check arguments */
-
+       if (nwords > BPF_MAX_MEMWORDS) {
+               return EINVAL;
+       }
        bc->extwords = nwords;
        bc->preinited = preinited;
        return 0;
@@ -661,7 +662,7 @@
                                goto out;
 #if defined(KERNEL) || defined(_KERNEL)
                        /* validate the memory word */
-                       invalid &= ~BPF_MEMWORD_INIT(1 << p->k);
+                       invalid &= ~BPF_MEMWORD_INIT(p->k);
 #endif
                        break;
                case BPF_ALU: