[src/netbsd-8]: src/sys/kern Pull up following revision(s) (requested by mart...

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

details:   https://anonhg.NetBSD.org/src/rev/df385d65aaa0
branches:  netbsd-8
changeset: 850894:df385d65aaa0
user:      snj <snj%NetBSD.org@localhost>
date:      Tue Aug 01 23:26:58 2017 +0000

description:
Pull up following revision(s) (requested by martin in ticket #168):
        sys/kern/kern_malloc.c: revision 1.146
Avoid integer overflow in kern_malloc(). Reported by Ilja Van Sprundel.

diffstat:

 sys/kern/kern_malloc.c |  9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diffs (30 lines):

diff -r 42da35b1b946 -r df385d65aaa0 sys/kern/kern_malloc.c
--- a/sys/kern/kern_malloc.c    Tue Aug 01 23:25:11 2017 +0000
+++ b/sys/kern/kern_malloc.c    Tue Aug 01 23:26:58 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_malloc.c,v 1.145 2015/02/06 18:21:29 maxv Exp $   */
+/*     $NetBSD: kern_malloc.c,v 1.145.10.1 2017/08/01 23:26:58 snj Exp $       */
 
 /*
  * Copyright (c) 1987, 1991, 1993
@@ -70,7 +70,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_malloc.c,v 1.145 2015/02/06 18:21:29 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_malloc.c,v 1.145.10.1 2017/08/01 23:26:58 snj Exp $");
 
 #include <sys/param.h>
 #include <sys/malloc.h>
@@ -105,7 +105,10 @@
        void *p;
 
        if (size >= PAGE_SIZE) {
-               allocsize = PAGE_SIZE + size; /* for page alignment */
+               if (size > (ULONG_MAX-PAGE_SIZE))
+                       allocsize = ULONG_MAX;  /* this will fail later */
+               else
+                       allocsize = PAGE_SIZE + size; /* for page alignment */
                hdroffset = PAGE_SIZE - sizeof(struct malloc_header);
        } else {
                allocsize = sizeof(struct malloc_header) + size;