[src/trunk]: src/sys/compat/netbsd32 Wrong logic. Here, userland can control ...

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

details:   https://anonhg.NetBSD.org/src/rev/c3c7486fd582
branches:  trunk
changeset: 809789:c3c7486fd582
user:      maxv <maxv%NetBSD.org@localhost>
date:      Sun Aug 02 07:37:57 2015 +0000

description:
Wrong logic. Here, userland can control the size and the data copied, which
basically means it can overflow kernel memory.

ok martin@ christos@

diffstat:

 sys/compat/netbsd32/netbsd32_ioctl.c |  8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diffs (36 lines):

diff -r c699a04272de -r c3c7486fd582 sys/compat/netbsd32/netbsd32_ioctl.c
--- a/sys/compat/netbsd32/netbsd32_ioctl.c      Sun Aug 02 07:25:40 2015 +0000
+++ b/sys/compat/netbsd32/netbsd32_ioctl.c      Sun Aug 02 07:37:57 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: netbsd32_ioctl.c,v 1.81 2015/06/01 16:07:27 roy Exp $  */
+/*     $NetBSD: netbsd32_ioctl.c,v 1.82 2015/08/02 07:37:57 maxv Exp $ */
 
 /*
  * Copyright (c) 1998, 2001 Matthew R. Green
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_ioctl.c,v 1.81 2015/06/01 16:07:27 roy Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_ioctl.c,v 1.82 2015/08/02 07:37:57 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -144,7 +144,7 @@
        strlcpy(ifap->ifap_name, ifap32->ifap_name, sizeof(ifap->ifap_name));
        ifap->ifap_preference = ifap32->ifap_preference;
        memcpy(&ifap->ifap_addr, &ifap32->ifap_addr,
-           max(ifap32->ifap_addr.ss_len, _SS_MAXSIZE));
+           min(ifap32->ifap_addr.ss_len, _SS_MAXSIZE));
 }
 
 static inline void
@@ -547,7 +547,7 @@
        strlcpy(ifap32->ifap_name, ifap->ifap_name, sizeof(ifap32->ifap_name));
        ifap32->ifap_preference = ifap->ifap_preference;
        memcpy(&ifap32->ifap_addr, &ifap->ifap_addr,
-           max(ifap->ifap_addr.ss_len, _SS_MAXSIZE));
+           min(ifap->ifap_addr.ss_len, _SS_MAXSIZE));
 }
 
 static inline void