[src/trunk]: src/sys/ufs/ffs Add some checks in ffs_superblock_validate():

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

details:   https://anonhg.NetBSD.org/src/rev/40147d0ad0fa
branches:  trunk
changeset: 336113:40147d0ad0fa
user:      maxv <maxv%NetBSD.org@localhost>
date:      Fri Feb 13 16:59:52 2015 +0000

description:
Add some checks in ffs_superblock_validate():
 - fs_bsize < MINBSIZE
 - !powerof2(fs_bsize)
 - !powerof2(fs->fs_fsize)
 - fs_bsize < fs->fs_fsize

Based on makefs/ffs.

diffstat:

 sys/ufs/ffs/ffs_vfsops.c |  16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)

diffs (42 lines):

diff -r f5b8883ba1d1 -r 40147d0ad0fa sys/ufs/ffs/ffs_vfsops.c
--- a/sys/ufs/ffs/ffs_vfsops.c  Fri Feb 13 16:56:57 2015 +0000
+++ b/sys/ufs/ffs/ffs_vfsops.c  Fri Feb 13 16:59:52 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ffs_vfsops.c,v 1.307 2015/02/13 15:52:29 maxv Exp $    */
+/*     $NetBSD: ffs_vfsops.c,v 1.308 2015/02/13 16:59:52 maxv Exp $    */
 
 /*-
  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ffs_vfsops.c,v 1.307 2015/02/13 15:52:29 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ffs_vfsops.c,v 1.308 2015/02/13 16:59:52 maxv Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_ffs.h"
@@ -912,12 +912,22 @@
                return 0;
 
        /* Check the file system blocksize */
-       if (fs_bsize > MAXBSIZE)
+       if (fs_bsize > MAXBSIZE || fs_bsize < MINBSIZE)
+               return 0;
+       if (!powerof2(fs_bsize))
+               return 0;
+
+       /* Check the size of frag blocks */
+       if (!powerof2(fs->fs_fsize))
                return 0;
 
        if (fs->fs_size == 0)
                return 0;
 
+       /* Block size cannot be smaller than fragment size */
+       if (fs_bsize < fs->fs_fsize)
+               return 0;
+
        return 1;
 }