Module Name: src
Committed By: maxv
Date: Tue Mar 3 17:46:39 UTC 2015
Modified Files:
src/sys/ufs/ffs: ffs_vfsops.c
Log Message:
ffs_reload(): the current implementation blindly guesses critical fields
of the superblock didn't change. Add checks to ensure they didn't change
for real. This prevents several memory corruptions.
To generate a diff of this commit:
cvs rdiff -u -r1.319 -r1.320 src/sys/ufs/ffs/ffs_vfsops.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/ufs/ffs/ffs_vfsops.c
diff -u src/sys/ufs/ffs/ffs_vfsops.c:1.319 src/sys/ufs/ffs/ffs_vfsops.c:1.320
--- src/sys/ufs/ffs/ffs_vfsops.c:1.319 Mon Feb 23 13:38:54 2015
+++ src/sys/ufs/ffs/ffs_vfsops.c Tue Mar 3 17:46:39 2015
@@ -1,4 +1,4 @@
-/* $NetBSD: ffs_vfsops.c,v 1.319 2015/02/23 13:38:54 maxv Exp $ */
+/* $NetBSD: ffs_vfsops.c,v 1.320 2015/03/03 17:46:39 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 1.319 2015/02/23 13:38:54 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ffs_vfsops.c,v 1.320 2015/03/03 17:46:39 maxv Exp $");
#if defined(_KERNEL_OPT)
#include "opt_ffs.h"
@@ -733,12 +733,6 @@ ffs_reload(struct mount *mp, kauth_cred_
#endif
fs->fs_flags &= ~FS_SWAPPED;
- /* We don't want the superblock size to change. */
- if (newfs->fs_sbsize != fs_sbsize) {
- brelse(bp, 0);
- kmem_free(newfs, fs_sbsize);
- return (EINVAL);
- }
if ((newfs->fs_magic != FS_UFS1_MAGIC &&
newfs->fs_magic != FS_UFS2_MAGIC)) {
brelse(bp, 0);
@@ -751,6 +745,20 @@ ffs_reload(struct mount *mp, kauth_cred_
return (EINVAL);
}
+ /*
+ * The current implementation doesn't handle the possibility that
+ * these values may have changed.
+ */
+ if ((newfs->fs_sbsize != fs_sbsize) ||
+ (newfs->fs_cssize != fs->fs_cssize) ||
+ (newfs->fs_contigsumsize != fs->fs_contigsumsize) ||
+ (newfs->fs_ncg != fs->fs_ncg)) {
+ brelse(bp, 0);
+ kmem_free(newfs, fs_sbsize);
+ return (EINVAL);
+ }
+
+
/* Store off old fs_sblockloc for fs_oldfscompat_read. */
sblockloc = fs->fs_sblockloc;
/*
