The security_sb_post_mountroot() hook is long-since obsolete, and is
fundamentally broken: it is never invoked if someone uses initramfs.
This is particularly damaging, because the existence of this hook has
been used as motivation for not using initramfs.
Stephen Smalley confirmed on 2007-07-19 that this hook was originally
used by SELinux but can now be safely removed:
http://marc.info/?l=linux-kernel&m=118485683612916&w=2
Cc: Stephen Smalley <[email protected]>
Cc: James Morris <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: Chris Wright <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
---
include/linux/security.h | 8 --------
init/do_mounts.c | 1 -
security/dummy.c | 6 ------
security/security.c | 5 -----
4 files changed, 0 insertions(+), 20 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index ac05083..21185bc 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -243,9 +243,6 @@ struct request_sock;
* @mnt contains the mounted file system.
* @flags contains the new filesystem flags.
* @data contains the filesystem-specific data.
- * @sb_post_mountroot:
- * Update the security module's state when the root filesystem is mounted.
- * This hook is only called if the mount was successful.
* @sb_post_addmount:
* Update the security module's state when a filesystem is mounted.
* This hook is called any time a mount is successfully grafetd to
@@ -1235,7 +1232,6 @@ struct security_operations {
void (*sb_umount_busy) (struct vfsmount * mnt);
void (*sb_post_remount) (struct vfsmount * mnt,
unsigned long flags, void *data);
- void (*sb_post_mountroot) (void);
void (*sb_post_addmount) (struct vfsmount * mnt,
struct nameidata * mountpoint_nd);
int (*sb_pivotroot) (struct nameidata * old_nd,
@@ -1495,7 +1491,6 @@ int security_sb_umount(struct vfsmount *mnt, int flags);
void security_sb_umount_close(struct vfsmount *mnt);
void security_sb_umount_busy(struct vfsmount *mnt);
void security_sb_post_remount(struct vfsmount *mnt, unsigned long flags, void *data);
-void security_sb_post_mountroot(void);
void security_sb_post_addmount(struct vfsmount *mnt, struct nameidata *mountpoint_nd);
int security_sb_pivotroot(struct nameidata *old_nd, struct nameidata *new_nd);
void security_sb_post_pivotroot(struct nameidata *old_nd, struct nameidata *new_nd);
@@ -1777,9 +1772,6 @@ static inline void security_sb_post_remount (struct vfsmount *mnt,
unsigned long flags, void *data)
{ }
-static inline void security_sb_post_mountroot (void)
-{ }
-
static inline void security_sb_post_addmount (struct vfsmount *mnt,
struct nameidata *mountpoint_nd)
{ }
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 4efa1e5..31b2185 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -470,6 +470,5 @@ void __init prepare_namespace(void)
out:
sys_mount(".", "/", NULL, MS_MOVE, NULL);
sys_chroot(".");
- security_sb_post_mountroot();
}
diff --git a/security/dummy.c b/security/dummy.c
index 3ccfbbe..1c5ab2b 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -225,11 +225,6 @@ static void dummy_sb_post_remount (struct vfsmount *mnt, unsigned long flags,
}
-static void dummy_sb_post_mountroot (void)
-{
- return;
-}
-
static void dummy_sb_post_addmount (struct vfsmount *mnt, struct nameidata *nd)
{
return;
@@ -994,7 +989,6 @@ void security_fixup_ops (struct security_operations *ops)
set_to_dummy_if_null(ops, sb_umount_close);
set_to_dummy_if_null(ops, sb_umount_busy);
set_to_dummy_if_null(ops, sb_post_remount);
- set_to_dummy_if_null(ops, sb_post_mountroot);
set_to_dummy_if_null(ops, sb_post_addmount);
set_to_dummy_if_null(ops, sb_pivotroot);
set_to_dummy_if_null(ops, sb_post_pivotroot);
diff --git a/security/security.c b/security/security.c
index 0e1f1f1..fb6767b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -288,11 +288,6 @@ void security_sb_post_remount(struct vfsmount *mnt, unsigned long flags, void *d
security_ops->sb_post_remount(mnt, flags, data);
}
-void security_sb_post_mountroot(void)
-{
- security_ops->sb_post_mountroot();
-}
-
void security_sb_post_addmount(struct vfsmount *mnt, struct nameidata *mountpoint_nd)
{
security_ops->sb_post_addmount(mnt, mountpoint_nd);
--
1.5.3.6
--- "H. Peter Anvin" <[email protected]> wrote:
> The security_sb_post_mountroot() hook is long-since obsolete, and is
> fundamentally broken: it is never invoked if someone uses initramfs.
> This is particularly damaging, because the existence of this hook has
> been used as motivation for not using initramfs.
>
> Stephen Smalley confirmed on 2007-07-19 that this hook was originally
> used by SELinux but can now be safely removed:
>
> http://marc.info/?l=linux-kernel&m=118485683612916&w=2
>
> Cc: Stephen Smalley <[email protected]>
> Cc: James Morris <[email protected]>
> Cc: Eric Paris <[email protected]>
> Cc: Chris Wright <[email protected]>
> Signed-off-by: H. Peter Anvin <[email protected]>
It is also the case that Smack does not use this hook.
It can be removed as far as I'm concerned.
Casey Schaufler
[email protected]
On Sat, 29 Dec 2007, H. Peter Anvin wrote:
> The security_sb_post_mountroot() hook is long-since obsolete, and is
> fundamentally broken: it is never invoked if someone uses initramfs.
> This is particularly damaging, because the existence of this hook has
> been used as motivation for not using initramfs.
>
> Stephen Smalley confirmed on 2007-07-19 that this hook was originally
> used by SELinux but can now be safely removed:
>
> http://marc.info/?l=linux-kernel&m=118485683612916&w=2
Thanks.
Applied to
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6.git#for-akpm
--
James Morris
<[email protected]>