Smack: domain transition protections (v3)

Protections for domain transition:

- BPRM unsafe flags
- Secureexec
- Clear unsafe personality bits.
- Clear parent death signal

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
This commit is contained in:
Jarkko Sakkinen 2011-10-07 09:27:53 +03:00 committed by Casey Schaufler
parent 975d5e55c2
commit 84088ba239

View file

@ -5,12 +5,13 @@
*
* Authors:
* Casey Schaufler <casey@schaufler-ca.com>
* Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com>
* Jarkko Sakkinen <jarkko.sakkinen@intel.com>
*
* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
* Paul Moore <paul@paul-moore.com>
* Copyright (C) 2010 Nokia Corporation
* Copyright (C) 2011 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2,
@ -449,9 +450,9 @@ static int smack_sb_umount(struct vfsmount *mnt, int flags)
*/
static int smack_bprm_set_creds(struct linux_binprm *bprm)
{
struct task_smack *tsp = bprm->cred->security;
struct inode *inode = bprm->file->f_path.dentry->d_inode;
struct task_smack *bsp = bprm->cred->security;
struct inode_smack *isp;
struct dentry *dp;
int rc;
rc = cap_bprm_set_creds(bprm);
@ -461,22 +462,50 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm)
if (bprm->cred_prepared)
return 0;
if (bprm->file == NULL || bprm->file->f_dentry == NULL)
isp = inode->i_security;
if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
return 0;
dp = bprm->file->f_dentry;
if (bprm->unsafe)
return -EPERM;
if (dp->d_inode == NULL)
return 0;
isp = dp->d_inode->i_security;
if (isp->smk_task != NULL)
tsp->smk_task = isp->smk_task;
bsp->smk_task = isp->smk_task;
bprm->per_clear |= PER_CLEAR_ON_SETID;
return 0;
}
/**
* smack_bprm_committing_creds - Prepare to install the new credentials
* from bprm.
*
* @bprm: binprm for exec
*/
static void smack_bprm_committing_creds(struct linux_binprm *bprm)
{
struct task_smack *bsp = bprm->cred->security;
if (bsp->smk_task != bsp->smk_forked)
current->pdeath_signal = 0;
}
/**
* smack_bprm_secureexec - Return the decision to use secureexec.
* @bprm: binprm for exec
*
* Returns 0 on success.
*/
static int smack_bprm_secureexec(struct linux_binprm *bprm)
{
struct task_smack *tsp = current_security();
int ret = cap_bprm_secureexec(bprm);
if (!ret && (tsp->smk_task != tsp->smk_forked))
ret = 1;
return ret;
}
/*
* Inode hooks
*/
@ -3467,6 +3496,8 @@ struct security_operations smack_ops = {
.sb_umount = smack_sb_umount,
.bprm_set_creds = smack_bprm_set_creds,
.bprm_committing_creds = smack_bprm_committing_creds,
.bprm_secureexec = smack_bprm_secureexec,
.inode_alloc_security = smack_inode_alloc_security,
.inode_free_security = smack_inode_free_security,