304 lines
7.1 KiB
C
304 lines
7.1 KiB
C
/*
|
|
* CDDL HEADER START
|
|
*
|
|
* The contents of this file are subject to the terms of the
|
|
* Common Development and Distribution License (the "License").
|
|
* You may not use this file except in compliance with the License.
|
|
*
|
|
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
|
|
* or http://www.opensolaris.org/os/licensing.
|
|
* See the License for the specific language governing permissions
|
|
* and limitations under the License.
|
|
*
|
|
* When distributing Covered Code, include this CDDL HEADER in each
|
|
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
|
|
* If applicable, add the following below this CDDL HEADER, with the
|
|
* fields enclosed by brackets "[]" replaced with your own identifying
|
|
* information: Portions Copyright [yyyy] [name of copyright owner]
|
|
*
|
|
* CDDL HEADER END
|
|
*/
|
|
|
|
/*
|
|
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
|
|
* Copyright 2013, Joyent, Inc. All rights reserved.
|
|
* Copyright (C) 2016 Lawrence Livermore National Security, LLC.
|
|
*
|
|
* For Linux the vast majority of this enforcement is already handled via
|
|
* the standard Linux VFS permission checks. However certain administrative
|
|
* commands which bypass the standard mechanisms may need to make use of
|
|
* this functionality.
|
|
*/
|
|
|
|
#include <sys/policy.h>
|
|
#include <linux/security.h>
|
|
#include <linux/vfs_compat.h>
|
|
|
|
/*
|
|
* The passed credentials cannot be directly verified because Linux only
|
|
* provides and interface to check the *current* process credentials. In
|
|
* order to handle this the capable() test is only run when the passed
|
|
* credentials match the current process credentials or the kcred. In
|
|
* all other cases this function must fail and return the passed err.
|
|
*/
|
|
static int
|
|
priv_policy(const cred_t *cr, int capability, boolean_t all, int err)
|
|
{
|
|
ASSERT3S(all, ==, B_FALSE);
|
|
|
|
if (cr != CRED() && (cr != kcred))
|
|
return (err);
|
|
|
|
if (!capable(capability))
|
|
return (err);
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Checks for operations that are either client-only or are used by
|
|
* both clients and servers.
|
|
*/
|
|
int
|
|
secpolicy_nfs(const cred_t *cr)
|
|
{
|
|
return (priv_policy(cr, CAP_SYS_ADMIN, B_FALSE, EPERM));
|
|
}
|
|
|
|
/*
|
|
* Catch all system configuration.
|
|
*/
|
|
int
|
|
secpolicy_sys_config(const cred_t *cr, boolean_t checkonly)
|
|
{
|
|
return (priv_policy(cr, CAP_SYS_ADMIN, B_FALSE, EPERM));
|
|
}
|
|
|
|
/*
|
|
* Like secpolicy_vnode_access() but we get the actual wanted mode and the
|
|
* current mode of the file, not the missing bits.
|
|
*
|
|
* Enforced in the Linux VFS.
|
|
*/
|
|
int
|
|
secpolicy_vnode_access2(const cred_t *cr, struct inode *ip, uid_t owner,
|
|
mode_t curmode, mode_t wantmode)
|
|
{
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* This is a special routine for ZFS; it is used to determine whether
|
|
* any of the privileges in effect allow any form of access to the
|
|
* file. There's no reason to audit this or any reason to record
|
|
* this. More work is needed to do the "KPLD" stuff.
|
|
*/
|
|
int
|
|
secpolicy_vnode_any_access(const cred_t *cr, struct inode *ip, uid_t owner)
|
|
{
|
|
if (crgetfsuid(cr) == owner)
|
|
return (0);
|
|
|
|
if (zpl_inode_owner_or_capable(ip))
|
|
return (0);
|
|
|
|
if (priv_policy(cr, CAP_DAC_OVERRIDE, B_FALSE, EPERM) == 0)
|
|
return (0);
|
|
|
|
if (priv_policy(cr, CAP_DAC_READ_SEARCH, B_FALSE, EPERM) == 0)
|
|
return (0);
|
|
|
|
return (EPERM);
|
|
}
|
|
|
|
/*
|
|
* Determine if subject can chown owner of a file.
|
|
*/
|
|
int
|
|
secpolicy_vnode_chown(const cred_t *cr, uid_t owner)
|
|
{
|
|
if (crgetfsuid(cr) == owner)
|
|
return (0);
|
|
|
|
return (priv_policy(cr, CAP_FOWNER, B_FALSE, EPERM));
|
|
}
|
|
|
|
/*
|
|
* Determine if subject can change group ownership of a file.
|
|
*/
|
|
int
|
|
secpolicy_vnode_create_gid(const cred_t *cr)
|
|
{
|
|
return (priv_policy(cr, CAP_SETGID, B_FALSE, EPERM));
|
|
}
|
|
|
|
/*
|
|
* Policy determines whether we can remove an entry from a directory,
|
|
* regardless of permission bits.
|
|
*/
|
|
int
|
|
secpolicy_vnode_remove(const cred_t *cr)
|
|
{
|
|
return (priv_policy(cr, CAP_FOWNER, B_FALSE, EPERM));
|
|
}
|
|
|
|
/*
|
|
* Determine that subject can modify the mode of a file. allzone privilege
|
|
* needed when modifying root owned object.
|
|
*/
|
|
int
|
|
secpolicy_vnode_setdac(const cred_t *cr, uid_t owner)
|
|
{
|
|
if (crgetfsuid(cr) == owner)
|
|
return (0);
|
|
|
|
return (priv_policy(cr, CAP_FOWNER, B_FALSE, EPERM));
|
|
}
|
|
|
|
/*
|
|
* Are we allowed to retain the set-uid/set-gid bits when
|
|
* changing ownership or when writing to a file?
|
|
* "issuid" should be true when set-uid; only in that case
|
|
* root ownership is checked (setgid is assumed).
|
|
*
|
|
* Enforced in the Linux VFS.
|
|
*/
|
|
int
|
|
secpolicy_vnode_setid_retain(const cred_t *cr, boolean_t issuidroot)
|
|
{
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Determine that subject can set the file setgid flag.
|
|
*/
|
|
int
|
|
secpolicy_vnode_setids_setgids(const cred_t *cr, gid_t gid)
|
|
{
|
|
if (crgetfsgid(cr) != gid && !groupmember(gid, cr))
|
|
return (priv_policy(cr, CAP_FSETID, B_FALSE, EPERM));
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Determine if the subject can inject faults in the ZFS fault injection
|
|
* framework. Requires all privileges.
|
|
*/
|
|
int
|
|
secpolicy_zinject(const cred_t *cr)
|
|
{
|
|
return (priv_policy(cr, CAP_SYS_ADMIN, B_FALSE, EACCES));
|
|
}
|
|
|
|
/*
|
|
* Determine if the subject has permission to manipulate ZFS datasets
|
|
* (not pools). Equivalent to the SYS_MOUNT privilege.
|
|
*/
|
|
int
|
|
secpolicy_zfs(const cred_t *cr)
|
|
{
|
|
return (priv_policy(cr, CAP_SYS_ADMIN, B_FALSE, EACCES));
|
|
}
|
|
|
|
void
|
|
secpolicy_setid_clear(vattr_t *vap, cred_t *cr)
|
|
{
|
|
if ((vap->va_mode & (S_ISUID | S_ISGID)) != 0 &&
|
|
secpolicy_vnode_setid_retain(cr,
|
|
(vap->va_mode & S_ISUID) != 0 &&
|
|
(vap->va_mask & AT_UID) != 0 && vap->va_uid == 0) != 0) {
|
|
vap->va_mask |= AT_MODE;
|
|
vap->va_mode &= ~(S_ISUID|S_ISGID);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Determine that subject can set the file setid flags.
|
|
*/
|
|
static int
|
|
secpolicy_vnode_setid_modify(const cred_t *cr, uid_t owner)
|
|
{
|
|
if (crgetfsuid(cr) == owner)
|
|
return (0);
|
|
|
|
return (priv_policy(cr, CAP_FSETID, B_FALSE, EPERM));
|
|
}
|
|
|
|
/*
|
|
* Determine that subject can make a file a "sticky".
|
|
*
|
|
* Enforced in the Linux VFS.
|
|
*/
|
|
static int
|
|
secpolicy_vnode_stky_modify(const cred_t *cr)
|
|
{
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
secpolicy_setid_setsticky_clear(struct inode *ip, vattr_t *vap,
|
|
const vattr_t *ovap, cred_t *cr)
|
|
{
|
|
int error;
|
|
|
|
if ((vap->va_mode & S_ISUID) != 0 &&
|
|
(error = secpolicy_vnode_setid_modify(cr,
|
|
ovap->va_uid)) != 0) {
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Check privilege if attempting to set the
|
|
* sticky bit on a non-directory.
|
|
*/
|
|
if (!S_ISDIR(ip->i_mode) && (vap->va_mode & S_ISVTX) != 0 &&
|
|
secpolicy_vnode_stky_modify(cr) != 0) {
|
|
vap->va_mode &= ~S_ISVTX;
|
|
}
|
|
|
|
/*
|
|
* Check for privilege if attempting to set the
|
|
* group-id bit.
|
|
*/
|
|
if ((vap->va_mode & S_ISGID) != 0 &&
|
|
secpolicy_vnode_setids_setgids(cr, ovap->va_gid) != 0) {
|
|
vap->va_mode &= ~S_ISGID;
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Check privileges for setting xvattr attributes
|
|
*/
|
|
int
|
|
secpolicy_xvattr(xvattr_t *xvap, uid_t owner, cred_t *cr, vtype_t vtype)
|
|
{
|
|
return (secpolicy_vnode_chown(cr, owner));
|
|
}
|
|
|
|
/*
|
|
* Check privileges for setattr attributes.
|
|
*
|
|
* Enforced in the Linux VFS.
|
|
*/
|
|
int
|
|
secpolicy_vnode_setattr(cred_t *cr, struct inode *ip, struct vattr *vap,
|
|
const struct vattr *ovap, int flags,
|
|
int unlocked_access(void *, int, cred_t *), void *node)
|
|
{
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Check privileges for links.
|
|
*
|
|
* Enforced in the Linux VFS.
|
|
*/
|
|
int
|
|
secpolicy_basic_link(const cred_t *cr)
|
|
{
|
|
return (0);
|
|
}
|