freebsd-skq/sys/security/mac/mac_syscalls.c
Mateusz Guzik daf63fd2f9 cred: add proc_set_cred helper
The goal here is to provide one place altering process credentials.

This eases debugging and opens up posibilities to do additional work when such
an action is performed.
2015-03-16 00:10:03 +00:00

734 lines
16 KiB
C

/*-
* Copyright (c) 1999-2002, 2006, 2009 Robert N. M. Watson
* Copyright (c) 2001 Ilmar S. Habibulin
* Copyright (c) 2001-2005 Networks Associates Technology, Inc.
* Copyright (c) 2005-2006 SPARTA, Inc.
* Copyright (c) 2008 Apple Inc.
* All rights reserved.
*
* This software was developed by Robert Watson and Ilmar Habibulin for the
* TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research program.
*
* This software was enhanced by SPARTA ISSO under SPAWAR contract
* N66001-04-C-6019 ("SEFOS").
*
* This software was developed at the University of Cambridge Computer
* Laboratory with support from a grant from Google, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/capsicum.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mac.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/socket.h>
#include <sys/pipe.h>
#include <sys/socketvar.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
#include <security/mac/mac_policy.h>
#ifdef MAC
FEATURE(security_mac, "Mandatory Access Control Framework support");
int
sys___mac_get_pid(struct thread *td, struct __mac_get_pid_args *uap)
{
char *elements, *buffer;
struct mac mac;
struct proc *tproc;
struct ucred *tcred;
int error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
tproc = pfind(uap->pid);
if (tproc == NULL)
return (ESRCH);
tcred = NULL; /* Satisfy gcc. */
error = p_cansee(td, tproc);
if (error == 0)
tcred = crhold(tproc->p_ucred);
PROC_UNLOCK(tproc);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
crfree(tcred);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
error = mac_cred_externalize_label(tcred->cr_label, elements,
buffer, mac.m_buflen);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
crfree(tcred);
return (error);
}
int
sys___mac_get_proc(struct thread *td, struct __mac_get_proc_args *uap)
{
char *elements, *buffer;
struct mac mac;
int error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
error = mac_cred_externalize_label(td->td_ucred->cr_label,
elements, buffer, mac.m_buflen);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
int
sys___mac_set_proc(struct thread *td, struct __mac_set_proc_args *uap)
{
struct ucred *newcred, *oldcred;
struct label *intlabel;
struct proc *p;
struct mac mac;
char *buffer;
int error;
if (!(mac_labeled & MPC_OBJECT_CRED))
return (EINVAL);
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
intlabel = mac_cred_label_alloc();
error = mac_cred_internalize_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error)
goto out;
newcred = crget();
p = td->td_proc;
PROC_LOCK(p);
oldcred = p->p_ucred;
error = mac_cred_check_relabel(oldcred, intlabel);
if (error) {
PROC_UNLOCK(p);
crfree(newcred);
goto out;
}
setsugid(p);
crcopy(newcred, oldcred);
mac_cred_relabel(newcred, intlabel);
proc_set_cred(p, newcred);
PROC_UNLOCK(p);
crfree(oldcred);
mac_proc_vm_revoke(td);
out:
mac_cred_label_free(intlabel);
return (error);
}
int
sys___mac_get_fd(struct thread *td, struct __mac_get_fd_args *uap)
{
char *elements, *buffer;
struct label *intlabel;
struct file *fp;
struct mac mac;
struct vnode *vp;
struct pipe *pipe;
struct socket *so;
cap_rights_t rights;
short label_type;
int error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
error = fget(td, uap->fd, cap_rights_init(&rights, CAP_MAC_GET), &fp);
if (error)
goto out;
label_type = fp->f_type;
switch (fp->f_type) {
case DTYPE_FIFO:
case DTYPE_VNODE:
if (!(mac_labeled & MPC_OBJECT_VNODE)) {
error = EINVAL;
goto out_fdrop;
}
vp = fp->f_vnode;
intlabel = mac_vnode_label_alloc();
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
mac_vnode_copy_label(vp->v_label, intlabel);
VOP_UNLOCK(vp, 0);
error = mac_vnode_externalize_label(intlabel, elements,
buffer, mac.m_buflen);
mac_vnode_label_free(intlabel);
break;
case DTYPE_PIPE:
if (!(mac_labeled & MPC_OBJECT_PIPE)) {
error = EINVAL;
goto out_fdrop;
}
pipe = fp->f_data;
intlabel = mac_pipe_label_alloc();
PIPE_LOCK(pipe);
mac_pipe_copy_label(pipe->pipe_pair->pp_label, intlabel);
PIPE_UNLOCK(pipe);
error = mac_pipe_externalize_label(intlabel, elements,
buffer, mac.m_buflen);
mac_pipe_label_free(intlabel);
break;
case DTYPE_SOCKET:
if (!(mac_labeled & MPC_OBJECT_SOCKET)) {
error = EINVAL;
goto out_fdrop;
}
so = fp->f_data;
intlabel = mac_socket_label_alloc(M_WAITOK);
SOCK_LOCK(so);
mac_socket_copy_label(so->so_label, intlabel);
SOCK_UNLOCK(so);
error = mac_socket_externalize_label(intlabel, elements,
buffer, mac.m_buflen);
mac_socket_label_free(intlabel);
break;
default:
error = EINVAL;
}
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
out_fdrop:
fdrop(fp, td);
out:
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
int
sys___mac_get_file(struct thread *td, struct __mac_get_file_args *uap)
{
char *elements, *buffer;
struct nameidata nd;
struct label *intlabel;
struct mac mac;
int error;
if (!(mac_labeled & MPC_OBJECT_VNODE))
return (EINVAL);
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
NDINIT(&nd, LOOKUP, LOCKLEAF | FOLLOW, UIO_USERSPACE,
uap->path_p, td);
error = namei(&nd);
if (error)
goto out;
intlabel = mac_vnode_label_alloc();
mac_vnode_copy_label(nd.ni_vp->v_label, intlabel);
error = mac_vnode_externalize_label(intlabel, elements, buffer,
mac.m_buflen);
NDFREE(&nd, 0);
mac_vnode_label_free(intlabel);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
out:
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
int
sys___mac_get_link(struct thread *td, struct __mac_get_link_args *uap)
{
char *elements, *buffer;
struct nameidata nd;
struct label *intlabel;
struct mac mac;
int error;
if (!(mac_labeled & MPC_OBJECT_VNODE))
return (EINVAL);
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
NDINIT(&nd, LOOKUP, LOCKLEAF | NOFOLLOW, UIO_USERSPACE,
uap->path_p, td);
error = namei(&nd);
if (error)
goto out;
intlabel = mac_vnode_label_alloc();
mac_vnode_copy_label(nd.ni_vp->v_label, intlabel);
error = mac_vnode_externalize_label(intlabel, elements, buffer,
mac.m_buflen);
NDFREE(&nd, 0);
mac_vnode_label_free(intlabel);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
out:
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
int
sys___mac_set_fd(struct thread *td, struct __mac_set_fd_args *uap)
{
struct label *intlabel;
struct pipe *pipe;
struct socket *so;
struct file *fp;
struct mount *mp;
struct vnode *vp;
struct mac mac;
cap_rights_t rights;
char *buffer;
int error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
error = fget(td, uap->fd, cap_rights_init(&rights, CAP_MAC_SET), &fp);
if (error)
goto out;
switch (fp->f_type) {
case DTYPE_FIFO:
case DTYPE_VNODE:
if (!(mac_labeled & MPC_OBJECT_VNODE)) {
error = EINVAL;
goto out_fdrop;
}
intlabel = mac_vnode_label_alloc();
error = mac_vnode_internalize_label(intlabel, buffer);
if (error) {
mac_vnode_label_free(intlabel);
break;
}
vp = fp->f_vnode;
error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
if (error != 0) {
mac_vnode_label_free(intlabel);
break;
}
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
error = vn_setlabel(vp, intlabel, td->td_ucred);
VOP_UNLOCK(vp, 0);
vn_finished_write(mp);
mac_vnode_label_free(intlabel);
break;
case DTYPE_PIPE:
if (!(mac_labeled & MPC_OBJECT_PIPE)) {
error = EINVAL;
goto out_fdrop;
}
intlabel = mac_pipe_label_alloc();
error = mac_pipe_internalize_label(intlabel, buffer);
if (error == 0) {
pipe = fp->f_data;
PIPE_LOCK(pipe);
error = mac_pipe_label_set(td->td_ucred,
pipe->pipe_pair, intlabel);
PIPE_UNLOCK(pipe);
}
mac_pipe_label_free(intlabel);
break;
case DTYPE_SOCKET:
if (!(mac_labeled & MPC_OBJECT_SOCKET)) {
error = EINVAL;
goto out_fdrop;
}
intlabel = mac_socket_label_alloc(M_WAITOK);
error = mac_socket_internalize_label(intlabel, buffer);
if (error == 0) {
so = fp->f_data;
error = mac_socket_label_set(td->td_ucred, so,
intlabel);
}
mac_socket_label_free(intlabel);
break;
default:
error = EINVAL;
}
out_fdrop:
fdrop(fp, td);
out:
free(buffer, M_MACTEMP);
return (error);
}
int
sys___mac_set_file(struct thread *td, struct __mac_set_file_args *uap)
{
struct label *intlabel;
struct nameidata nd;
struct mount *mp;
struct mac mac;
char *buffer;
int error;
if (!(mac_labeled & MPC_OBJECT_VNODE))
return (EINVAL);
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
intlabel = mac_vnode_label_alloc();
error = mac_vnode_internalize_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error)
goto out;
NDINIT(&nd, LOOKUP, LOCKLEAF | FOLLOW, UIO_USERSPACE,
uap->path_p, td);
error = namei(&nd);
if (error == 0) {
error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH);
if (error == 0) {
error = vn_setlabel(nd.ni_vp, intlabel,
td->td_ucred);
vn_finished_write(mp);
}
}
NDFREE(&nd, 0);
out:
mac_vnode_label_free(intlabel);
return (error);
}
int
sys___mac_set_link(struct thread *td, struct __mac_set_link_args *uap)
{
struct label *intlabel;
struct nameidata nd;
struct mount *mp;
struct mac mac;
char *buffer;
int error;
if (!(mac_labeled & MPC_OBJECT_VNODE))
return (EINVAL);
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
intlabel = mac_vnode_label_alloc();
error = mac_vnode_internalize_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error)
goto out;
NDINIT(&nd, LOOKUP, LOCKLEAF | NOFOLLOW, UIO_USERSPACE,
uap->path_p, td);
error = namei(&nd);
if (error == 0) {
error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH);
if (error == 0) {
error = vn_setlabel(nd.ni_vp, intlabel,
td->td_ucred);
vn_finished_write(mp);
}
}
NDFREE(&nd, 0);
out:
mac_vnode_label_free(intlabel);
return (error);
}
int
sys_mac_syscall(struct thread *td, struct mac_syscall_args *uap)
{
struct mac_policy_conf *mpc;
char target[MAC_MAX_POLICY_NAME];
int error;
error = copyinstr(uap->policy, target, sizeof(target), NULL);
if (error)
return (error);
error = ENOSYS;
LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {
if (strcmp(mpc->mpc_name, target) == 0 &&
mpc->mpc_ops->mpo_syscall != NULL) {
error = mpc->mpc_ops->mpo_syscall(td,
uap->call, uap->arg);
goto out;
}
}
if (!LIST_EMPTY(&mac_policy_list)) {
mac_policy_slock_sleep();
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {
if (strcmp(mpc->mpc_name, target) == 0 &&
mpc->mpc_ops->mpo_syscall != NULL) {
error = mpc->mpc_ops->mpo_syscall(td,
uap->call, uap->arg);
break;
}
}
mac_policy_sunlock_sleep();
}
out:
return (error);
}
#else /* !MAC */
int
sys___mac_get_pid(struct thread *td, struct __mac_get_pid_args *uap)
{
return (ENOSYS);
}
int
sys___mac_get_proc(struct thread *td, struct __mac_get_proc_args *uap)
{
return (ENOSYS);
}
int
sys___mac_set_proc(struct thread *td, struct __mac_set_proc_args *uap)
{
return (ENOSYS);
}
int
sys___mac_get_fd(struct thread *td, struct __mac_get_fd_args *uap)
{
return (ENOSYS);
}
int
sys___mac_get_file(struct thread *td, struct __mac_get_file_args *uap)
{
return (ENOSYS);
}
int
sys___mac_get_link(struct thread *td, struct __mac_get_link_args *uap)
{
return (ENOSYS);
}
int
sys___mac_set_fd(struct thread *td, struct __mac_set_fd_args *uap)
{
return (ENOSYS);
}
int
sys___mac_set_file(struct thread *td, struct __mac_set_file_args *uap)
{
return (ENOSYS);
}
int
sys___mac_set_link(struct thread *td, struct __mac_set_link_args *uap)
{
return (ENOSYS);
}
int
sys_mac_syscall(struct thread *td, struct mac_syscall_args *uap)
{
return (ENOSYS);
}
#endif /* !MAC */