linux/security/selinux/selinuxfs.c
Stephen Smalley c6d3aaa4e3 selinux: dynamic class/perm discovery
Modify SELinux to dynamically discover class and permission values
upon policy load, based on the dynamic object class/perm discovery
logic from libselinux.  A mapping is created between kernel-private
class and permission indices used outside the security server and the
policy values used within the security server.

The mappings are only applied upon kernel-internal computations;
similar mappings for the private indices of userspace object managers
is handled on a per-object manager basis by the userspace AVC.  The
interfaces for compute_av and transition_sid are split for kernel
vs. userspace; the userspace functions are distinguished by a _user
suffix.

The kernel-private class indices are no longer tied to the policy
values and thus do not need to skip indices for userspace classes;
thus the kernel class index values are compressed.  The flask.h
definitions were regenerated by deleting the userspace classes from
refpolicy's definitions and then regenerating the headers.  Going
forward, we can just maintain the flask.h, av_permissions.h, and
classmap.h definitions separately from policy as they are no longer
tied to the policy values.  The next patch introduces a utility to
automate generation of flask.h and av_permissions.h from the
classmap.h definitions.

The older kernel class and permission string tables are removed and
replaced by a single security class mapping table that is walked at
policy load to generate the mapping.  The old kernel class validation
logic is completely replaced by the mapping logic.

The handle unknown logic is reworked.  reject_unknown=1 is handled
when the mappings are computed at policy load time, similar to the old
handling by the class validation logic.  allow_unknown=1 is handled
when computing and mapping decisions - if the permission was not able
to be mapped (i.e. undefined, mapped to zero), then it is
automatically added to the allowed vector.  If the class was not able
to be mapped (i.e. undefined, mapped to zero), then all permissions
are allowed for it if allow_unknown=1.

avc_audit leverages the new security class mapping table to lookup the
class and permission names from the kernel-private indices.

The mdp program is updated to use the new table when generating the
class definitions and allow rules for a minimal boot policy for the
kernel.  It should be noted that this policy will not include any
userspace classes, nor will its policy index values for the kernel
classes correspond with the ones in refpolicy (they will instead match
the kernel-private indices).

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-10-07 21:56:42 +11:00

1741 lines
38 KiB
C

/* Updated: Karl MacMillan <kmacmillan@tresys.com>
*
* Added conditional policy language extensions
*
* Updated: Hewlett-Packard <paul.moore@hp.com>
*
* Added support for the policy capability bitmap
*
* Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
* Copyright (C) 2003 - 2004 Tresys Technology, LLC
* Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2.
*/
#include <linux/kernel.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/security.h>
#include <linux/major.h>
#include <linux/seq_file.h>
#include <linux/percpu.h>
#include <linux/audit.h>
#include <linux/uaccess.h>
/* selinuxfs pseudo filesystem for exporting the security policy API.
Based on the proc code and the fs/nfsd/nfsctl.c code. */
#include "flask.h"
#include "avc.h"
#include "avc_ss.h"
#include "security.h"
#include "objsec.h"
#include "conditional.h"
/* Policy capability filenames */
static char *policycap_names[] = {
"network_peer_controls",
"open_perms"
};
unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
static int __init checkreqprot_setup(char *str)
{
unsigned long checkreqprot;
if (!strict_strtoul(str, 0, &checkreqprot))
selinux_checkreqprot = checkreqprot ? 1 : 0;
return 1;
}
__setup("checkreqprot=", checkreqprot_setup);
static DEFINE_MUTEX(sel_mutex);
/* global data for booleans */
static struct dentry *bool_dir;
static int bool_num;
static char **bool_pending_names;
static int *bool_pending_values;
/* global data for classes */
static struct dentry *class_dir;
static unsigned long last_class_ino;
/* global data for policy capabilities */
static struct dentry *policycap_dir;
extern void selnl_notify_setenforce(int val);
/* Check whether a task is allowed to use a security operation. */
static int task_has_security(struct task_struct *tsk,
u32 perms)
{
const struct task_security_struct *tsec;
u32 sid = 0;
rcu_read_lock();
tsec = __task_cred(tsk)->security;
if (tsec)
sid = tsec->sid;
rcu_read_unlock();
if (!tsec)
return -EACCES;
return avc_has_perm(sid, SECINITSID_SECURITY,
SECCLASS_SECURITY, perms, NULL);
}
enum sel_inos {
SEL_ROOT_INO = 2,
SEL_LOAD, /* load policy */
SEL_ENFORCE, /* get or set enforcing status */
SEL_CONTEXT, /* validate context */
SEL_ACCESS, /* compute access decision */
SEL_CREATE, /* compute create labeling decision */
SEL_RELABEL, /* compute relabeling decision */
SEL_USER, /* compute reachable user contexts */
SEL_POLICYVERS, /* return policy version for this kernel */
SEL_COMMIT_BOOLS, /* commit new boolean values */
SEL_MLS, /* return if MLS policy is enabled */
SEL_DISABLE, /* disable SELinux until next reboot */
SEL_MEMBER, /* compute polyinstantiation membership decision */
SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
SEL_COMPAT_NET, /* whether to use old compat network packet controls */
SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
SEL_INO_NEXT, /* The next inode number to use */
};
static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
#define SEL_INITCON_INO_OFFSET 0x01000000
#define SEL_BOOL_INO_OFFSET 0x02000000
#define SEL_CLASS_INO_OFFSET 0x04000000
#define SEL_POLICYCAP_INO_OFFSET 0x08000000
#define SEL_INO_MASK 0x00ffffff
#define TMPBUFLEN 12
static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char tmpbuf[TMPBUFLEN];
ssize_t length;
length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char *page;
ssize_t length;
int new_value;
if (count >= PAGE_SIZE)
return -ENOMEM;
if (*ppos != 0) {
/* No partial writes. */
return -EINVAL;
}
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
length = -EINVAL;
if (sscanf(page, "%d", &new_value) != 1)
goto out;
if (new_value != selinux_enforcing) {
length = task_has_security(current, SECURITY__SETENFORCE);
if (length)
goto out;
audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
"enforcing=%d old_enforcing=%d auid=%u ses=%u",
new_value, selinux_enforcing,
audit_get_loginuid(current),
audit_get_sessionid(current));
selinux_enforcing = new_value;
if (selinux_enforcing)
avc_ss_reset(0);
selnl_notify_setenforce(selinux_enforcing);
}
length = count;
out:
free_page((unsigned long) page);
return length;
}
#else
#define sel_write_enforce NULL
#endif
static const struct file_operations sel_enforce_ops = {
.read = sel_read_enforce,
.write = sel_write_enforce,
};
static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char tmpbuf[TMPBUFLEN];
ssize_t length;
ino_t ino = filp->f_path.dentry->d_inode->i_ino;
int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
security_get_reject_unknown() : !security_get_allow_unknown();
length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static const struct file_operations sel_handle_unknown_ops = {
.read = sel_read_handle_unknown,
};
#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static ssize_t sel_write_disable(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char *page;
ssize_t length;
int new_value;
extern int selinux_disable(void);
if (count >= PAGE_SIZE)
return -ENOMEM;
if (*ppos != 0) {
/* No partial writes. */
return -EINVAL;
}
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
length = -EINVAL;
if (sscanf(page, "%d", &new_value) != 1)
goto out;
if (new_value) {
length = selinux_disable();
if (length < 0)
goto out;
audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
"selinux=0 auid=%u ses=%u",
audit_get_loginuid(current),
audit_get_sessionid(current));
}
length = count;
out:
free_page((unsigned long) page);
return length;
}
#else
#define sel_write_disable NULL
#endif
static const struct file_operations sel_disable_ops = {
.write = sel_write_disable,
};
static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char tmpbuf[TMPBUFLEN];
ssize_t length;
length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static const struct file_operations sel_policyvers_ops = {
.read = sel_read_policyvers,
};
/* declaration for sel_write_load */
static int sel_make_bools(void);
static int sel_make_classes(void);
static int sel_make_policycap(void);
/* declaration for sel_make_class_dirs */
static int sel_make_dir(struct inode *dir, struct dentry *dentry,
unsigned long *ino);
static ssize_t sel_read_mls(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char tmpbuf[TMPBUFLEN];
ssize_t length;
length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_mls_enabled);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static const struct file_operations sel_mls_ops = {
.read = sel_read_mls,
};
static ssize_t sel_write_load(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int ret;
ssize_t length;
void *data = NULL;
mutex_lock(&sel_mutex);
length = task_has_security(current, SECURITY__LOAD_POLICY);
if (length)
goto out;
if (*ppos != 0) {
/* No partial writes. */
length = -EINVAL;
goto out;
}
if ((count > 64 * 1024 * 1024)
|| (data = vmalloc(count)) == NULL) {
length = -ENOMEM;
goto out;
}
length = -EFAULT;
if (copy_from_user(data, buf, count) != 0)
goto out;
length = security_load_policy(data, count);
if (length)
goto out;
ret = sel_make_bools();
if (ret) {
length = ret;
goto out1;
}
ret = sel_make_classes();
if (ret) {
length = ret;
goto out1;
}
ret = sel_make_policycap();
if (ret)
length = ret;
else
length = count;
out1:
audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
"policy loaded auid=%u ses=%u",
audit_get_loginuid(current),
audit_get_sessionid(current));
out:
mutex_unlock(&sel_mutex);
vfree(data);
return length;
}
static const struct file_operations sel_load_ops = {
.write = sel_write_load,
};
static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
{
char *canon;
u32 sid, len;
ssize_t length;
length = task_has_security(current, SECURITY__CHECK_CONTEXT);
if (length)
return length;
length = security_context_to_sid(buf, size, &sid);
if (length < 0)
return length;
length = security_sid_to_context(sid, &canon, &len);
if (length < 0)
return length;
if (len > SIMPLE_TRANSACTION_LIMIT) {
printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
"payload max\n", __func__, len);
length = -ERANGE;
goto out;
}
memcpy(buf, canon, len);
length = len;
out:
kfree(canon);
return length;
}
static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char tmpbuf[TMPBUFLEN];
ssize_t length;
length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char *page;
ssize_t length;
unsigned int new_value;
length = task_has_security(current, SECURITY__SETCHECKREQPROT);
if (length)
return length;
if (count >= PAGE_SIZE)
return -ENOMEM;
if (*ppos != 0) {
/* No partial writes. */
return -EINVAL;
}
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
length = -EINVAL;
if (sscanf(page, "%u", &new_value) != 1)
goto out;
selinux_checkreqprot = new_value ? 1 : 0;
length = count;
out:
free_page((unsigned long) page);
return length;
}
static const struct file_operations sel_checkreqprot_ops = {
.read = sel_read_checkreqprot,
.write = sel_write_checkreqprot,
};
/*
* Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
*/
static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
static ssize_t (*write_op[])(struct file *, char *, size_t) = {
[SEL_ACCESS] = sel_write_access,
[SEL_CREATE] = sel_write_create,
[SEL_RELABEL] = sel_write_relabel,
[SEL_USER] = sel_write_user,
[SEL_MEMBER] = sel_write_member,
[SEL_CONTEXT] = sel_write_context,
};
static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
{
ino_t ino = file->f_path.dentry->d_inode->i_ino;
char *data;
ssize_t rv;
if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
return -EINVAL;
data = simple_transaction_get(file, buf, size);
if (IS_ERR(data))
return PTR_ERR(data);
rv = write_op[ino](file, data, size);
if (rv > 0) {
simple_transaction_set(file, rv);
rv = size;
}
return rv;
}
static const struct file_operations transaction_ops = {
.write = selinux_transaction_write,
.read = simple_transaction_read,
.release = simple_transaction_release,
};
/*
* payload - write methods
* If the method has a response, the response should be put in buf,
* and the length returned. Otherwise return 0 or and -error.
*/
static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
{
char *scon, *tcon;
u32 ssid, tsid;
u16 tclass;
u32 req;
struct av_decision avd;
ssize_t length;
length = task_has_security(current, SECURITY__COMPUTE_AV);
if (length)
return length;
length = -ENOMEM;
scon = kzalloc(size+1, GFP_KERNEL);
if (!scon)
return length;
tcon = kzalloc(size+1, GFP_KERNEL);
if (!tcon)
goto out;
length = -EINVAL;
if (sscanf(buf, "%s %s %hu %x", scon, tcon, &tclass, &req) != 4)
goto out2;
length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
if (length < 0)
goto out2;
length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
if (length < 0)
goto out2;
length = security_compute_av_user(ssid, tsid, tclass, req, &avd);
if (length < 0)
goto out2;
length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
"%x %x %x %x %u %x",
avd.allowed, 0xffffffff,
avd.auditallow, avd.auditdeny,
avd.seqno, avd.flags);
out2:
kfree(tcon);
out:
kfree(scon);
return length;
}
static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
{
char *scon, *tcon;
u32 ssid, tsid, newsid;
u16 tclass;
ssize_t length;
char *newcon;
u32 len;
length = task_has_security(current, SECURITY__COMPUTE_CREATE);
if (length)
return length;
length = -ENOMEM;
scon = kzalloc(size+1, GFP_KERNEL);
if (!scon)
return length;
tcon = kzalloc(size+1, GFP_KERNEL);
if (!tcon)
goto out;
length = -EINVAL;
if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
goto out2;
length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
if (length < 0)
goto out2;
length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
if (length < 0)
goto out2;
length = security_transition_sid_user(ssid, tsid, tclass, &newsid);
if (length < 0)
goto out2;
length = security_sid_to_context(newsid, &newcon, &len);
if (length < 0)
goto out2;
if (len > SIMPLE_TRANSACTION_LIMIT) {
printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
"payload max\n", __func__, len);
length = -ERANGE;
goto out3;
}
memcpy(buf, newcon, len);
length = len;
out3:
kfree(newcon);
out2:
kfree(tcon);
out:
kfree(scon);
return length;
}
static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
{
char *scon, *tcon;
u32 ssid, tsid, newsid;
u16 tclass;
ssize_t length;
char *newcon;
u32 len;
length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
if (length)
return length;
length = -ENOMEM;
scon = kzalloc(size+1, GFP_KERNEL);
if (!scon)
return length;
tcon = kzalloc(size+1, GFP_KERNEL);
if (!tcon)
goto out;
length = -EINVAL;
if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
goto out2;
length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
if (length < 0)
goto out2;
length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
if (length < 0)
goto out2;
length = security_change_sid(ssid, tsid, tclass, &newsid);
if (length < 0)
goto out2;
length = security_sid_to_context(newsid, &newcon, &len);
if (length < 0)
goto out2;
if (len > SIMPLE_TRANSACTION_LIMIT) {
length = -ERANGE;
goto out3;
}
memcpy(buf, newcon, len);
length = len;
out3:
kfree(newcon);
out2:
kfree(tcon);
out:
kfree(scon);
return length;
}
static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
{
char *con, *user, *ptr;
u32 sid, *sids;
ssize_t length;
char *newcon;
int i, rc;
u32 len, nsids;
length = task_has_security(current, SECURITY__COMPUTE_USER);
if (length)
return length;
length = -ENOMEM;
con = kzalloc(size+1, GFP_KERNEL);
if (!con)
return length;
user = kzalloc(size+1, GFP_KERNEL);
if (!user)
goto out;
length = -EINVAL;
if (sscanf(buf, "%s %s", con, user) != 2)
goto out2;
length = security_context_to_sid(con, strlen(con)+1, &sid);
if (length < 0)
goto out2;
length = security_get_user_sids(sid, user, &sids, &nsids);
if (length < 0)
goto out2;
length = sprintf(buf, "%u", nsids) + 1;
ptr = buf + length;
for (i = 0; i < nsids; i++) {
rc = security_sid_to_context(sids[i], &newcon, &len);
if (rc) {
length = rc;
goto out3;
}
if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
kfree(newcon);
length = -ERANGE;
goto out3;
}
memcpy(ptr, newcon, len);
kfree(newcon);
ptr += len;
length += len;
}
out3:
kfree(sids);
out2:
kfree(user);
out:
kfree(con);
return length;
}
static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
{
char *scon, *tcon;
u32 ssid, tsid, newsid;
u16 tclass;
ssize_t length;
char *newcon;
u32 len;
length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
if (length)
return length;
length = -ENOMEM;
scon = kzalloc(size+1, GFP_KERNEL);
if (!scon)
return length;
tcon = kzalloc(size+1, GFP_KERNEL);
if (!tcon)
goto out;
length = -EINVAL;
if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
goto out2;
length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
if (length < 0)
goto out2;
length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
if (length < 0)
goto out2;
length = security_member_sid(ssid, tsid, tclass, &newsid);
if (length < 0)
goto out2;
length = security_sid_to_context(newsid, &newcon, &len);
if (length < 0)
goto out2;
if (len > SIMPLE_TRANSACTION_LIMIT) {
printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
"payload max\n", __func__, len);
length = -ERANGE;
goto out3;
}
memcpy(buf, newcon, len);
length = len;
out3:
kfree(newcon);
out2:
kfree(tcon);
out:
kfree(scon);
return length;
}
static struct inode *sel_make_inode(struct super_block *sb, int mode)
{
struct inode *ret = new_inode(sb);
if (ret) {
ret->i_mode = mode;
ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
}
return ret;
}
static ssize_t sel_read_bool(struct file *filep, char __user *buf,
size_t count, loff_t *ppos)
{
char *page = NULL;
ssize_t length;
ssize_t ret;
int cur_enforcing;
struct inode *inode = filep->f_path.dentry->d_inode;
unsigned index = inode->i_ino & SEL_INO_MASK;
const char *name = filep->f_path.dentry->d_name.name;
mutex_lock(&sel_mutex);
if (index >= bool_num || strcmp(name, bool_pending_names[index])) {
ret = -EINVAL;
goto out;
}
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page) {
ret = -ENOMEM;
goto out;
}
cur_enforcing = security_get_bool_value(index);
if (cur_enforcing < 0) {
ret = cur_enforcing;
goto out;
}
length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
bool_pending_values[index]);
ret = simple_read_from_buffer(buf, count, ppos, page, length);
out:
mutex_unlock(&sel_mutex);
if (page)
free_page((unsigned long)page);
return ret;
}
static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
size_t count, loff_t *ppos)
{
char *page = NULL;
ssize_t length;
int new_value;
struct inode *inode = filep->f_path.dentry->d_inode;
unsigned index = inode->i_ino & SEL_INO_MASK;
const char *name = filep->f_path.dentry->d_name.name;
mutex_lock(&sel_mutex);
length = task_has_security(current, SECURITY__SETBOOL);
if (length)
goto out;
if (index >= bool_num || strcmp(name, bool_pending_names[index])) {
length = -EINVAL;
goto out;
}
if (count >= PAGE_SIZE) {
length = -ENOMEM;
goto out;
}
if (*ppos != 0) {
/* No partial writes. */
length = -EINVAL;
goto out;
}
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page) {
length = -ENOMEM;
goto out;
}
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
length = -EINVAL;
if (sscanf(page, "%d", &new_value) != 1)
goto out;
if (new_value)
new_value = 1;
bool_pending_values[index] = new_value;
length = count;
out:
mutex_unlock(&sel_mutex);
if (page)
free_page((unsigned long) page);
return length;
}
static const struct file_operations sel_bool_ops = {
.read = sel_read_bool,
.write = sel_write_bool,
};
static ssize_t sel_commit_bools_write(struct file *filep,
const char __user *buf,
size_t count, loff_t *ppos)
{
char *page = NULL;
ssize_t length;
int new_value;
mutex_lock(&sel_mutex);
length = task_has_security(current, SECURITY__SETBOOL);
if (length)
goto out;
if (count >= PAGE_SIZE) {
length = -ENOMEM;
goto out;
}
if (*ppos != 0) {
/* No partial writes. */
goto out;
}
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page) {
length = -ENOMEM;
goto out;
}
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
length = -EINVAL;
if (sscanf(page, "%d", &new_value) != 1)
goto out;
if (new_value && bool_pending_values)
security_set_bools(bool_num, bool_pending_values);
length = count;
out:
mutex_unlock(&sel_mutex);
if (page)
free_page((unsigned long) page);
return length;
}
static const struct file_operations sel_commit_bools_ops = {
.write = sel_commit_bools_write,
};
static void sel_remove_entries(struct dentry *de)
{
struct list_head *node;
spin_lock(&dcache_lock);
node = de->d_subdirs.next;
while (node != &de->d_subdirs) {
struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
list_del_init(node);
if (d->d_inode) {
d = dget_locked(d);
spin_unlock(&dcache_lock);
d_delete(d);
simple_unlink(de->d_inode, d);
dput(d);
spin_lock(&dcache_lock);
}
node = de->d_subdirs.next;
}
spin_unlock(&dcache_lock);
}
#define BOOL_DIR_NAME "booleans"
static int sel_make_bools(void)
{
int i, ret = 0;
ssize_t len;
struct dentry *dentry = NULL;
struct dentry *dir = bool_dir;
struct inode *inode = NULL;
struct inode_security_struct *isec;
char **names = NULL, *page;
int num;
int *values = NULL;
u32 sid;
/* remove any existing files */
kfree(bool_pending_names);
kfree(bool_pending_values);
bool_pending_names = NULL;
bool_pending_values = NULL;
sel_remove_entries(dir);
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
ret = security_get_bools(&num, &names, &values);
if (ret != 0)
goto out;
for (i = 0; i < num; i++) {
dentry = d_alloc_name(dir, names[i]);
if (!dentry) {
ret = -ENOMEM;
goto err;
}
inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
if (!inode) {
ret = -ENOMEM;
goto err;
}
len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
if (len < 0) {
ret = -EINVAL;
goto err;
} else if (len >= PAGE_SIZE) {
ret = -ENAMETOOLONG;
goto err;
}
isec = (struct inode_security_struct *)inode->i_security;
ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
if (ret)
goto err;
isec->sid = sid;
isec->initialized = 1;
inode->i_fop = &sel_bool_ops;
inode->i_ino = i|SEL_BOOL_INO_OFFSET;
d_add(dentry, inode);
}
bool_num = num;
bool_pending_names = names;
bool_pending_values = values;
out:
free_page((unsigned long)page);
return ret;
err:
if (names) {
for (i = 0; i < num; i++)
kfree(names[i]);
kfree(names);
}
kfree(values);
sel_remove_entries(dir);
ret = -ENOMEM;
goto out;
}
#define NULL_FILE_NAME "null"
struct dentry *selinux_null;
static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char tmpbuf[TMPBUFLEN];
ssize_t length;
length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static ssize_t sel_write_avc_cache_threshold(struct file *file,
const char __user *buf,
size_t count, loff_t *ppos)
{
char *page;
ssize_t ret;
int new_value;
if (count >= PAGE_SIZE) {
ret = -ENOMEM;
goto out;
}
if (*ppos != 0) {
/* No partial writes. */
ret = -EINVAL;
goto out;
}
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page) {
ret = -ENOMEM;
goto out;
}
if (copy_from_user(page, buf, count)) {
ret = -EFAULT;
goto out_free;
}
if (sscanf(page, "%u", &new_value) != 1) {
ret = -EINVAL;
goto out;
}
if (new_value != avc_cache_threshold) {
ret = task_has_security(current, SECURITY__SETSECPARAM);
if (ret)
goto out_free;
avc_cache_threshold = new_value;
}
ret = count;
out_free:
free_page((unsigned long)page);
out:
return ret;
}
static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
char *page;
ssize_t ret = 0;
page = (char *)__get_free_page(GFP_KERNEL);
if (!page) {
ret = -ENOMEM;
goto out;
}
ret = avc_get_hash_stats(page);
if (ret >= 0)
ret = simple_read_from_buffer(buf, count, ppos, page, ret);
free_page((unsigned long)page);
out:
return ret;
}
static const struct file_operations sel_avc_cache_threshold_ops = {
.read = sel_read_avc_cache_threshold,
.write = sel_write_avc_cache_threshold,
};
static const struct file_operations sel_avc_hash_stats_ops = {
.read = sel_read_avc_hash_stats,
};
#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
{
int cpu;
for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
if (!cpu_possible(cpu))
continue;
*idx = cpu + 1;
return &per_cpu(avc_cache_stats, cpu);
}
return NULL;
}
static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
{
loff_t n = *pos - 1;
if (*pos == 0)
return SEQ_START_TOKEN;
return sel_avc_get_stat_idx(&n);
}
static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
return sel_avc_get_stat_idx(pos);
}
static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
{
struct avc_cache_stats *st = v;
if (v == SEQ_START_TOKEN)
seq_printf(seq, "lookups hits misses allocations reclaims "
"frees\n");
else
seq_printf(seq, "%u %u %u %u %u %u\n", st->lookups,
st->hits, st->misses, st->allocations,
st->reclaims, st->frees);
return 0;
}
static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
{ }
static const struct seq_operations sel_avc_cache_stats_seq_ops = {
.start = sel_avc_stats_seq_start,
.next = sel_avc_stats_seq_next,
.show = sel_avc_stats_seq_show,
.stop = sel_avc_stats_seq_stop,
};
static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
{
return seq_open(file, &sel_avc_cache_stats_seq_ops);
}
static const struct file_operations sel_avc_cache_stats_ops = {
.open = sel_open_avc_cache_stats,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
#endif
static int sel_make_avc_files(struct dentry *dir)
{
int i, ret = 0;
static struct tree_descr files[] = {
{ "cache_threshold",
&sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
{ "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
{ "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
#endif
};
for (i = 0; i < ARRAY_SIZE(files); i++) {
struct inode *inode;
struct dentry *dentry;
dentry = d_alloc_name(dir, files[i].name);
if (!dentry) {
ret = -ENOMEM;
goto out;
}
inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
if (!inode) {
ret = -ENOMEM;
goto out;
}
inode->i_fop = files[i].ops;
inode->i_ino = ++sel_last_ino;
d_add(dentry, inode);
}
out:
return ret;
}
static ssize_t sel_read_initcon(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct inode *inode;
char *con;
u32 sid, len;
ssize_t ret;
inode = file->f_path.dentry->d_inode;
sid = inode->i_ino&SEL_INO_MASK;
ret = security_sid_to_context(sid, &con, &len);
if (ret < 0)
return ret;
ret = simple_read_from_buffer(buf, count, ppos, con, len);
kfree(con);
return ret;
}
static const struct file_operations sel_initcon_ops = {
.read = sel_read_initcon,
};
static int sel_make_initcon_files(struct dentry *dir)
{
int i, ret = 0;
for (i = 1; i <= SECINITSID_NUM; i++) {
struct inode *inode;
struct dentry *dentry;
dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
if (!dentry) {
ret = -ENOMEM;
goto out;
}
inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
if (!inode) {
ret = -ENOMEM;
goto out;
}
inode->i_fop = &sel_initcon_ops;
inode->i_ino = i|SEL_INITCON_INO_OFFSET;
d_add(dentry, inode);
}
out:
return ret;
}
static inline unsigned int sel_div(unsigned long a, unsigned long b)
{
return a / b - (a % b < 0);
}
static inline unsigned long sel_class_to_ino(u16 class)
{
return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
}
static inline u16 sel_ino_to_class(unsigned long ino)
{
return sel_div(ino & SEL_INO_MASK, SEL_VEC_MAX + 1);
}
static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
{
return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
}
static inline u32 sel_ino_to_perm(unsigned long ino)
{
return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
}
static ssize_t sel_read_class(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t rc, len;
char *page;
unsigned long ino = file->f_path.dentry->d_inode->i_ino;
page = (char *)__get_free_page(GFP_KERNEL);
if (!page) {
rc = -ENOMEM;
goto out;
}
len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_class(ino));
rc = simple_read_from_buffer(buf, count, ppos, page, len);
free_page((unsigned long)page);
out:
return rc;
}
static const struct file_operations sel_class_ops = {
.read = sel_read_class,
};
static ssize_t sel_read_perm(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t rc, len;
char *page;
unsigned long ino = file->f_path.dentry->d_inode->i_ino;
page = (char *)__get_free_page(GFP_KERNEL);
if (!page) {
rc = -ENOMEM;
goto out;
}
len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_perm(ino));
rc = simple_read_from_buffer(buf, count, ppos, page, len);
free_page((unsigned long)page);
out:
return rc;
}
static const struct file_operations sel_perm_ops = {
.read = sel_read_perm,
};
static ssize_t sel_read_policycap(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
int value;
char tmpbuf[TMPBUFLEN];
ssize_t length;
unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
value = security_policycap_supported(i_ino & SEL_INO_MASK);
length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
static const struct file_operations sel_policycap_ops = {
.read = sel_read_policycap,
};
static int sel_make_perm_files(char *objclass, int classvalue,
struct dentry *dir)
{
int i, rc = 0, nperms;
char **perms;
rc = security_get_permissions(objclass, &perms, &nperms);
if (rc)
goto out;
for (i = 0; i < nperms; i++) {
struct inode *inode;
struct dentry *dentry;
dentry = d_alloc_name(dir, perms[i]);
if (!dentry) {
rc = -ENOMEM;
goto out1;
}
inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
if (!inode) {
rc = -ENOMEM;
goto out1;
}
inode->i_fop = &sel_perm_ops;
/* i+1 since perm values are 1-indexed */
inode->i_ino = sel_perm_to_ino(classvalue, i+1);
d_add(dentry, inode);
}
out1:
for (i = 0; i < nperms; i++)
kfree(perms[i]);
kfree(perms);
out:
return rc;
}
static int sel_make_class_dir_entries(char *classname, int index,
struct dentry *dir)
{
struct dentry *dentry = NULL;
struct inode *inode = NULL;
int rc;
dentry = d_alloc_name(dir, "index");
if (!dentry) {
rc = -ENOMEM;
goto out;
}
inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
if (!inode) {
rc = -ENOMEM;
goto out;
}
inode->i_fop = &sel_class_ops;
inode->i_ino = sel_class_to_ino(index);
d_add(dentry, inode);
dentry = d_alloc_name(dir, "perms");
if (!dentry) {
rc = -ENOMEM;
goto out;
}
rc = sel_make_dir(dir->d_inode, dentry, &last_class_ino);
if (rc)
goto out;
rc = sel_make_perm_files(classname, index, dentry);
out:
return rc;
}
static void sel_remove_classes(void)
{
struct list_head *class_node;
list_for_each(class_node, &class_dir->d_subdirs) {
struct dentry *class_subdir = list_entry(class_node,
struct dentry, d_u.d_child);
struct list_head *class_subdir_node;
list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
struct dentry *d = list_entry(class_subdir_node,
struct dentry, d_u.d_child);
if (d->d_inode)
if (d->d_inode->i_mode & S_IFDIR)
sel_remove_entries(d);
}
sel_remove_entries(class_subdir);
}
sel_remove_entries(class_dir);
}
static int sel_make_classes(void)
{
int rc = 0, nclasses, i;
char **classes;
/* delete any existing entries */
sel_remove_classes();
rc = security_get_classes(&classes, &nclasses);
if (rc < 0)
goto out;
/* +2 since classes are 1-indexed */
last_class_ino = sel_class_to_ino(nclasses+2);
for (i = 0; i < nclasses; i++) {
struct dentry *class_name_dir;
class_name_dir = d_alloc_name(class_dir, classes[i]);
if (!class_name_dir) {
rc = -ENOMEM;
goto out1;
}
rc = sel_make_dir(class_dir->d_inode, class_name_dir,
&last_class_ino);
if (rc)
goto out1;
/* i+1 since class values are 1-indexed */
rc = sel_make_class_dir_entries(classes[i], i+1,
class_name_dir);
if (rc)
goto out1;
}
out1:
for (i = 0; i < nclasses; i++)
kfree(classes[i]);
kfree(classes);
out:
return rc;
}
static int sel_make_policycap(void)
{
unsigned int iter;
struct dentry *dentry = NULL;
struct inode *inode = NULL;
sel_remove_entries(policycap_dir);
for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
if (iter < ARRAY_SIZE(policycap_names))
dentry = d_alloc_name(policycap_dir,
policycap_names[iter]);
else
dentry = d_alloc_name(policycap_dir, "unknown");
if (dentry == NULL)
return -ENOMEM;
inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
if (inode == NULL)
return -ENOMEM;
inode->i_fop = &sel_policycap_ops;
inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
d_add(dentry, inode);
}
return 0;
}
static int sel_make_dir(struct inode *dir, struct dentry *dentry,
unsigned long *ino)
{
int ret = 0;
struct inode *inode;
inode = sel_make_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
if (!inode) {
ret = -ENOMEM;
goto out;
}
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_ino = ++(*ino);
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
d_add(dentry, inode);
/* bump link count on parent directory, too */
inc_nlink(dir);
out:
return ret;
}
static int sel_fill_super(struct super_block *sb, void *data, int silent)
{
int ret;
struct dentry *dentry;
struct inode *inode, *root_inode;
struct inode_security_struct *isec;
static struct tree_descr selinux_files[] = {
[SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
[SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
[SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
[SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
[SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
[SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
[SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
[SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
[SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
[SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
[SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
[SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
[SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
[SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
[SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
/* last one */ {""}
};
ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
if (ret)
goto err;
root_inode = sb->s_root->d_inode;
dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
if (!dentry) {
ret = -ENOMEM;
goto err;
}
ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
if (ret)
goto err;
bool_dir = dentry;
dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
if (!dentry) {
ret = -ENOMEM;
goto err;
}
inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
if (!inode) {
ret = -ENOMEM;
goto err;
}
inode->i_ino = ++sel_last_ino;
isec = (struct inode_security_struct *)inode->i_security;
isec->sid = SECINITSID_DEVNULL;
isec->sclass = SECCLASS_CHR_FILE;
isec->initialized = 1;
init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
d_add(dentry, inode);
selinux_null = dentry;
dentry = d_alloc_name(sb->s_root, "avc");
if (!dentry) {
ret = -ENOMEM;
goto err;
}
ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
if (ret)
goto err;
ret = sel_make_avc_files(dentry);
if (ret)
goto err;
dentry = d_alloc_name(sb->s_root, "initial_contexts");
if (!dentry) {
ret = -ENOMEM;
goto err;
}
ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
if (ret)
goto err;
ret = sel_make_initcon_files(dentry);
if (ret)
goto err;
dentry = d_alloc_name(sb->s_root, "class");
if (!dentry) {
ret = -ENOMEM;
goto err;
}
ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
if (ret)
goto err;
class_dir = dentry;
dentry = d_alloc_name(sb->s_root, "policy_capabilities");
if (!dentry) {
ret = -ENOMEM;
goto err;
}
ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
if (ret)
goto err;
policycap_dir = dentry;
out:
return ret;
err:
printk(KERN_ERR "SELinux: %s: failed while creating inodes\n",
__func__);
goto out;
}
static int sel_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
struct vfsmount *mnt)
{
return get_sb_single(fs_type, flags, data, sel_fill_super, mnt);
}
static struct file_system_type sel_fs_type = {
.name = "selinuxfs",
.get_sb = sel_get_sb,
.kill_sb = kill_litter_super,
};
struct vfsmount *selinuxfs_mount;
static int __init init_sel_fs(void)
{
int err;
if (!selinux_enabled)
return 0;
err = register_filesystem(&sel_fs_type);
if (!err) {
selinuxfs_mount = kern_mount(&sel_fs_type);
if (IS_ERR(selinuxfs_mount)) {
printk(KERN_ERR "selinuxfs: could not mount!\n");
err = PTR_ERR(selinuxfs_mount);
selinuxfs_mount = NULL;
}
}
return err;
}
__initcall(init_sel_fs);
#ifdef CONFIG_SECURITY_SELINUX_DISABLE
void exit_sel_fs(void)
{
unregister_filesystem(&sel_fs_type);
}
#endif