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linux/security/selinux/ss/services.c
Paul Moore e9fd729293 selinux: fix all of the W=1 build warnings 
There were a number of places in the code where the function
definition did not match the associated comment block as well
at least one file where the appropriate header files were not
included (missing function declaration/prototype); this patch
fixes all of these issue such that building the SELinux code
with "W=1" is now warning free.

 % make W=1 security/selinux/

Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-10-13 16:31:51 -04:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Implementation of the security services.
*
* Authors : Stephen Smalley, <sds@tycho.nsa.gov>
* James Morris <jmorris@redhat.com>
*
* Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
*
* Support for enhanced MLS infrastructure.
* Support for context based audit filters.
*
* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
*
* Added conditional policy language extensions
*
* Updated: Hewlett-Packard <paul@paul-moore.com>
*
* Added support for NetLabel
* Added support for the policy capability bitmap
*
* Updated: Chad Sellers <csellers@tresys.com>
*
* Added validation of kernel classes and permissions
*
* Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
*
* Added support for bounds domain and audit messaged on masked permissions
*
* Updated: Guido Trentalancia <guido@trentalancia.com>
*
* Added support for runtime switching of the policy type
*
* Copyright (C) 2008, 2009 NEC Corporation
* Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
* Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
* Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
* Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/sched.h>
#include <linux/audit.h>
#include <linux/vmalloc.h>
#include <linux/lsm_hooks.h>
#include <net/netlabel.h>
#include "flask.h"
#include "avc.h"
#include "avc_ss.h"
#include "security.h"
#include "context.h"
#include "policydb.h"
#include "sidtab.h"
#include "services.h"
#include "conditional.h"
#include "mls.h"
#include "objsec.h"
#include "netlabel.h"
#include "xfrm.h"
#include "ebitmap.h"
#include "audit.h"
#include "policycap_names.h"
#include "ima.h"
struct convert_context_args {
struct selinux_state *state;
struct policydb *oldp;
struct policydb *newp;
};
struct selinux_policy_convert_data {
struct convert_context_args args;
struct sidtab_convert_params sidtab_params;
};
/* Forward declaration. */
static int context_struct_to_string(struct policydb *policydb,
struct context *context,
char **scontext,
u32 *scontext_len);
static int sidtab_entry_to_string(struct policydb *policydb,
struct sidtab *sidtab,
struct sidtab_entry *entry,
char **scontext,
u32 *scontext_len);
static void context_struct_compute_av(struct policydb *policydb,
struct context *scontext,
struct context *tcontext,
u16 tclass,
struct av_decision *avd,
struct extended_perms *xperms);
static int selinux_set_mapping(struct policydb *pol,
struct security_class_mapping *map,
struct selinux_map *out_map)
{
u16 i, j;
unsigned k;
bool print_unknown_handle = false;
/* Find number of classes in the input mapping */
if (!map)
return -EINVAL;
i = 0;
while (map[i].name)
i++;
/* Allocate space for the class records, plus one for class zero */
out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
if (!out_map->mapping)
return -ENOMEM;
/* Store the raw class and permission values */
j = 0;
while (map[j].name) {
struct security_class_mapping *p_in = map + (j++);
struct selinux_mapping *p_out = out_map->mapping + j;
/* An empty class string skips ahead */
if (!strcmp(p_in->name, "")) {
p_out->num_perms = 0;
continue;
}
p_out->value = string_to_security_class(pol, p_in->name);
if (!p_out->value) {
pr_info("SELinux: Class %s not defined in policy.\n",
p_in->name);
if (pol->reject_unknown)
goto err;
p_out->num_perms = 0;
print_unknown_handle = true;
continue;
}
k = 0;
while (p_in->perms[k]) {
/* An empty permission string skips ahead */
if (!*p_in->perms[k]) {
k++;
continue;
}
p_out->perms[k] = string_to_av_perm(pol, p_out->value,
p_in->perms[k]);
if (!p_out->perms[k]) {
pr_info("SELinux: Permission %s in class %s not defined in policy.\n",
p_in->perms[k], p_in->name);
if (pol->reject_unknown)
goto err;
print_unknown_handle = true;
}
k++;
}
p_out->num_perms = k;
}
if (print_unknown_handle)
pr_info("SELinux: the above unknown classes and permissions will be %s\n",
pol->allow_unknown ? "allowed" : "denied");
out_map->size = i;
return 0;
err:
kfree(out_map->mapping);
out_map->mapping = NULL;
return -EINVAL;
}
/*
* Get real, policy values from mapped values
*/
static u16 unmap_class(struct selinux_map *map, u16 tclass)
{
if (tclass < map->size)
return map->mapping[tclass].value;
return tclass;
}
/*
* Get kernel value for class from its policy value
*/
static u16 map_class(struct selinux_map *map, u16 pol_value)
{
u16 i;
for (i = 1; i < map->size; i++) {
if (map->mapping[i].value == pol_value)
return i;
}
return SECCLASS_NULL;
}
static void map_decision(struct selinux_map *map,
u16 tclass, struct av_decision *avd,
int allow_unknown)
{
if (tclass < map->size) {
struct selinux_mapping *mapping = &map->mapping[tclass];
unsigned int i, n = mapping->num_perms;
u32 result;
for (i = 0, result = 0; i < n; i++) {
if (avd->allowed & mapping->perms[i])
result |= 1<<i;
if (allow_unknown && !mapping->perms[i])
result |= 1<<i;
}
avd->allowed = result;
for (i = 0, result = 0; i < n; i++)
if (avd->auditallow & mapping->perms[i])
result |= 1<<i;
avd->auditallow = result;
for (i = 0, result = 0; i < n; i++) {
if (avd->auditdeny & mapping->perms[i])
result |= 1<<i;
if (!allow_unknown && !mapping->perms[i])
result |= 1<<i;
}
/*
* In case the kernel has a bug and requests a permission
* between num_perms and the maximum permission number, we
* should audit that denial
*/
for (; i < (sizeof(u32)*8); i++)
result |= 1<<i;
avd->auditdeny = result;
}
}
int security_mls_enabled(struct selinux_state *state)
{
int mls_enabled;
struct selinux_policy *policy;
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
mls_enabled = policy->policydb.mls_enabled;
rcu_read_unlock();
return mls_enabled;
}
/*
* Return the boolean value of a constraint expression
* when it is applied to the specified source and target
* security contexts.
*
* xcontext is a special beast... It is used by the validatetrans rules
* only. For these rules, scontext is the context before the transition,
* tcontext is the context after the transition, and xcontext is the context
* of the process performing the transition. All other callers of
* constraint_expr_eval should pass in NULL for xcontext.
*/
static int constraint_expr_eval(struct policydb *policydb,
struct context *scontext,
struct context *tcontext,
struct context *xcontext,
struct constraint_expr *cexpr)
{
u32 val1, val2;
struct context *c;
struct role_datum *r1, *r2;
struct mls_level *l1, *l2;
struct constraint_expr *e;
int s[CEXPR_MAXDEPTH];
int sp = -1;
for (e = cexpr; e; e = e->next) {
switch (e->expr_type) {
case CEXPR_NOT:
BUG_ON(sp < 0);
s[sp] = !s[sp];
break;
case CEXPR_AND:
BUG_ON(sp < 1);
sp--;
s[sp] &= s[sp + 1];
break;
case CEXPR_OR:
BUG_ON(sp < 1);
sp--;
s[sp] |= s[sp + 1];
break;
case CEXPR_ATTR:
if (sp == (CEXPR_MAXDEPTH - 1))
return 0;
switch (e->attr) {
case CEXPR_USER:
val1 = scontext->user;
val2 = tcontext->user;
break;
case CEXPR_TYPE:
val1 = scontext->type;
val2 = tcontext->type;
break;
case CEXPR_ROLE:
val1 = scontext->role;
val2 = tcontext->role;
r1 = policydb->role_val_to_struct[val1 - 1];
r2 = policydb->role_val_to_struct[val2 - 1];
switch (e->op) {
case CEXPR_DOM:
s[++sp] = ebitmap_get_bit(&r1->dominates,
val2 - 1);
continue;
case CEXPR_DOMBY:
s[++sp] = ebitmap_get_bit(&r2->dominates,
val1 - 1);
continue;
case CEXPR_INCOMP:
s[++sp] = (!ebitmap_get_bit(&r1->dominates,
val2 - 1) &&
!ebitmap_get_bit(&r2->dominates,
val1 - 1));
continue;
default:
break;
}
break;
case CEXPR_L1L2:
l1 = &(scontext->range.level[0]);
l2 = &(tcontext->range.level[0]);
goto mls_ops;
case CEXPR_L1H2:
l1 = &(scontext->range.level[0]);
l2 = &(tcontext->range.level[1]);
goto mls_ops;
case CEXPR_H1L2:
l1 = &(scontext->range.level[1]);
l2 = &(tcontext->range.level[0]);
goto mls_ops;
case CEXPR_H1H2:
l1 = &(scontext->range.level[1]);
l2 = &(tcontext->range.level[1]);
goto mls_ops;
case CEXPR_L1H1:
l1 = &(scontext->range.level[0]);
l2 = &(scontext->range.level[1]);
goto mls_ops;
case CEXPR_L2H2:
l1 = &(tcontext->range.level[0]);
l2 = &(tcontext->range.level[1]);
goto mls_ops;
mls_ops:
switch (e->op) {
case CEXPR_EQ:
s[++sp] = mls_level_eq(l1, l2);
continue;
case CEXPR_NEQ:
s[++sp] = !mls_level_eq(l1, l2);
continue;
case CEXPR_DOM:
s[++sp] = mls_level_dom(l1, l2);
continue;
case CEXPR_DOMBY:
s[++sp] = mls_level_dom(l2, l1);
continue;
case CEXPR_INCOMP:
s[++sp] = mls_level_incomp(l2, l1);
continue;
default:
BUG();
return 0;
}
break;
default:
BUG();
return 0;
}
switch (e->op) {
case CEXPR_EQ:
s[++sp] = (val1 == val2);
break;
case CEXPR_NEQ:
s[++sp] = (val1 != val2);
break;
default:
BUG();
return 0;
}
break;
case CEXPR_NAMES:
if (sp == (CEXPR_MAXDEPTH-1))
return 0;
c = scontext;
if (e->attr & CEXPR_TARGET)
c = tcontext;
else if (e->attr & CEXPR_XTARGET) {
c = xcontext;
if (!c) {
BUG();
return 0;
}
}
if (e->attr & CEXPR_USER)
val1 = c->user;
else if (e->attr & CEXPR_ROLE)
val1 = c->role;
else if (e->attr & CEXPR_TYPE)
val1 = c->type;
else {
BUG();
return 0;
}
switch (e->op) {
case CEXPR_EQ:
s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
break;
case CEXPR_NEQ:
s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
break;
default:
BUG();
return 0;
}
break;
default:
BUG();
return 0;
}
}
BUG_ON(sp != 0);
return s[0];
}
/*
* security_dump_masked_av - dumps masked permissions during
* security_compute_av due to RBAC, MLS/Constraint and Type bounds.
*/
static int dump_masked_av_helper(void *k, void *d, void *args)
{
struct perm_datum *pdatum = d;
char **permission_names = args;
BUG_ON(pdatum->value < 1 || pdatum->value > 32);
permission_names[pdatum->value - 1] = (char *)k;
return 0;
}
static void security_dump_masked_av(struct policydb *policydb,
struct context *scontext,
struct context *tcontext,
u16 tclass,
u32 permissions,
const char *reason)
{
struct common_datum *common_dat;
struct class_datum *tclass_dat;
struct audit_buffer *ab;
char *tclass_name;
char *scontext_name = NULL;
char *tcontext_name = NULL;
char *permission_names[32];
int index;
u32 length;
bool need_comma = false;
if (!permissions)
return;
tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
tclass_dat = policydb->class_val_to_struct[tclass - 1];
common_dat = tclass_dat->comdatum;
/* init permission_names */
if (common_dat &&
hashtab_map(&common_dat->permissions.table,
dump_masked_av_helper, permission_names) < 0)
goto out;
if (hashtab_map(&tclass_dat->permissions.table,
dump_masked_av_helper, permission_names) < 0)
goto out;
/* get scontext/tcontext in text form */
if (context_struct_to_string(policydb, scontext,
&scontext_name, &length) < 0)
goto out;
if (context_struct_to_string(policydb, tcontext,
&tcontext_name, &length) < 0)
goto out;
/* audit a message */
ab = audit_log_start(audit_context(),
GFP_ATOMIC, AUDIT_SELINUX_ERR);
if (!ab)
goto out;
audit_log_format(ab, "op=security_compute_av reason=%s "
"scontext=%s tcontext=%s tclass=%s perms=",
reason, scontext_name, tcontext_name, tclass_name);
for (index = 0; index < 32; index++) {
u32 mask = (1 << index);
if ((mask & permissions) == 0)
continue;
audit_log_format(ab, "%s%s",
need_comma ? "," : "",
permission_names[index]
? permission_names[index] : "????");
need_comma = true;
}
audit_log_end(ab);
out:
/* release scontext/tcontext */
kfree(tcontext_name);
kfree(scontext_name);
return;
}
/*
* security_boundary_permission - drops violated permissions
* on boundary constraint.
*/
static void type_attribute_bounds_av(struct policydb *policydb,
struct context *scontext,
struct context *tcontext,
u16 tclass,
struct av_decision *avd)
{
struct context lo_scontext;
struct context lo_tcontext, *tcontextp = tcontext;
struct av_decision lo_avd;
struct type_datum *source;
struct type_datum *target;
u32 masked = 0;
source = policydb->type_val_to_struct[scontext->type - 1];
BUG_ON(!source);
if (!source->bounds)
return;
target = policydb->type_val_to_struct[tcontext->type - 1];
BUG_ON(!target);
memset(&lo_avd, 0, sizeof(lo_avd));
memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
lo_scontext.type = source->bounds;
if (target->bounds) {
memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
lo_tcontext.type = target->bounds;
tcontextp = &lo_tcontext;
}
context_struct_compute_av(policydb, &lo_scontext,
tcontextp,
tclass,
&lo_avd,
NULL);
masked = ~lo_avd.allowed & avd->allowed;
if (likely(!masked))
return; /* no masked permission */
/* mask violated permissions */
avd->allowed &= ~masked;
/* audit masked permissions */
security_dump_masked_av(policydb, scontext, tcontext,
tclass, masked, "bounds");
}
/*
* flag which drivers have permissions
* only looking for ioctl based extended permssions
*/
void services_compute_xperms_drivers(
struct extended_perms *xperms,
struct avtab_node *node)
{
unsigned int i;
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
/* if one or more driver has all permissions allowed */
for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
/* if allowing permissions within a driver */
security_xperm_set(xperms->drivers.p,
node->datum.u.xperms->driver);
}
xperms->len = 1;
}
/*
* Compute access vectors and extended permissions based on a context
* structure pair for the permissions in a particular class.
*/
static void context_struct_compute_av(struct policydb *policydb,
struct context *scontext,
struct context *tcontext,
u16 tclass,
struct av_decision *avd,
struct extended_perms *xperms)
{
struct constraint_node *constraint;
struct role_allow *ra;
struct avtab_key avkey;
struct avtab_node *node;
struct class_datum *tclass_datum;
struct ebitmap *sattr, *tattr;
struct ebitmap_node *snode, *tnode;
unsigned int i, j;
avd->allowed = 0;
avd->auditallow = 0;
avd->auditdeny = 0xffffffff;
if (xperms) {
memset(&xperms->drivers, 0, sizeof(xperms->drivers));
xperms->len = 0;
}
if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
if (printk_ratelimit())
pr_warn("SELinux: Invalid class %hu\n", tclass);
return;
}
tclass_datum = policydb->class_val_to_struct[tclass - 1];
/*
* If a specific type enforcement rule was defined for
* this permission check, then use it.
*/
avkey.target_class = tclass;
avkey.specified = AVTAB_AV | AVTAB_XPERMS;
sattr = &policydb->type_attr_map_array[scontext->type - 1];
tattr = &policydb->type_attr_map_array[tcontext->type - 1];
ebitmap_for_each_positive_bit(sattr, snode, i) {
ebitmap_for_each_positive_bit(tattr, tnode, j) {
avkey.source_type = i + 1;
avkey.target_type = j + 1;
for (node = avtab_search_node(&policydb->te_avtab,
&avkey);
node;
node = avtab_search_node_next(node, avkey.specified)) {
if (node->key.specified == AVTAB_ALLOWED)
avd->allowed |= node->datum.u.data;
else if (node->key.specified == AVTAB_AUDITALLOW)
avd->auditallow |= node->datum.u.data;
else if (node->key.specified == AVTAB_AUDITDENY)
avd->auditdeny &= node->datum.u.data;
else if (xperms && (node->key.specified & AVTAB_XPERMS))
services_compute_xperms_drivers(xperms, node);
}
/* Check conditional av table for additional permissions */
cond_compute_av(&policydb->te_cond_avtab, &avkey,
avd, xperms);
}
}
/*
* Remove any permissions prohibited by a constraint (this includes
* the MLS policy).
*/
constraint = tclass_datum->constraints;
while (constraint) {
if ((constraint->permissions & (avd->allowed)) &&
!constraint_expr_eval(policydb, scontext, tcontext, NULL,
constraint->expr)) {
avd->allowed &= ~(constraint->permissions);
}
constraint = constraint->next;
}
/*
* If checking process transition permission and the
* role is changing, then check the (current_role, new_role)
* pair.
*/
if (tclass == policydb->process_class &&
(avd->allowed & policydb->process_trans_perms) &&
scontext->role != tcontext->role) {
for (ra = policydb->role_allow; ra; ra = ra->next) {
if (scontext->role == ra->role &&
tcontext->role == ra->new_role)
break;
}
if (!ra)
avd->allowed &= ~policydb->process_trans_perms;
}
/*
* If the given source and target types have boundary
* constraint, lazy checks have to mask any violated
* permission and notice it to userspace via audit.
*/
type_attribute_bounds_av(policydb, scontext, tcontext,
tclass, avd);
}
static int security_validtrans_handle_fail(struct selinux_state *state,
struct selinux_policy *policy,
struct sidtab_entry *oentry,
struct sidtab_entry *nentry,
struct sidtab_entry *tentry,
u16 tclass)
{
struct policydb *p = &policy->policydb;
struct sidtab *sidtab = policy->sidtab;
char *o = NULL, *n = NULL, *t = NULL;
u32 olen, nlen, tlen;
if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
goto out;
if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
goto out;
if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
goto out;
audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
"op=security_validate_transition seresult=denied"
" oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
out:
kfree(o);
kfree(n);
kfree(t);
if (!enforcing_enabled(state))
return 0;
return -EPERM;
}
static int security_compute_validatetrans(struct selinux_state *state,
u32 oldsid, u32 newsid, u32 tasksid,
u16 orig_tclass, bool user)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct sidtab_entry *oentry;
struct sidtab_entry *nentry;
struct sidtab_entry *tentry;
struct class_datum *tclass_datum;
struct constraint_node *constraint;
u16 tclass;
int rc = 0;
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
if (!user)
tclass = unmap_class(&policy->map, orig_tclass);
else
tclass = orig_tclass;
if (!tclass || tclass > policydb->p_classes.nprim) {
rc = -EINVAL;
goto out;
}
tclass_datum = policydb->class_val_to_struct[tclass - 1];
oentry = sidtab_search_entry(sidtab, oldsid);
if (!oentry) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, oldsid);
rc = -EINVAL;
goto out;
}
nentry = sidtab_search_entry(sidtab, newsid);
if (!nentry) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, newsid);
rc = -EINVAL;
goto out;
}
tentry = sidtab_search_entry(sidtab, tasksid);
if (!tentry) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, tasksid);
rc = -EINVAL;
goto out;
}
constraint = tclass_datum->validatetrans;
while (constraint) {
if (!constraint_expr_eval(policydb, &oentry->context,
&nentry->context, &tentry->context,
constraint->expr)) {
if (user)
rc = -EPERM;
else
rc = security_validtrans_handle_fail(state,
policy,
oentry,
nentry,
tentry,
tclass);
goto out;
}
constraint = constraint->next;
}
out:
rcu_read_unlock();
return rc;
}
int security_validate_transition_user(struct selinux_state *state,
u32 oldsid, u32 newsid, u32 tasksid,
u16 tclass)
{
return security_compute_validatetrans(state, oldsid, newsid, tasksid,
tclass, true);
}
int security_validate_transition(struct selinux_state *state,
u32 oldsid, u32 newsid, u32 tasksid,
u16 orig_tclass)
{
return security_compute_validatetrans(state, oldsid, newsid, tasksid,
orig_tclass, false);
}
/*
* security_bounded_transition - check whether the given
* transition is directed to bounded, or not.
* It returns 0, if @newsid is bounded by @oldsid.
* Otherwise, it returns error code.
*
* @state: SELinux state
* @oldsid : current security identifier
* @newsid : destinated security identifier
*/
int security_bounded_transition(struct selinux_state *state,
u32 old_sid, u32 new_sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct sidtab_entry *old_entry, *new_entry;
struct type_datum *type;
int index;
int rc;
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
rc = -EINVAL;
old_entry = sidtab_search_entry(sidtab, old_sid);
if (!old_entry) {
pr_err("SELinux: %s: unrecognized SID %u\n",
__func__, old_sid);
goto out;
}
rc = -EINVAL;
new_entry = sidtab_search_entry(sidtab, new_sid);
if (!new_entry) {
pr_err("SELinux: %s: unrecognized SID %u\n",
__func__, new_sid);
goto out;
}
rc = 0;
/* type/domain unchanged */
if (old_entry->context.type == new_entry->context.type)
goto out;
index = new_entry->context.type;
while (true) {
type = policydb->type_val_to_struct[index - 1];
BUG_ON(!type);
/* not bounded anymore */
rc = -EPERM;
if (!type->bounds)
break;
/* @newsid is bounded by @oldsid */
rc = 0;
if (type->bounds == old_entry->context.type)
break;
index = type->bounds;
}
if (rc) {
char *old_name = NULL;
char *new_name = NULL;
u32 length;
if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
&old_name, &length) &&
!sidtab_entry_to_string(policydb, sidtab, new_entry,
&new_name, &length)) {
audit_log(audit_context(),
GFP_ATOMIC, AUDIT_SELINUX_ERR,
"op=security_bounded_transition "
"seresult=denied "
"oldcontext=%s newcontext=%s",
old_name, new_name);
}
kfree(new_name);
kfree(old_name);
}
out:
rcu_read_unlock();
return rc;
}
static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
{
avd->allowed = 0;
avd->auditallow = 0;
avd->auditdeny = 0xffffffff;
if (policy)
avd->seqno = policy->latest_granting;
else
avd->seqno = 0;
avd->flags = 0;
}
void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
struct avtab_node *node)
{
unsigned int i;
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
if (xpermd->driver != node->datum.u.xperms->driver)
return;
} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
if (!security_xperm_test(node->datum.u.xperms->perms.p,
xpermd->driver))
return;
} else {
BUG();
}
if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
xpermd->used |= XPERMS_ALLOWED;
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
memset(xpermd->allowed->p, 0xff,
sizeof(xpermd->allowed->p));
}
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
xpermd->allowed->p[i] |=
node->datum.u.xperms->perms.p[i];
}
} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
xpermd->used |= XPERMS_AUDITALLOW;
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
memset(xpermd->auditallow->p, 0xff,
sizeof(xpermd->auditallow->p));
}
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
xpermd->auditallow->p[i] |=
node->datum.u.xperms->perms.p[i];
}
} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
xpermd->used |= XPERMS_DONTAUDIT;
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
memset(xpermd->dontaudit->p, 0xff,
sizeof(xpermd->dontaudit->p));
}
if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
xpermd->dontaudit->p[i] |=
node->datum.u.xperms->perms.p[i];
}
} else {
BUG();
}
}
void security_compute_xperms_decision(struct selinux_state *state,
u32 ssid,
u32 tsid,
u16 orig_tclass,
u8 driver,
struct extended_perms_decision *xpermd)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
u16 tclass;
struct context *scontext, *tcontext;
struct avtab_key avkey;
struct avtab_node *node;
struct ebitmap *sattr, *tattr;
struct ebitmap_node *snode, *tnode;
unsigned int i, j;
xpermd->driver = driver;
xpermd->used = 0;
memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
rcu_read_lock();
if (!selinux_initialized(state))
goto allow;
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
scontext = sidtab_search(sidtab, ssid);
if (!scontext) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, ssid);
goto out;
}
tcontext = sidtab_search(sidtab, tsid);
if (!tcontext) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, tsid);
goto out;
}
tclass = unmap_class(&policy->map, orig_tclass);
if (unlikely(orig_tclass && !tclass)) {
if (policydb->allow_unknown)
goto allow;
goto out;
}
if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
goto out;
}
avkey.target_class = tclass;
avkey.specified = AVTAB_XPERMS;
sattr = &policydb->type_attr_map_array[scontext->type - 1];
tattr = &policydb->type_attr_map_array[tcontext->type - 1];
ebitmap_for_each_positive_bit(sattr, snode, i) {
ebitmap_for_each_positive_bit(tattr, tnode, j) {
avkey.source_type = i + 1;
avkey.target_type = j + 1;
for (node = avtab_search_node(&policydb->te_avtab,
&avkey);
node;
node = avtab_search_node_next(node, avkey.specified))
services_compute_xperms_decision(xpermd, node);
cond_compute_xperms(&policydb->te_cond_avtab,
&avkey, xpermd);
}
}
out:
rcu_read_unlock();
return;
allow:
memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
goto out;
}
/**
* security_compute_av - Compute access vector decisions.
* @state: SELinux state
* @ssid: source security identifier
* @tsid: target security identifier
* @orig_tclass: target security class
* @avd: access vector decisions
* @xperms: extended permissions
*
* Compute a set of access vector decisions based on the
* SID pair (@ssid, @tsid) for the permissions in @tclass.
*/
void security_compute_av(struct selinux_state *state,
u32 ssid,
u32 tsid,
u16 orig_tclass,
struct av_decision *avd,
struct extended_perms *xperms)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
u16 tclass;
struct context *scontext = NULL, *tcontext = NULL;
rcu_read_lock();
policy = rcu_dereference(state->policy);
avd_init(policy, avd);
xperms->len = 0;
if (!selinux_initialized(state))
goto allow;
policydb = &policy->policydb;
sidtab = policy->sidtab;
scontext = sidtab_search(sidtab, ssid);
if (!scontext) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, ssid);
goto out;
}
/* permissive domain? */
if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
avd->flags |= AVD_FLAGS_PERMISSIVE;
tcontext = sidtab_search(sidtab, tsid);
if (!tcontext) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, tsid);
goto out;
}
tclass = unmap_class(&policy->map, orig_tclass);
if (unlikely(orig_tclass && !tclass)) {
if (policydb->allow_unknown)
goto allow;
goto out;
}
context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
xperms);
map_decision(&policy->map, orig_tclass, avd,
policydb->allow_unknown);
out:
rcu_read_unlock();
return;
allow:
avd->allowed = 0xffffffff;
goto out;
}
void security_compute_av_user(struct selinux_state *state,
u32 ssid,
u32 tsid,
u16 tclass,
struct av_decision *avd)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct context *scontext = NULL, *tcontext = NULL;
rcu_read_lock();
policy = rcu_dereference(state->policy);
avd_init(policy, avd);
if (!selinux_initialized(state))
goto allow;
policydb = &policy->policydb;
sidtab = policy->sidtab;
scontext = sidtab_search(sidtab, ssid);
if (!scontext) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, ssid);
goto out;
}
/* permissive domain? */
if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
avd->flags |= AVD_FLAGS_PERMISSIVE;
tcontext = sidtab_search(sidtab, tsid);
if (!tcontext) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, tsid);
goto out;
}
if (unlikely(!tclass)) {
if (policydb->allow_unknown)
goto allow;
goto out;
}
context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
NULL);
out:
rcu_read_unlock();
return;
allow:
avd->allowed = 0xffffffff;
goto out;
}
/*
* Write the security context string representation of
* the context structure `context' into a dynamically
* allocated string of the correct size. Set `*scontext'
* to point to this string and set `*scontext_len' to
* the length of the string.
*/
static int context_struct_to_string(struct policydb *p,
struct context *context,
char **scontext, u32 *scontext_len)
{
char *scontextp;
if (scontext)
*scontext = NULL;
*scontext_len = 0;
if (context->len) {
*scontext_len = context->len;
if (scontext) {
*scontext = kstrdup(context->str, GFP_ATOMIC);
if (!(*scontext))
return -ENOMEM;
}
return 0;
}
/* Compute the size of the context. */
*scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
*scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
*scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
*scontext_len += mls_compute_context_len(p, context);
if (!scontext)
return 0;
/* Allocate space for the context; caller must free this space. */
scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
if (!scontextp)
return -ENOMEM;
*scontext = scontextp;
/*
* Copy the user name, role name and type name into the context.
*/
scontextp += sprintf(scontextp, "%s:%s:%s",
sym_name(p, SYM_USERS, context->user - 1),
sym_name(p, SYM_ROLES, context->role - 1),
sym_name(p, SYM_TYPES, context->type - 1));
mls_sid_to_context(p, context, &scontextp);
*scontextp = 0;
return 0;
}
static int sidtab_entry_to_string(struct policydb *p,
struct sidtab *sidtab,
struct sidtab_entry *entry,
char **scontext, u32 *scontext_len)
{
int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
if (rc != -ENOENT)
return rc;
rc = context_struct_to_string(p, &entry->context, scontext,
scontext_len);
if (!rc && scontext)
sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
return rc;
}
#include "initial_sid_to_string.h"
int security_sidtab_hash_stats(struct selinux_state *state, char *page)
{
struct selinux_policy *policy;
int rc;
if (!selinux_initialized(state)) {
pr_err("SELinux: %s: called before initial load_policy\n",
__func__);
return -EINVAL;
}
rcu_read_lock();
policy = rcu_dereference(state->policy);
rc = sidtab_hash_stats(policy->sidtab, page);
rcu_read_unlock();
return rc;
}
const char *security_get_initial_sid_context(u32 sid)
{
if (unlikely(sid > SECINITSID_NUM))
return NULL;
return initial_sid_to_string[sid];
}
static int security_sid_to_context_core(struct selinux_state *state,
u32 sid, char **scontext,
u32 *scontext_len, int force,
int only_invalid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct sidtab_entry *entry;
int rc = 0;
if (scontext)
*scontext = NULL;
*scontext_len = 0;
if (!selinux_initialized(state)) {
if (sid <= SECINITSID_NUM) {
char *scontextp;
const char *s = initial_sid_to_string[sid];
if (!s)
return -EINVAL;
*scontext_len = strlen(s) + 1;
if (!scontext)
return 0;
scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
if (!scontextp)
return -ENOMEM;
*scontext = scontextp;
return 0;
}
pr_err("SELinux: %s: called before initial "
"load_policy on unknown SID %d\n", __func__, sid);
return -EINVAL;
}
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
if (force)
entry = sidtab_search_entry_force(sidtab, sid);
else
entry = sidtab_search_entry(sidtab, sid);
if (!entry) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, sid);
rc = -EINVAL;
goto out_unlock;
}
if (only_invalid && !entry->context.len)
goto out_unlock;
rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
scontext_len);
out_unlock:
rcu_read_unlock();
return rc;
}
/**
* security_sid_to_context - Obtain a context for a given SID.
* @state: SELinux state
* @sid: security identifier, SID
* @scontext: security context
* @scontext_len: length in bytes
*
* Write the string representation of the context associated with @sid
* into a dynamically allocated string of the correct size. Set @scontext
* to point to this string and set @scontext_len to the length of the string.
*/
int security_sid_to_context(struct selinux_state *state,
u32 sid, char **scontext, u32 *scontext_len)
{
return security_sid_to_context_core(state, sid, scontext,
scontext_len, 0, 0);
}
int security_sid_to_context_force(struct selinux_state *state, u32 sid,
char **scontext, u32 *scontext_len)
{
return security_sid_to_context_core(state, sid, scontext,
scontext_len, 1, 0);
}
/**
* security_sid_to_context_inval - Obtain a context for a given SID if it
* is invalid.
* @state: SELinux state
* @sid: security identifier, SID
* @scontext: security context
* @scontext_len: length in bytes
*
* Write the string representation of the context associated with @sid
* into a dynamically allocated string of the correct size, but only if the
* context is invalid in the current policy. Set @scontext to point to
* this string (or NULL if the context is valid) and set @scontext_len to
* the length of the string (or 0 if the context is valid).
*/
int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
char **scontext, u32 *scontext_len)
{
return security_sid_to_context_core(state, sid, scontext,
scontext_len, 1, 1);
}
/*
* Caveat: Mutates scontext.
*/
static int string_to_context_struct(struct policydb *pol,
struct sidtab *sidtabp,
char *scontext,
struct context *ctx,
u32 def_sid)
{
struct role_datum *role;
struct type_datum *typdatum;
struct user_datum *usrdatum;
char *scontextp, *p, oldc;
int rc = 0;
context_init(ctx);
/* Parse the security context. */
rc = -EINVAL;
scontextp = (char *) scontext;
/* Extract the user. */
p = scontextp;
while (*p && *p != ':')
p++;
if (*p == 0)
goto out;
*p++ = 0;
usrdatum = symtab_search(&pol->p_users, scontextp);
if (!usrdatum)
goto out;
ctx->user = usrdatum->value;
/* Extract role. */
scontextp = p;
while (*p && *p != ':')
p++;
if (*p == 0)
goto out;
*p++ = 0;
role = symtab_search(&pol->p_roles, scontextp);
if (!role)
goto out;
ctx->role = role->value;
/* Extract type. */
scontextp = p;
while (*p && *p != ':')
p++;
oldc = *p;
*p++ = 0;
typdatum = symtab_search(&pol->p_types, scontextp);
if (!typdatum || typdatum->attribute)
goto out;
ctx->type = typdatum->value;
rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
if (rc)
goto out;
/* Check the validity of the new context. */
rc = -EINVAL;
if (!policydb_context_isvalid(pol, ctx))
goto out;
rc = 0;
out:
if (rc)
context_destroy(ctx);
return rc;
}
static int security_context_to_sid_core(struct selinux_state *state,
const char *scontext, u32 scontext_len,
u32 *sid, u32 def_sid, gfp_t gfp_flags,
int force)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
char *scontext2, *str = NULL;
struct context context;
int rc = 0;
/* An empty security context is never valid. */
if (!scontext_len)
return -EINVAL;
/* Copy the string to allow changes and ensure a NUL terminator */
scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
if (!scontext2)
return -ENOMEM;
if (!selinux_initialized(state)) {
int i;
for (i = 1; i < SECINITSID_NUM; i++) {
const char *s = initial_sid_to_string[i];
if (s && !strcmp(s, scontext2)) {
*sid = i;
goto out;
}
}
*sid = SECINITSID_KERNEL;
goto out;
}
*sid = SECSID_NULL;
if (force) {
/* Save another copy for storing in uninterpreted form */
rc = -ENOMEM;
str = kstrdup(scontext2, gfp_flags);
if (!str)
goto out;
}
retry:
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
rc = string_to_context_struct(policydb, sidtab, scontext2,
&context, def_sid);
if (rc == -EINVAL && force) {
context.str = str;
context.len = strlen(str) + 1;
str = NULL;
} else if (rc)
goto out_unlock;
rc = sidtab_context_to_sid(sidtab, &context, sid);
if (rc == -ESTALE) {
rcu_read_unlock();
if (context.str) {
str = context.str;
context.str = NULL;
}
context_destroy(&context);
goto retry;
}
context_destroy(&context);
out_unlock:
rcu_read_unlock();
out:
kfree(scontext2);
kfree(str);
return rc;
}
/**
* security_context_to_sid - Obtain a SID for a given security context.
* @state: SELinux state
* @scontext: security context
* @scontext_len: length in bytes
* @sid: security identifier, SID
* @gfp: context for the allocation
*
* Obtains a SID associated with the security context that
* has the string representation specified by @scontext.
* Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
* memory is available, or 0 on success.
*/
int security_context_to_sid(struct selinux_state *state,
const char *scontext, u32 scontext_len, u32 *sid,
gfp_t gfp)
{
return security_context_to_sid_core(state, scontext, scontext_len,
sid, SECSID_NULL, gfp, 0);
}
int security_context_str_to_sid(struct selinux_state *state,
const char *scontext, u32 *sid, gfp_t gfp)
{
return security_context_to_sid(state, scontext, strlen(scontext),
sid, gfp);
}
/**
* security_context_to_sid_default - Obtain a SID for a given security context,
* falling back to specified default if needed.
*
* @state: SELinux state
* @scontext: security context
* @scontext_len: length in bytes
* @sid: security identifier, SID
* @def_sid: default SID to assign on error
* @gfp_flags: the allocator get-free-page (GFP) flags
*
* Obtains a SID associated with the security context that
* has the string representation specified by @scontext.
* The default SID is passed to the MLS layer to be used to allow
* kernel labeling of the MLS field if the MLS field is not present
* (for upgrading to MLS without full relabel).
* Implicitly forces adding of the context even if it cannot be mapped yet.
* Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
* memory is available, or 0 on success.
*/
int security_context_to_sid_default(struct selinux_state *state,
const char *scontext, u32 scontext_len,
u32 *sid, u32 def_sid, gfp_t gfp_flags)
{
return security_context_to_sid_core(state, scontext, scontext_len,
sid, def_sid, gfp_flags, 1);
}
int security_context_to_sid_force(struct selinux_state *state,
const char *scontext, u32 scontext_len,
u32 *sid)
{
return security_context_to_sid_core(state, scontext, scontext_len,
sid, SECSID_NULL, GFP_KERNEL, 1);
}
static int compute_sid_handle_invalid_context(
struct selinux_state *state,
struct selinux_policy *policy,
struct sidtab_entry *sentry,
struct sidtab_entry *tentry,
u16 tclass,
struct context *newcontext)
{
struct policydb *policydb = &policy->policydb;
struct sidtab *sidtab = policy->sidtab;
char *s = NULL, *t = NULL, *n = NULL;
u32 slen, tlen, nlen;
struct audit_buffer *ab;
if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
goto out;
if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
goto out;
if (context_struct_to_string(policydb, newcontext, &n, &nlen))
goto out;
ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
if (!ab)
goto out;
audit_log_format(ab,
"op=security_compute_sid invalid_context=");
/* no need to record the NUL with untrusted strings */
audit_log_n_untrustedstring(ab, n, nlen - 1);
audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
audit_log_end(ab);
out:
kfree(s);
kfree(t);
kfree(n);
if (!enforcing_enabled(state))
return 0;
return -EACCES;
}
static void filename_compute_type(struct policydb *policydb,
struct context *newcontext,
u32 stype, u32 ttype, u16 tclass,
const char *objname)
{
struct filename_trans_key ft;
struct filename_trans_datum *datum;
/*
* Most filename trans rules are going to live in specific directories
* like /dev or /var/run. This bitmap will quickly skip rule searches
* if the ttype does not contain any rules.
*/
if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
return;
ft.ttype = ttype;
ft.tclass = tclass;
ft.name = objname;
datum = policydb_filenametr_search(policydb, &ft);
while (datum) {
if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
newcontext->type = datum->otype;
return;
}
datum = datum->next;
}
}
static int security_compute_sid(struct selinux_state *state,
u32 ssid,
u32 tsid,
u16 orig_tclass,
u32 specified,
const char *objname,
u32 *out_sid,
bool kern)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct class_datum *cladatum;
struct context *scontext, *tcontext, newcontext;
struct sidtab_entry *sentry, *tentry;
struct avtab_key avkey;
struct avtab_datum *avdatum;
struct avtab_node *node;
u16 tclass;
int rc = 0;
bool sock;
if (!selinux_initialized(state)) {
switch (orig_tclass) {
case SECCLASS_PROCESS: /* kernel value */
*out_sid = ssid;
break;
default:
*out_sid = tsid;
break;
}
goto out;
}
retry:
cladatum = NULL;
context_init(&newcontext);
rcu_read_lock();
policy = rcu_dereference(state->policy);
if (kern) {
tclass = unmap_class(&policy->map, orig_tclass);
sock = security_is_socket_class(orig_tclass);
} else {
tclass = orig_tclass;
sock = security_is_socket_class(map_class(&policy->map,
tclass));
}
policydb = &policy->policydb;
sidtab = policy->sidtab;
sentry = sidtab_search_entry(sidtab, ssid);
if (!sentry) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, ssid);
rc = -EINVAL;
goto out_unlock;
}
tentry = sidtab_search_entry(sidtab, tsid);
if (!tentry) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, tsid);
rc = -EINVAL;
goto out_unlock;
}
scontext = &sentry->context;
tcontext = &tentry->context;
if (tclass && tclass <= policydb->p_classes.nprim)
cladatum = policydb->class_val_to_struct[tclass - 1];
/* Set the user identity. */
switch (specified) {
case AVTAB_TRANSITION:
case AVTAB_CHANGE:
if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
newcontext.user = tcontext->user;
} else {
/* notice this gets both DEFAULT_SOURCE and unset */
/* Use the process user identity. */
newcontext.user = scontext->user;
}
break;
case AVTAB_MEMBER:
/* Use the related object owner. */
newcontext.user = tcontext->user;
break;
}
/* Set the role to default values. */
if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
newcontext.role = scontext->role;
} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
newcontext.role = tcontext->role;
} else {
if ((tclass == policydb->process_class) || sock)
newcontext.role = scontext->role;
else
newcontext.role = OBJECT_R_VAL;
}
/* Set the type to default values. */
if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
newcontext.type = scontext->type;
} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
newcontext.type = tcontext->type;
} else {
if ((tclass == policydb->process_class) || sock) {
/* Use the type of process. */
newcontext.type = scontext->type;
} else {
/* Use the type of the related object. */
newcontext.type = tcontext->type;
}
}
/* Look for a type transition/member/change rule. */
avkey.source_type = scontext->type;
avkey.target_type = tcontext->type;
avkey.target_class = tclass;
avkey.specified = specified;
avdatum = avtab_search(&policydb->te_avtab, &avkey);
/* If no permanent rule, also check for enabled conditional rules */
if (!avdatum) {
node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
for (; node; node = avtab_search_node_next(node, specified)) {
if (node->key.specified & AVTAB_ENABLED) {
avdatum = &node->datum;
break;
}
}
}
if (avdatum) {
/* Use the type from the type transition/member/change rule. */
newcontext.type = avdatum->u.data;
}
/* if we have a objname this is a file trans check so check those rules */
if (objname)
filename_compute_type(policydb, &newcontext, scontext->type,
tcontext->type, tclass, objname);
/* Check for class-specific changes. */
if (specified & AVTAB_TRANSITION) {
/* Look for a role transition rule. */
struct role_trans_datum *rtd;
struct role_trans_key rtk = {
.role = scontext->role,
.type = tcontext->type,
.tclass = tclass,
};
rtd = policydb_roletr_search(policydb, &rtk);
if (rtd)
newcontext.role = rtd->new_role;
}
/* Set the MLS attributes.
This is done last because it may allocate memory. */
rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
&newcontext, sock);
if (rc)
goto out_unlock;
/* Check the validity of the context. */
if (!policydb_context_isvalid(policydb, &newcontext)) {
rc = compute_sid_handle_invalid_context(state, policy, sentry,
tentry, tclass,
&newcontext);
if (rc)
goto out_unlock;
}
/* Obtain the sid for the context. */
rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
if (rc == -ESTALE) {
rcu_read_unlock();
context_destroy(&newcontext);
goto retry;
}
out_unlock:
rcu_read_unlock();
context_destroy(&newcontext);
out:
return rc;
}
/**
* security_transition_sid - Compute the SID for a new subject/object.
* @state: SELinux state
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
* @qstr: object name
* @out_sid: security identifier for new subject/object
*
* Compute a SID to use for labeling a new subject or object in the
* class @tclass based on a SID pair (@ssid, @tsid).
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
* if insufficient memory is available, or %0 if the new SID was
* computed successfully.
*/
int security_transition_sid(struct selinux_state *state,
u32 ssid, u32 tsid, u16 tclass,
const struct qstr *qstr, u32 *out_sid)
{
return security_compute_sid(state, ssid, tsid, tclass,
AVTAB_TRANSITION,
qstr ? qstr->name : NULL, out_sid, true);
}
int security_transition_sid_user(struct selinux_state *state,
u32 ssid, u32 tsid, u16 tclass,
const char *objname, u32 *out_sid)
{
return security_compute_sid(state, ssid, tsid, tclass,
AVTAB_TRANSITION,
objname, out_sid, false);
}
/**
* security_member_sid - Compute the SID for member selection.
* @state: SELinux state
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
* @out_sid: security identifier for selected member
*
* Compute a SID to use when selecting a member of a polyinstantiated
* object of class @tclass based on a SID pair (@ssid, @tsid).
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
* if insufficient memory is available, or %0 if the SID was
* computed successfully.
*/
int security_member_sid(struct selinux_state *state,
u32 ssid,
u32 tsid,
u16 tclass,
u32 *out_sid)
{
return security_compute_sid(state, ssid, tsid, tclass,
AVTAB_MEMBER, NULL,
out_sid, false);
}
/**
* security_change_sid - Compute the SID for object relabeling.
* @state: SELinux state
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
* @out_sid: security identifier for selected member
*
* Compute a SID to use for relabeling an object of class @tclass
* based on a SID pair (@ssid, @tsid).
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
* if insufficient memory is available, or %0 if the SID was
* computed successfully.
*/
int security_change_sid(struct selinux_state *state,
u32 ssid,
u32 tsid,
u16 tclass,
u32 *out_sid)
{
return security_compute_sid(state,
ssid, tsid, tclass, AVTAB_CHANGE, NULL,
out_sid, false);
}
static inline int convert_context_handle_invalid_context(
struct selinux_state *state,
struct policydb *policydb,
struct context *context)
{
char *s;
u32 len;
if (enforcing_enabled(state))
return -EINVAL;
if (!context_struct_to_string(policydb, context, &s, &len)) {
pr_warn("SELinux: Context %s would be invalid if enforcing\n",
s);
kfree(s);
}
return 0;
}
/*
* Convert the values in the security context
* structure `oldc' from the values specified
* in the policy `p->oldp' to the values specified
* in the policy `p->newp', storing the new context
* in `newc'. Verify that the context is valid
* under the new policy.
*/
static int convert_context(struct context *oldc, struct context *newc, void *p)
{
struct convert_context_args *args;
struct ocontext *oc;
struct role_datum *role;
struct type_datum *typdatum;
struct user_datum *usrdatum;
char *s;
u32 len;
int rc;
args = p;
if (oldc->str) {
s = kstrdup(oldc->str, GFP_KERNEL);
if (!s)
return -ENOMEM;
rc = string_to_context_struct(args->newp, NULL, s,
newc, SECSID_NULL);
if (rc == -EINVAL) {
/*
* Retain string representation for later mapping.
*
* IMPORTANT: We need to copy the contents of oldc->str
* back into s again because string_to_context_struct()
* may have garbled it.
*/
memcpy(s, oldc->str, oldc->len);
context_init(newc);
newc->str = s;
newc->len = oldc->len;
return 0;
}
kfree(s);
if (rc) {
/* Other error condition, e.g. ENOMEM. */
pr_err("SELinux: Unable to map context %s, rc = %d.\n",
oldc->str, -rc);
return rc;
}
pr_info("SELinux: Context %s became valid (mapped).\n",
oldc->str);
return 0;
}
context_init(newc);
/* Convert the user. */
usrdatum = symtab_search(&args->newp->p_users,
sym_name(args->oldp,
SYM_USERS, oldc->user - 1));
if (!usrdatum)
goto bad;
newc->user = usrdatum->value;
/* Convert the role. */
role = symtab_search(&args->newp->p_roles,
sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
if (!role)
goto bad;
newc->role = role->value;
/* Convert the type. */
typdatum = symtab_search(&args->newp->p_types,
sym_name(args->oldp,
SYM_TYPES, oldc->type - 1));
if (!typdatum)
goto bad;
newc->type = typdatum->value;
/* Convert the MLS fields if dealing with MLS policies */
if (args->oldp->mls_enabled && args->newp->mls_enabled) {
rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
if (rc)
goto bad;
} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
/*
* Switching between non-MLS and MLS policy:
* ensure that the MLS fields of the context for all
* existing entries in the sidtab are filled in with a
* suitable default value, likely taken from one of the
* initial SIDs.
*/
oc = args->newp->ocontexts[OCON_ISID];
while (oc && oc->sid[0] != SECINITSID_UNLABELED)
oc = oc->next;
if (!oc) {
pr_err("SELinux: unable to look up"
" the initial SIDs list\n");
goto bad;
}
rc = mls_range_set(newc, &oc->context[0].range);
if (rc)
goto bad;
}
/* Check the validity of the new context. */
if (!policydb_context_isvalid(args->newp, newc)) {
rc = convert_context_handle_invalid_context(args->state,
args->oldp,
oldc);
if (rc)
goto bad;
}
return 0;
bad:
/* Map old representation to string and save it. */
rc = context_struct_to_string(args->oldp, oldc, &s, &len);
if (rc)
return rc;
context_destroy(newc);
newc->str = s;
newc->len = len;
pr_info("SELinux: Context %s became invalid (unmapped).\n",
newc->str);
return 0;
}
static void security_load_policycaps(struct selinux_state *state,
struct selinux_policy *policy)
{
struct policydb *p;
unsigned int i;
struct ebitmap_node *node;
p = &policy->policydb;
for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
WRITE_ONCE(state->policycap[i],
ebitmap_get_bit(&p->policycaps, i));
for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
pr_info("SELinux: policy capability %s=%d\n",
selinux_policycap_names[i],
ebitmap_get_bit(&p->policycaps, i));
ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
if (i >= ARRAY_SIZE(selinux_policycap_names))
pr_info("SELinux: unknown policy capability %u\n",
i);
}
}
static int security_preserve_bools(struct selinux_policy *oldpolicy,
struct selinux_policy *newpolicy);
static void selinux_policy_free(struct selinux_policy *policy)
{
if (!policy)
return;
sidtab_destroy(policy->sidtab);
kfree(policy->map.mapping);
policydb_destroy(&policy->policydb);
kfree(policy->sidtab);
kfree(policy);
}
static void selinux_policy_cond_free(struct selinux_policy *policy)
{
cond_policydb_destroy_dup(&policy->policydb);
kfree(policy);
}
void selinux_policy_cancel(struct selinux_state *state,
struct selinux_load_state *load_state)
{
struct selinux_policy *oldpolicy;
oldpolicy = rcu_dereference_protected(state->policy,
lockdep_is_held(&state->policy_mutex));
sidtab_cancel_convert(oldpolicy->sidtab);
selinux_policy_free(load_state->policy);
kfree(load_state->convert_data);
}
static void selinux_notify_policy_change(struct selinux_state *state,
u32 seqno)
{
/* Flush external caches and notify userspace of policy load */
avc_ss_reset(state->avc, seqno);
selnl_notify_policyload(seqno);
selinux_status_update_policyload(state, seqno);
selinux_netlbl_cache_invalidate();
selinux_xfrm_notify_policyload();
selinux_ima_measure_state_locked(state);
}
void selinux_policy_commit(struct selinux_state *state,
struct selinux_load_state *load_state)
{
struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
unsigned long flags;
u32 seqno;
oldpolicy = rcu_dereference_protected(state->policy,
lockdep_is_held(&state->policy_mutex));
/* If switching between different policy types, log MLS status */
if (oldpolicy) {
if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
pr_info("SELinux: Disabling MLS support...\n");
else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
pr_info("SELinux: Enabling MLS support...\n");
}
/* Set latest granting seqno for new policy. */
if (oldpolicy)
newpolicy->latest_granting = oldpolicy->latest_granting + 1;
else
newpolicy->latest_granting = 1;
seqno = newpolicy->latest_granting;
/* Install the new policy. */
if (oldpolicy) {
sidtab_freeze_begin(oldpolicy->sidtab, &flags);
rcu_assign_pointer(state->policy, newpolicy);
sidtab_freeze_end(oldpolicy->sidtab, &flags);
} else {
rcu_assign_pointer(state->policy, newpolicy);
}
/* Load the policycaps from the new policy */
security_load_policycaps(state, newpolicy);
if (!selinux_initialized(state)) {
/*
* After first policy load, the security server is
* marked as initialized and ready to handle requests and
* any objects created prior to policy load are then labeled.
*/
selinux_mark_initialized(state);
selinux_complete_init();
}
/* Free the old policy */
synchronize_rcu();
selinux_policy_free(oldpolicy);
kfree(load_state->convert_data);
/* Notify others of the policy change */
selinux_notify_policy_change(state, seqno);
}
/**
* security_load_policy - Load a security policy configuration.
* @state: SELinux state
* @data: binary policy data
* @len: length of data in bytes
* @load_state: policy load state
*
* Load a new set of security policy configuration data,
* validate it and convert the SID table as necessary.
* This function will flush the access vector cache after
* loading the new policy.
*/
int security_load_policy(struct selinux_state *state, void *data, size_t len,
struct selinux_load_state *load_state)
{
struct selinux_policy *newpolicy, *oldpolicy;
struct selinux_policy_convert_data *convert_data;
int rc = 0;
struct policy_file file = { data, len }, *fp = &file;
newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
if (!newpolicy)
return -ENOMEM;
newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
if (!newpolicy->sidtab) {
rc = -ENOMEM;
goto err_policy;
}
rc = policydb_read(&newpolicy->policydb, fp);
if (rc)
goto err_sidtab;
newpolicy->policydb.len = len;
rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
&newpolicy->map);
if (rc)
goto err_policydb;
rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
if (rc) {
pr_err("SELinux: unable to load the initial SIDs\n");
goto err_mapping;
}
if (!selinux_initialized(state)) {
/* First policy load, so no need to preserve state from old policy */
load_state->policy = newpolicy;
load_state->convert_data = NULL;
return 0;
}
oldpolicy = rcu_dereference_protected(state->policy,
lockdep_is_held(&state->policy_mutex));
/* Preserve active boolean values from the old policy */
rc = security_preserve_bools(oldpolicy, newpolicy);
if (rc) {
pr_err("SELinux: unable to preserve booleans\n");
goto err_free_isids;
}
convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
if (!convert_data) {
rc = -ENOMEM;
goto err_free_isids;
}
/*
* Convert the internal representations of contexts
* in the new SID table.
*/
convert_data->args.state = state;
convert_data->args.oldp = &oldpolicy->policydb;
convert_data->args.newp = &newpolicy->policydb;
convert_data->sidtab_params.func = convert_context;
convert_data->sidtab_params.args = &convert_data->args;
convert_data->sidtab_params.target = newpolicy->sidtab;
rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
if (rc) {
pr_err("SELinux: unable to convert the internal"
" representation of contexts in the new SID"
" table\n");
goto err_free_convert_data;
}
load_state->policy = newpolicy;
load_state->convert_data = convert_data;
return 0;
err_free_convert_data:
kfree(convert_data);
err_free_isids:
sidtab_destroy(newpolicy->sidtab);
err_mapping:
kfree(newpolicy->map.mapping);
err_policydb:
policydb_destroy(&newpolicy->policydb);
err_sidtab:
kfree(newpolicy->sidtab);
err_policy:
kfree(newpolicy);
return rc;
}
/**
* ocontext_to_sid - Helper to safely get sid for an ocontext
* @sidtab: SID table
* @c: ocontext structure
* @index: index of the context entry (0 or 1)
* @out_sid: pointer to the resulting SID value
*
* For all ocontexts except OCON_ISID the SID fields are populated
* on-demand when needed. Since updating the SID value is an SMP-sensitive
* operation, this helper must be used to do that safely.
*
* WARNING: This function may return -ESTALE, indicating that the caller
* must retry the operation after re-acquiring the policy pointer!
*/
static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
size_t index, u32 *out_sid)
{
int rc;
u32 sid;
/* Ensure the associated sidtab entry is visible to this thread. */
sid = smp_load_acquire(&c->sid[index]);
if (!sid) {
rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
if (rc)
return rc;
/*
* Ensure the new sidtab entry is visible to other threads
* when they see the SID.
*/
smp_store_release(&c->sid[index], sid);
}
*out_sid = sid;
return 0;
}
/**
* security_port_sid - Obtain the SID for a port.
* @state: SELinux state
* @protocol: protocol number
* @port: port number
* @out_sid: security identifier
*/
int security_port_sid(struct selinux_state *state,
u8 protocol, u16 port, u32 *out_sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct ocontext *c;
int rc;
if (!selinux_initialized(state)) {
*out_sid = SECINITSID_PORT;
return 0;
}
retry:
rc = 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
c = policydb->ocontexts[OCON_PORT];
while (c) {
if (c->u.port.protocol == protocol &&
c->u.port.low_port <= port &&
c->u.port.high_port >= port)
break;
c = c->next;
}
if (c) {
rc = ocontext_to_sid(sidtab, c, 0, out_sid);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc)
goto out;
} else {
*out_sid = SECINITSID_PORT;
}
out:
rcu_read_unlock();
return rc;
}
/**
* security_ib_pkey_sid - Obtain the SID for a pkey.
* @state: SELinux state
* @subnet_prefix: Subnet Prefix
* @pkey_num: pkey number
* @out_sid: security identifier
*/
int security_ib_pkey_sid(struct selinux_state *state,
u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct ocontext *c;
int rc;
if (!selinux_initialized(state)) {
*out_sid = SECINITSID_UNLABELED;
return 0;
}
retry:
rc = 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
c = policydb->ocontexts[OCON_IBPKEY];
while (c) {
if (c->u.ibpkey.low_pkey <= pkey_num &&
c->u.ibpkey.high_pkey >= pkey_num &&
c->u.ibpkey.subnet_prefix == subnet_prefix)
break;
c = c->next;
}
if (c) {
rc = ocontext_to_sid(sidtab, c, 0, out_sid);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc)
goto out;
} else
*out_sid = SECINITSID_UNLABELED;
out:
rcu_read_unlock();
return rc;
}
/**
* security_ib_endport_sid - Obtain the SID for a subnet management interface.
* @state: SELinux state
* @dev_name: device name
* @port_num: port number
* @out_sid: security identifier
*/
int security_ib_endport_sid(struct selinux_state *state,
const char *dev_name, u8 port_num, u32 *out_sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct ocontext *c;
int rc;
if (!selinux_initialized(state)) {
*out_sid = SECINITSID_UNLABELED;
return 0;
}
retry:
rc = 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
c = policydb->ocontexts[OCON_IBENDPORT];
while (c) {
if (c->u.ibendport.port == port_num &&
!strncmp(c->u.ibendport.dev_name,
dev_name,
IB_DEVICE_NAME_MAX))
break;
c = c->next;
}
if (c) {
rc = ocontext_to_sid(sidtab, c, 0, out_sid);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc)
goto out;
} else
*out_sid = SECINITSID_UNLABELED;
out:
rcu_read_unlock();
return rc;
}
/**
* security_netif_sid - Obtain the SID for a network interface.
* @state: SELinux state
* @name: interface name
* @if_sid: interface SID
*/
int security_netif_sid(struct selinux_state *state,
char *name, u32 *if_sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
int rc;
struct ocontext *c;
if (!selinux_initialized(state)) {
*if_sid = SECINITSID_NETIF;
return 0;
}
retry:
rc = 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
c = policydb->ocontexts[OCON_NETIF];
while (c) {
if (strcmp(name, c->u.name) == 0)
break;
c = c->next;
}
if (c) {
rc = ocontext_to_sid(sidtab, c, 0, if_sid);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc)
goto out;
} else
*if_sid = SECINITSID_NETIF;
out:
rcu_read_unlock();
return rc;
}
static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
{
int i, fail = 0;
for (i = 0; i < 4; i++)
if (addr[i] != (input[i] & mask[i])) {
fail = 1;
break;
}
return !fail;
}
/**
* security_node_sid - Obtain the SID for a node (host).
* @state: SELinux state
* @domain: communication domain aka address family
* @addrp: address
* @addrlen: address length in bytes
* @out_sid: security identifier
*/
int security_node_sid(struct selinux_state *state,
u16 domain,
void *addrp,
u32 addrlen,
u32 *out_sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
int rc;
struct ocontext *c;
if (!selinux_initialized(state)) {
*out_sid = SECINITSID_NODE;
return 0;
}
retry:
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
switch (domain) {
case AF_INET: {
u32 addr;
rc = -EINVAL;
if (addrlen != sizeof(u32))
goto out;
addr = *((u32 *)addrp);
c = policydb->ocontexts[OCON_NODE];
while (c) {
if (c->u.node.addr == (addr & c->u.node.mask))
break;
c = c->next;
}
break;
}
case AF_INET6:
rc = -EINVAL;
if (addrlen != sizeof(u64) * 2)
goto out;
c = policydb->ocontexts[OCON_NODE6];
while (c) {
if (match_ipv6_addrmask(addrp, c->u.node6.addr,
c->u.node6.mask))
break;
c = c->next;
}
break;
default:
rc = 0;
*out_sid = SECINITSID_NODE;
goto out;
}
if (c) {
rc = ocontext_to_sid(sidtab, c, 0, out_sid);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc)
goto out;
} else {
*out_sid = SECINITSID_NODE;
}
rc = 0;
out:
rcu_read_unlock();
return rc;
}
#define SIDS_NEL 25
/**
* security_get_user_sids - Obtain reachable SIDs for a user.
* @state: SELinux state
* @fromsid: starting SID
* @username: username
* @sids: array of reachable SIDs for user
* @nel: number of elements in @sids
*
* Generate the set of SIDs for legal security contexts
* for a given user that can be reached by @fromsid.
* Set *@sids to point to a dynamically allocated
* array containing the set of SIDs. Set *@nel to the
* number of elements in the array.
*/
int security_get_user_sids(struct selinux_state *state,
u32 fromsid,
char *username,
u32 **sids,
u32 *nel)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct context *fromcon, usercon;
u32 *mysids = NULL, *mysids2, sid;
u32 i, j, mynel, maxnel = SIDS_NEL;
struct user_datum *user;
struct role_datum *role;
struct ebitmap_node *rnode, *tnode;
int rc;
*sids = NULL;
*nel = 0;
if (!selinux_initialized(state))
return 0;
mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
if (!mysids)
return -ENOMEM;
retry:
mynel = 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
context_init(&usercon);
rc = -EINVAL;
fromcon = sidtab_search(sidtab, fromsid);
if (!fromcon)
goto out_unlock;
rc = -EINVAL;
user = symtab_search(&policydb->p_users, username);
if (!user)
goto out_unlock;
usercon.user = user->value;
ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
role = policydb->role_val_to_struct[i];
usercon.role = i + 1;
ebitmap_for_each_positive_bit(&role->types, tnode, j) {
usercon.type = j + 1;
if (mls_setup_user_range(policydb, fromcon, user,
&usercon))
continue;
rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc)
goto out_unlock;
if (mynel < maxnel) {
mysids[mynel++] = sid;
} else {
rc = -ENOMEM;
maxnel += SIDS_NEL;
mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
if (!mysids2)
goto out_unlock;
memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
kfree(mysids);
mysids = mysids2;
mysids[mynel++] = sid;
}
}
}
rc = 0;
out_unlock:
rcu_read_unlock();
if (rc || !mynel) {
kfree(mysids);
return rc;
}
rc = -ENOMEM;
mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
if (!mysids2) {
kfree(mysids);
return rc;
}
for (i = 0, j = 0; i < mynel; i++) {
struct av_decision dummy_avd;
rc = avc_has_perm_noaudit(state,
fromsid, mysids[i],
SECCLASS_PROCESS, /* kernel value */
PROCESS__TRANSITION, AVC_STRICT,
&dummy_avd);
if (!rc)
mysids2[j++] = mysids[i];
cond_resched();
}
kfree(mysids);
*sids = mysids2;
*nel = j;
return 0;
}
/**
* __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
* @policy: policy
* @fstype: filesystem type
* @path: path from root of mount
* @orig_sclass: file security class
* @sid: SID for path
*
* Obtain a SID to use for a file in a filesystem that
* cannot support xattr or use a fixed labeling behavior like
* transition SIDs or task SIDs.
*
* WARNING: This function may return -ESTALE, indicating that the caller
* must retry the operation after re-acquiring the policy pointer!
*/
static inline int __security_genfs_sid(struct selinux_policy *policy,
const char *fstype,
char *path,
u16 orig_sclass,
u32 *sid)
{
struct policydb *policydb = &policy->policydb;
struct sidtab *sidtab = policy->sidtab;
int len;
u16 sclass;
struct genfs *genfs;
struct ocontext *c;
int cmp = 0;
while (path[0] == '/' && path[1] == '/')
path++;
sclass = unmap_class(&policy->map, orig_sclass);
*sid = SECINITSID_UNLABELED;
for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
cmp = strcmp(fstype, genfs->fstype);
if (cmp <= 0)
break;
}
if (!genfs || cmp)
return -ENOENT;
for (c = genfs->head; c; c = c->next) {
len = strlen(c->u.name);
if ((!c->v.sclass || sclass == c->v.sclass) &&
(strncmp(c->u.name, path, len) == 0))
break;
}
if (!c)
return -ENOENT;
return ocontext_to_sid(sidtab, c, 0, sid);
}
/**
* security_genfs_sid - Obtain a SID for a file in a filesystem
* @state: SELinux state
* @fstype: filesystem type
* @path: path from root of mount
* @orig_sclass: file security class
* @sid: SID for path
*
* Acquire policy_rwlock before calling __security_genfs_sid() and release
* it afterward.
*/
int security_genfs_sid(struct selinux_state *state,
const char *fstype,
char *path,
u16 orig_sclass,
u32 *sid)
{
struct selinux_policy *policy;
int retval;
if (!selinux_initialized(state)) {
*sid = SECINITSID_UNLABELED;
return 0;
}
do {
rcu_read_lock();
policy = rcu_dereference(state->policy);
retval = __security_genfs_sid(policy, fstype, path,
orig_sclass, sid);
rcu_read_unlock();
} while (retval == -ESTALE);
return retval;
}
int selinux_policy_genfs_sid(struct selinux_policy *policy,
const char *fstype,
char *path,
u16 orig_sclass,
u32 *sid)
{
/* no lock required, policy is not yet accessible by other threads */
return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
}
/**
* security_fs_use - Determine how to handle labeling for a filesystem.
* @state: SELinux state
* @sb: superblock in question
*/
int security_fs_use(struct selinux_state *state, struct super_block *sb)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
int rc;
struct ocontext *c;
struct superblock_security_struct *sbsec = selinux_superblock(sb);
const char *fstype = sb->s_type->name;
if (!selinux_initialized(state)) {
sbsec->behavior = SECURITY_FS_USE_NONE;
sbsec->sid = SECINITSID_UNLABELED;
return 0;
}
retry:
rc = 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
c = policydb->ocontexts[OCON_FSUSE];
while (c) {
if (strcmp(fstype, c->u.name) == 0)
break;
c = c->next;
}
if (c) {
sbsec->behavior = c->v.behavior;
rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc)
goto out;
} else {
rc = __security_genfs_sid(policy, fstype, "/",
SECCLASS_DIR, &sbsec->sid);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc) {
sbsec->behavior = SECURITY_FS_USE_NONE;
rc = 0;
} else {
sbsec->behavior = SECURITY_FS_USE_GENFS;
}
}
out:
rcu_read_unlock();
return rc;
}
int security_get_bools(struct selinux_policy *policy,
u32 *len, char ***names, int **values)
{
struct policydb *policydb;
u32 i;
int rc;
policydb = &policy->policydb;
*names = NULL;
*values = NULL;
rc = 0;
*len = policydb->p_bools.nprim;
if (!*len)
goto out;
rc = -ENOMEM;
*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
if (!*names)
goto err;
rc = -ENOMEM;
*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
if (!*values)
goto err;
for (i = 0; i < *len; i++) {
(*values)[i] = policydb->bool_val_to_struct[i]->state;
rc = -ENOMEM;
(*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
GFP_ATOMIC);
if (!(*names)[i])
goto err;
}
rc = 0;
out:
return rc;
err:
if (*names) {
for (i = 0; i < *len; i++)
kfree((*names)[i]);
kfree(*names);
}
kfree(*values);
*len = 0;
*names = NULL;
*values = NULL;
goto out;
}
int security_set_bools(struct selinux_state *state, u32 len, int *values)
{
struct selinux_policy *newpolicy, *oldpolicy;
int rc;
u32 i, seqno = 0;
if (!selinux_initialized(state))
return -EINVAL;
oldpolicy = rcu_dereference_protected(state->policy,
lockdep_is_held(&state->policy_mutex));
/* Consistency check on number of booleans, should never fail */
if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
return -EINVAL;
newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
if (!newpolicy)
return -ENOMEM;
/*
* Deep copy only the parts of the policydb that might be
* modified as a result of changing booleans.
*/
rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
if (rc) {
kfree(newpolicy);
return -ENOMEM;
}
/* Update the boolean states in the copy */
for (i = 0; i < len; i++) {
int new_state = !!values[i];
int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
if (new_state != old_state) {
audit_log(audit_context(), GFP_ATOMIC,
AUDIT_MAC_CONFIG_CHANGE,
"bool=%s val=%d old_val=%d auid=%u ses=%u",
sym_name(&newpolicy->policydb, SYM_BOOLS, i),
new_state,
old_state,
from_kuid(&init_user_ns, audit_get_loginuid(current)),
audit_get_sessionid(current));
newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
}
}
/* Re-evaluate the conditional rules in the copy */
evaluate_cond_nodes(&newpolicy->policydb);
/* Set latest granting seqno for new policy */
newpolicy->latest_granting = oldpolicy->latest_granting + 1;
seqno = newpolicy->latest_granting;
/* Install the new policy */
rcu_assign_pointer(state->policy, newpolicy);
/*
* Free the conditional portions of the old policydb
* that were copied for the new policy, and the oldpolicy
* structure itself but not what it references.
*/
synchronize_rcu();
selinux_policy_cond_free(oldpolicy);
/* Notify others of the policy change */
selinux_notify_policy_change(state, seqno);
return 0;
}
int security_get_bool_value(struct selinux_state *state,
u32 index)
{
struct selinux_policy *policy;
struct policydb *policydb;
int rc;
u32 len;
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
rc = -EFAULT;
len = policydb->p_bools.nprim;
if (index >= len)
goto out;
rc = policydb->bool_val_to_struct[index]->state;
out:
rcu_read_unlock();
return rc;
}
static int security_preserve_bools(struct selinux_policy *oldpolicy,
struct selinux_policy *newpolicy)
{
int rc, *bvalues = NULL;
char **bnames = NULL;
struct cond_bool_datum *booldatum;
u32 i, nbools = 0;
rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
if (rc)
goto out;
for (i = 0; i < nbools; i++) {
booldatum = symtab_search(&newpolicy->policydb.p_bools,
bnames[i]);
if (booldatum)
booldatum->state = bvalues[i];
}
evaluate_cond_nodes(&newpolicy->policydb);
out:
if (bnames) {
for (i = 0; i < nbools; i++)
kfree(bnames[i]);
}
kfree(bnames);
kfree(bvalues);
return rc;
}
/*
* security_sid_mls_copy() - computes a new sid based on the given
* sid and the mls portion of mls_sid.
*/
int security_sid_mls_copy(struct selinux_state *state,
u32 sid, u32 mls_sid, u32 *new_sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
struct context *context1;
struct context *context2;
struct context newcon;
char *s;
u32 len;
int rc;
if (!selinux_initialized(state)) {
*new_sid = sid;
return 0;
}
retry:
rc = 0;
context_init(&newcon);
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
if (!policydb->mls_enabled) {
*new_sid = sid;
goto out_unlock;
}
rc = -EINVAL;
context1 = sidtab_search(sidtab, sid);
if (!context1) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, sid);
goto out_unlock;
}
rc = -EINVAL;
context2 = sidtab_search(sidtab, mls_sid);
if (!context2) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, mls_sid);
goto out_unlock;
}
newcon.user = context1->user;
newcon.role = context1->role;
newcon.type = context1->type;
rc = mls_context_cpy(&newcon, context2);
if (rc)
goto out_unlock;
/* Check the validity of the new context. */
if (!policydb_context_isvalid(policydb, &newcon)) {
rc = convert_context_handle_invalid_context(state, policydb,
&newcon);
if (rc) {
if (!context_struct_to_string(policydb, &newcon, &s,
&len)) {
struct audit_buffer *ab;
ab = audit_log_start(audit_context(),
GFP_ATOMIC,
AUDIT_SELINUX_ERR);
audit_log_format(ab,
"op=security_sid_mls_copy invalid_context=");
/* don't record NUL with untrusted strings */
audit_log_n_untrustedstring(ab, s, len - 1);
audit_log_end(ab);
kfree(s);
}
goto out_unlock;
}
}
rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
if (rc == -ESTALE) {
rcu_read_unlock();
context_destroy(&newcon);
goto retry;
}
out_unlock:
rcu_read_unlock();
context_destroy(&newcon);
return rc;
}
/**
* security_net_peersid_resolve - Compare and resolve two network peer SIDs
* @state: SELinux state
* @nlbl_sid: NetLabel SID
* @nlbl_type: NetLabel labeling protocol type
* @xfrm_sid: XFRM SID
* @peer_sid: network peer sid
*
* Description:
* Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
* resolved into a single SID it is returned via @peer_sid and the function
* returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
* returns a negative value. A table summarizing the behavior is below:
*
* | function return | @sid
* ------------------------------+-----------------+-----------------
* no peer labels | 0 | SECSID_NULL
* single peer label | 0 | <peer_label>
* multiple, consistent labels | 0 | <peer_label>
* multiple, inconsistent labels | -<errno> | SECSID_NULL
*
*/
int security_net_peersid_resolve(struct selinux_state *state,
u32 nlbl_sid, u32 nlbl_type,
u32 xfrm_sid,
u32 *peer_sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
int rc;
struct context *nlbl_ctx;
struct context *xfrm_ctx;
*peer_sid = SECSID_NULL;
/* handle the common (which also happens to be the set of easy) cases
* right away, these two if statements catch everything involving a
* single or absent peer SID/label */
if (xfrm_sid == SECSID_NULL) {
*peer_sid = nlbl_sid;
return 0;
}
/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
* and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
* is present */
if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
*peer_sid = xfrm_sid;
return 0;
}
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
/*
* We don't need to check initialized here since the only way both
* nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
* security server was initialized and state->initialized was true.
*/
if (!policydb->mls_enabled) {
rc = 0;
goto out;
}
rc = -EINVAL;
nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
if (!nlbl_ctx) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, nlbl_sid);
goto out;
}
rc = -EINVAL;
xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
if (!xfrm_ctx) {
pr_err("SELinux: %s: unrecognized SID %d\n",
__func__, xfrm_sid);
goto out;
}
rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
if (rc)
goto out;
/* at present NetLabel SIDs/labels really only carry MLS
* information so if the MLS portion of the NetLabel SID
* matches the MLS portion of the labeled XFRM SID/label
* then pass along the XFRM SID as it is the most
* expressive */
*peer_sid = xfrm_sid;
out:
rcu_read_unlock();
return rc;
}
static int get_classes_callback(void *k, void *d, void *args)
{
struct class_datum *datum = d;
char *name = k, **classes = args;
int value = datum->value - 1;
classes[value] = kstrdup(name, GFP_ATOMIC);
if (!classes[value])
return -ENOMEM;
return 0;
}
int security_get_classes(struct selinux_policy *policy,
char ***classes, int *nclasses)
{
struct policydb *policydb;
int rc;
policydb = &policy->policydb;
rc = -ENOMEM;
*nclasses = policydb->p_classes.nprim;
*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
if (!*classes)
goto out;
rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
*classes);
if (rc) {
int i;
for (i = 0; i < *nclasses; i++)
kfree((*classes)[i]);
kfree(*classes);
}
out:
return rc;
}
static int get_permissions_callback(void *k, void *d, void *args)
{
struct perm_datum *datum = d;
char *name = k, **perms = args;
int value = datum->value - 1;
perms[value] = kstrdup(name, GFP_ATOMIC);
if (!perms[value])
return -ENOMEM;
return 0;
}
int security_get_permissions(struct selinux_policy *policy,
char *class, char ***perms, int *nperms)
{
struct policydb *policydb;
int rc, i;
struct class_datum *match;
policydb = &policy->policydb;
rc = -EINVAL;
match = symtab_search(&policydb->p_classes, class);
if (!match) {
pr_err("SELinux: %s: unrecognized class %s\n",
__func__, class);
goto out;
}
rc = -ENOMEM;
*nperms = match->permissions.nprim;
*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
if (!*perms)
goto out;
if (match->comdatum) {
rc = hashtab_map(&match->comdatum->permissions.table,
get_permissions_callback, *perms);
if (rc)
goto err;
}
rc = hashtab_map(&match->permissions.table, get_permissions_callback,
*perms);
if (rc)
goto err;
out:
return rc;
err:
for (i = 0; i < *nperms; i++)
kfree((*perms)[i]);
kfree(*perms);
return rc;
}
int security_get_reject_unknown(struct selinux_state *state)
{
struct selinux_policy *policy;
int value;
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
value = policy->policydb.reject_unknown;
rcu_read_unlock();
return value;
}
int security_get_allow_unknown(struct selinux_state *state)
{
struct selinux_policy *policy;
int value;
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
value = policy->policydb.allow_unknown;
rcu_read_unlock();
return value;
}
/**
* security_policycap_supported - Check for a specific policy capability
* @state: SELinux state
* @req_cap: capability
*
* Description:
* This function queries the currently loaded policy to see if it supports the
* capability specified by @req_cap. Returns true (1) if the capability is
* supported, false (0) if it isn't supported.
*
*/
int security_policycap_supported(struct selinux_state *state,
unsigned int req_cap)
{
struct selinux_policy *policy;
int rc;
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
rcu_read_unlock();
return rc;
}
struct selinux_audit_rule {
u32 au_seqno;
struct context au_ctxt;
};
void selinux_audit_rule_free(void *vrule)
{
struct selinux_audit_rule *rule = vrule;
if (rule) {
context_destroy(&rule->au_ctxt);
kfree(rule);
}
}
int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
{
struct selinux_state *state = &selinux_state;
struct selinux_policy *policy;
struct policydb *policydb;
struct selinux_audit_rule *tmprule;
struct role_datum *roledatum;
struct type_datum *typedatum;
struct user_datum *userdatum;
struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
int rc = 0;
*rule = NULL;
if (!selinux_initialized(state))
return -EOPNOTSUPP;
switch (field) {
case AUDIT_SUBJ_USER:
case AUDIT_SUBJ_ROLE:
case AUDIT_SUBJ_TYPE:
case AUDIT_OBJ_USER:
case AUDIT_OBJ_ROLE:
case AUDIT_OBJ_TYPE:
/* only 'equals' and 'not equals' fit user, role, and type */
if (op != Audit_equal && op != Audit_not_equal)
return -EINVAL;
break;
case AUDIT_SUBJ_SEN:
case AUDIT_SUBJ_CLR:
case AUDIT_OBJ_LEV_LOW:
case AUDIT_OBJ_LEV_HIGH:
/* we do not allow a range, indicated by the presence of '-' */
if (strchr(rulestr, '-'))
return -EINVAL;
break;
default:
/* only the above fields are valid */
return -EINVAL;
}
tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
if (!tmprule)
return -ENOMEM;
context_init(&tmprule->au_ctxt);
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
tmprule->au_seqno = policy->latest_granting;
switch (field) {
case AUDIT_SUBJ_USER:
case AUDIT_OBJ_USER:
rc = -EINVAL;
userdatum = symtab_search(&policydb->p_users, rulestr);
if (!userdatum)
goto out;
tmprule->au_ctxt.user = userdatum->value;
break;
case AUDIT_SUBJ_ROLE:
case AUDIT_OBJ_ROLE:
rc = -EINVAL;
roledatum = symtab_search(&policydb->p_roles, rulestr);
if (!roledatum)
goto out;
tmprule->au_ctxt.role = roledatum->value;
break;
case AUDIT_SUBJ_TYPE:
case AUDIT_OBJ_TYPE:
rc = -EINVAL;
typedatum = symtab_search(&policydb->p_types, rulestr);
if (!typedatum)
goto out;
tmprule->au_ctxt.type = typedatum->value;
break;
case AUDIT_SUBJ_SEN:
case AUDIT_SUBJ_CLR:
case AUDIT_OBJ_LEV_LOW:
case AUDIT_OBJ_LEV_HIGH:
rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
GFP_ATOMIC);
if (rc)
goto out;
break;
}
rc = 0;
out:
rcu_read_unlock();
if (rc) {
selinux_audit_rule_free(tmprule);
tmprule = NULL;
}
*rule = tmprule;
return rc;
}
/* Check to see if the rule contains any selinux fields */
int selinux_audit_rule_known(struct audit_krule *rule)
{
int i;
for (i = 0; i < rule->field_count; i++) {
struct audit_field *f = &rule->fields[i];
switch (f->type) {
case AUDIT_SUBJ_USER:
case AUDIT_SUBJ_ROLE:
case AUDIT_SUBJ_TYPE:
case AUDIT_SUBJ_SEN:
case AUDIT_SUBJ_CLR:
case AUDIT_OBJ_USER:
case AUDIT_OBJ_ROLE:
case AUDIT_OBJ_TYPE:
case AUDIT_OBJ_LEV_LOW:
case AUDIT_OBJ_LEV_HIGH:
return 1;
}
}
return 0;
}
int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
{
struct selinux_state *state = &selinux_state;
struct selinux_policy *policy;
struct context *ctxt;
struct mls_level *level;
struct selinux_audit_rule *rule = vrule;
int match = 0;
if (unlikely(!rule)) {
WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
return -ENOENT;
}
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
if (rule->au_seqno < policy->latest_granting) {
match = -ESTALE;
goto out;
}
ctxt = sidtab_search(policy->sidtab, sid);
if (unlikely(!ctxt)) {
WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
sid);
match = -ENOENT;
goto out;
}
/* a field/op pair that is not caught here will simply fall through
without a match */
switch (field) {
case AUDIT_SUBJ_USER:
case AUDIT_OBJ_USER:
switch (op) {
case Audit_equal:
match = (ctxt->user == rule->au_ctxt.user);
break;
case Audit_not_equal:
match = (ctxt->user != rule->au_ctxt.user);
break;
}
break;
case AUDIT_SUBJ_ROLE:
case AUDIT_OBJ_ROLE:
switch (op) {
case Audit_equal:
match = (ctxt->role == rule->au_ctxt.role);
break;
case Audit_not_equal:
match = (ctxt->role != rule->au_ctxt.role);
break;
}
break;
case AUDIT_SUBJ_TYPE:
case AUDIT_OBJ_TYPE:
switch (op) {
case Audit_equal:
match = (ctxt->type == rule->au_ctxt.type);
break;
case Audit_not_equal:
match = (ctxt->type != rule->au_ctxt.type);
break;
}
break;
case AUDIT_SUBJ_SEN:
case AUDIT_SUBJ_CLR:
case AUDIT_OBJ_LEV_LOW:
case AUDIT_OBJ_LEV_HIGH:
level = ((field == AUDIT_SUBJ_SEN ||
field == AUDIT_OBJ_LEV_LOW) ?
&ctxt->range.level[0] : &ctxt->range.level[1]);
switch (op) {
case Audit_equal:
match = mls_level_eq(&rule->au_ctxt.range.level[0],
level);
break;
case Audit_not_equal:
match = !mls_level_eq(&rule->au_ctxt.range.level[0],
level);
break;
case Audit_lt:
match = (mls_level_dom(&rule->au_ctxt.range.level[0],
level) &&
!mls_level_eq(&rule->au_ctxt.range.level[0],
level));
break;
case Audit_le:
match = mls_level_dom(&rule->au_ctxt.range.level[0],
level);
break;
case Audit_gt:
match = (mls_level_dom(level,
&rule->au_ctxt.range.level[0]) &&
!mls_level_eq(level,
&rule->au_ctxt.range.level[0]));
break;
case Audit_ge:
match = mls_level_dom(level,
&rule->au_ctxt.range.level[0]);
break;
}
}
out:
rcu_read_unlock();
return match;
}
static int aurule_avc_callback(u32 event)
{
if (event == AVC_CALLBACK_RESET)
return audit_update_lsm_rules();
return 0;
}
static int __init aurule_init(void)
{
int err;
err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
if (err)
panic("avc_add_callback() failed, error %d\n", err);
return err;
}
__initcall(aurule_init);
#ifdef CONFIG_NETLABEL
/**
* security_netlbl_cache_add - Add an entry to the NetLabel cache
* @secattr: the NetLabel packet security attributes
* @sid: the SELinux SID
*
* Description:
* Attempt to cache the context in @ctx, which was derived from the packet in
* @skb, in the NetLabel subsystem cache. This function assumes @secattr has
* already been initialized.
*
*/
static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
u32 sid)
{
u32 *sid_cache;
sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
if (sid_cache == NULL)
return;
secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
if (secattr->cache == NULL) {
kfree(sid_cache);
return;
}
*sid_cache = sid;
secattr->cache->free = kfree;
secattr->cache->data = sid_cache;
secattr->flags |= NETLBL_SECATTR_CACHE;
}
/**
* security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
* @state: SELinux state
* @secattr: the NetLabel packet security attributes
* @sid: the SELinux SID
*
* Description:
* Convert the given NetLabel security attributes in @secattr into a
* SELinux SID. If the @secattr field does not contain a full SELinux
* SID/context then use SECINITSID_NETMSG as the foundation. If possible the
* 'cache' field of @secattr is set and the CACHE flag is set; this is to
* allow the @secattr to be used by NetLabel to cache the secattr to SID
* conversion for future lookups. Returns zero on success, negative values on
* failure.
*
*/
int security_netlbl_secattr_to_sid(struct selinux_state *state,
struct netlbl_lsm_secattr *secattr,
u32 *sid)
{
struct selinux_policy *policy;
struct policydb *policydb;
struct sidtab *sidtab;
int rc;
struct context *ctx;
struct context ctx_new;
if (!selinux_initialized(state)) {
*sid = SECSID_NULL;
return 0;
}
retry:
rc = 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
sidtab = policy->sidtab;
if (secattr->flags & NETLBL_SECATTR_CACHE)
*sid = *(u32 *)secattr->cache->data;
else if (secattr->flags & NETLBL_SECATTR_SECID)
*sid = secattr->attr.secid;
else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
rc = -EIDRM;
ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
if (ctx == NULL)
goto out;
context_init(&ctx_new);
ctx_new.user = ctx->user;
ctx_new.role = ctx->role;
ctx_new.type = ctx->type;
mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
if (rc)
goto out;
}
rc = -EIDRM;
if (!mls_context_isvalid(policydb, &ctx_new)) {
ebitmap_destroy(&ctx_new.range.level[0].cat);
goto out;
}
rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
ebitmap_destroy(&ctx_new.range.level[0].cat);
if (rc == -ESTALE) {
rcu_read_unlock();
goto retry;
}
if (rc)
goto out;
security_netlbl_cache_add(secattr, *sid);
} else
*sid = SECSID_NULL;
out:
rcu_read_unlock();
return rc;
}
/**
* security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
* @state: SELinux state
* @sid: the SELinux SID
* @secattr: the NetLabel packet security attributes
*
* Description:
* Convert the given SELinux SID in @sid into a NetLabel security attribute.
* Returns zero on success, negative values on failure.
*
*/
int security_netlbl_sid_to_secattr(struct selinux_state *state,
u32 sid, struct netlbl_lsm_secattr *secattr)
{
struct selinux_policy *policy;
struct policydb *policydb;
int rc;
struct context *ctx;
if (!selinux_initialized(state))
return 0;
rcu_read_lock();
policy = rcu_dereference(state->policy);
policydb = &policy->policydb;
rc = -ENOENT;
ctx = sidtab_search(policy->sidtab, sid);
if (ctx == NULL)
goto out;
rc = -ENOMEM;
secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
GFP_ATOMIC);
if (secattr->domain == NULL)
goto out;
secattr->attr.secid = sid;
secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
mls_export_netlbl_lvl(policydb, ctx, secattr);
rc = mls_export_netlbl_cat(policydb, ctx, secattr);
out:
rcu_read_unlock();
return rc;
}
#endif /* CONFIG_NETLABEL */
/**
* __security_read_policy - read the policy.
* @policy: SELinux policy
* @data: binary policy data
* @len: length of data in bytes
*
*/
static int __security_read_policy(struct selinux_policy *policy,
void *data, size_t *len)
{
int rc;
struct policy_file fp;
fp.data = data;
fp.len = *len;
rc = policydb_write(&policy->policydb, &fp);
if (rc)
return rc;
*len = (unsigned long)fp.data - (unsigned long)data;
return 0;
}
/**
* security_read_policy - read the policy.
* @state: selinux_state
* @data: binary policy data
* @len: length of data in bytes
*
*/
int security_read_policy(struct selinux_state *state,
void **data, size_t *len)
{
struct selinux_policy *policy;
policy = rcu_dereference_protected(
state->policy, lockdep_is_held(&state->policy_mutex));
if (!policy)
return -EINVAL;
*len = policy->policydb.len;
*data = vmalloc_user(*len);
if (!*data)
return -ENOMEM;
return __security_read_policy(policy, *data, len);
}
/**
* security_read_state_kernel - read the policy.
* @state: selinux_state
* @data: binary policy data
* @len: length of data in bytes
*
* Allocates kernel memory for reading SELinux policy.
* This function is for internal use only and should not
* be used for returning data to user space.
*
* This function must be called with policy_mutex held.
*/
int security_read_state_kernel(struct selinux_state *state,
void **data, size_t *len)
{
struct selinux_policy *policy;
policy = rcu_dereference_protected(
state->policy, lockdep_is_held(&state->policy_mutex));
if (!policy)
return -EINVAL;
*len = policy->policydb.len;
*data = vmalloc(*len);
if (!*data)
return -ENOMEM;
return __security_read_policy(policy, *data, len);
}
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