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-rw-r--r--security/selinux/ss/services.c273
1 files changed, 154 insertions, 119 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index b3efae2..cf27b3e 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -26,6 +26,10 @@
*
* 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.
@@ -87,11 +91,10 @@ static u32 latest_granting;
static int context_struct_to_string(struct context *context, char **scontext,
u32 *scontext_len);
-static int context_struct_compute_av(struct context *scontext,
- struct context *tcontext,
- u16 tclass,
- u32 requested,
- struct av_decision *avd);
+static void context_struct_compute_av(struct context *scontext,
+ struct context *tcontext,
+ u16 tclass,
+ struct av_decision *avd);
struct selinux_mapping {
u16 value; /* policy value */
@@ -196,23 +199,6 @@ static u16 unmap_class(u16 tclass)
return tclass;
}
-static u32 unmap_perm(u16 tclass, u32 tperm)
-{
- if (tclass < current_mapping_size) {
- unsigned i;
- u32 kperm = 0;
-
- for (i = 0; i < current_mapping[tclass].num_perms; i++)
- if (tperm & (1<<i)) {
- kperm |= current_mapping[tclass].perms[i];
- tperm &= ~(1<<i);
- }
- return kperm;
- }
-
- return tperm;
-}
-
static void map_decision(u16 tclass, struct av_decision *avd,
int allow_unknown)
{
@@ -250,6 +236,10 @@ static void map_decision(u16 tclass, struct av_decision *avd,
}
}
+int security_mls_enabled(void)
+{
+ return policydb.mls_enabled;
+}
/*
* Return the boolean value of a constraint expression
@@ -465,7 +455,8 @@ static void security_dump_masked_av(struct context *scontext,
char *scontext_name = NULL;
char *tcontext_name = NULL;
char *permission_names[32];
- int index, length;
+ int index;
+ u32 length;
bool need_comma = false;
if (!permissions)
@@ -532,7 +523,6 @@ out:
static void type_attribute_bounds_av(struct context *scontext,
struct context *tcontext,
u16 tclass,
- u32 requested,
struct av_decision *avd)
{
struct context lo_scontext;
@@ -553,7 +543,6 @@ static void type_attribute_bounds_av(struct context *scontext,
context_struct_compute_av(&lo_scontext,
tcontext,
tclass,
- requested,
&lo_avd);
if ((lo_avd.allowed & avd->allowed) == avd->allowed)
return; /* no masked permission */
@@ -569,7 +558,6 @@ static void type_attribute_bounds_av(struct context *scontext,
context_struct_compute_av(scontext,
&lo_tcontext,
tclass,
- requested,
&lo_avd);
if ((lo_avd.allowed & avd->allowed) == avd->allowed)
return; /* no masked permission */
@@ -586,7 +574,6 @@ static void type_attribute_bounds_av(struct context *scontext,
context_struct_compute_av(&lo_scontext,
&lo_tcontext,
tclass,
- requested,
&lo_avd);
if ((lo_avd.allowed & avd->allowed) == avd->allowed)
return; /* no masked permission */
@@ -607,11 +594,10 @@ static void type_attribute_bounds_av(struct context *scontext,
* Compute access vectors based on a context structure pair for
* the permissions in a particular class.
*/
-static int context_struct_compute_av(struct context *scontext,
- struct context *tcontext,
- u16 tclass,
- u32 requested,
- struct av_decision *avd)
+static void context_struct_compute_av(struct context *scontext,
+ struct context *tcontext,
+ u16 tclass,
+ struct av_decision *avd)
{
struct constraint_node *constraint;
struct role_allow *ra;
@@ -622,19 +608,14 @@ static int context_struct_compute_av(struct context *scontext,
struct ebitmap_node *snode, *tnode;
unsigned int i, j;
- /*
- * Initialize the access vectors to the default values.
- */
avd->allowed = 0;
avd->auditallow = 0;
avd->auditdeny = 0xffffffff;
- avd->seqno = latest_granting;
- avd->flags = 0;
if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
if (printk_ratelimit())
printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
- return -EINVAL;
+ return;
}
tclass_datum = policydb.class_val_to_struct[tclass - 1];
@@ -705,9 +686,7 @@ static int context_struct_compute_av(struct context *scontext,
* permission and notice it to userspace via audit.
*/
type_attribute_bounds_av(scontext, tcontext,
- tclass, requested, avd);
-
- return 0;
+ tclass, avd);
}
static int security_validtrans_handle_fail(struct context *ocontext,
@@ -864,7 +843,7 @@ int security_bounded_transition(u32 old_sid, u32 new_sid)
if (rc) {
char *old_name = NULL;
char *new_name = NULL;
- int length;
+ u32 length;
if (!context_struct_to_string(old_context,
&old_name, &length) &&
@@ -886,110 +865,116 @@ out:
return rc;
}
-
-static int security_compute_av_core(u32 ssid,
- u32 tsid,
- u16 tclass,
- u32 requested,
- struct av_decision *avd)
+static void avd_init(struct av_decision *avd)
{
- struct context *scontext = NULL, *tcontext = NULL;
- int rc = 0;
-
- scontext = sidtab_search(&sidtab, ssid);
- if (!scontext) {
- printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
- __func__, ssid);
- return -EINVAL;
- }
- tcontext = sidtab_search(&sidtab, tsid);
- if (!tcontext) {
- printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
- __func__, tsid);
- return -EINVAL;
- }
-
- rc = context_struct_compute_av(scontext, tcontext, tclass,
- requested, avd);
-
- /* permissive domain? */
- if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
- avd->flags |= AVD_FLAGS_PERMISSIVE;
-
- return rc;
+ avd->allowed = 0;
+ avd->auditallow = 0;
+ avd->auditdeny = 0xffffffff;
+ avd->seqno = latest_granting;
+ avd->flags = 0;
}
+
/**
* security_compute_av - Compute access vector decisions.
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
- * @requested: requested permissions
* @avd: access vector decisions
*
* Compute a set of access vector decisions based on the
* SID pair (@ssid, @tsid) for the permissions in @tclass.
- * Return -%EINVAL if any of the parameters are invalid or %0
- * if the access vector decisions were computed successfully.
*/
-int security_compute_av(u32 ssid,
- u32 tsid,
- u16 orig_tclass,
- u32 orig_requested,
- struct av_decision *avd)
+void security_compute_av(u32 ssid,
+ u32 tsid,
+ u16 orig_tclass,
+ struct av_decision *avd)
{
u16 tclass;
- u32 requested;
- int rc;
+ struct context *scontext = NULL, *tcontext = NULL;
read_lock(&policy_rwlock);
-
+ avd_init(avd);
if (!ss_initialized)
goto allow;
- requested = unmap_perm(orig_tclass, orig_requested);
+ scontext = sidtab_search(&sidtab, ssid);
+ if (!scontext) {
+ printk(KERN_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) {
+ printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
+ __func__, tsid);
+ goto out;
+ }
+
tclass = unmap_class(orig_tclass);
if (unlikely(orig_tclass && !tclass)) {
if (policydb.allow_unknown)
goto allow;
- rc = -EINVAL;
goto out;
}
- rc = security_compute_av_core(ssid, tsid, tclass, requested, avd);
+ context_struct_compute_av(scontext, tcontext, tclass, avd);
map_decision(orig_tclass, avd, policydb.allow_unknown);
out:
read_unlock(&policy_rwlock);
- return rc;
+ return;
allow:
avd->allowed = 0xffffffff;
- avd->auditallow = 0;
- avd->auditdeny = 0xffffffff;
- avd->seqno = latest_granting;
- avd->flags = 0;
- rc = 0;
goto out;
}
-int security_compute_av_user(u32 ssid,
- u32 tsid,
- u16 tclass,
- u32 requested,
- struct av_decision *avd)
+void security_compute_av_user(u32 ssid,
+ u32 tsid,
+ u16 tclass,
+ struct av_decision *avd)
{
- int rc;
+ struct context *scontext = NULL, *tcontext = NULL;
- if (!ss_initialized) {
- avd->allowed = 0xffffffff;
- avd->auditallow = 0;
- avd->auditdeny = 0xffffffff;
- avd->seqno = latest_granting;
- return 0;
+ read_lock(&policy_rwlock);
+ avd_init(avd);
+ if (!ss_initialized)
+ goto allow;
+
+ scontext = sidtab_search(&sidtab, ssid);
+ if (!scontext) {
+ printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
+ __func__, ssid);
+ goto out;
}
- read_lock(&policy_rwlock);
- rc = security_compute_av_core(ssid, tsid, tclass, requested, avd);
+ /* permissive domain? */
+ if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
+ avd->flags |= AVD_FLAGS_PERMISSIVE;
+
+ tcontext = sidtab_search(&sidtab, tsid);
+ if (!tcontext) {
+ printk(KERN_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(scontext, tcontext, tclass, avd);
+ out:
read_unlock(&policy_rwlock);
- return rc;
+ return;
+allow:
+ avd->allowed = 0xffffffff;
+ goto out;
}
/*
@@ -1565,7 +1550,10 @@ static int clone_sid(u32 sid,
{
struct sidtab *s = arg;
- return sidtab_insert(s, sid, context);
+ if (sid > SECINITSID_NUM)
+ return sidtab_insert(s, sid, context);
+ else
+ return 0;
}
static inline int convert_context_handle_invalid_context(struct context *context)
@@ -1606,12 +1594,17 @@ static int convert_context(u32 key,
{
struct convert_context_args *args;
struct context oldc;
+ struct ocontext *oc;
+ struct mls_range *range;
struct role_datum *role;
struct type_datum *typdatum;
struct user_datum *usrdatum;
char *s;
u32 len;
- int rc;
+ int rc = 0;
+
+ if (key <= SECINITSID_NUM)
+ goto out;
args = p;
@@ -1673,9 +1666,39 @@ static int convert_context(u32 key,
goto bad;
c->type = typdatum->value;
- rc = mls_convert_context(args->oldp, args->newp, c);
- if (rc)
- goto bad;
+ /* 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, c);
+ if (rc)
+ goto bad;
+ } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
+ /*
+ * Switching between MLS and non-MLS policy:
+ * free any storage used by the MLS fields in the
+ * context for all existing entries in the sidtab.
+ */
+ mls_context_destroy(c);
+ } 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) {
+ printk(KERN_ERR "SELinux: unable to look up"
+ " the initial SIDs list\n");
+ goto bad;
+ }
+ range = &oc->context[0].range;
+ rc = mls_range_set(c, range);
+ if (rc)
+ goto bad;
+ }
/* Check the validity of the new context. */
if (!policydb_context_isvalid(args->newp, c)) {
@@ -1771,9 +1794,17 @@ int security_load_policy(void *data, size_t len)
if (policydb_read(&newpolicydb, fp))
return -EINVAL;
- if (sidtab_init(&newsidtab)) {
+ /* If switching between different policy types, log MLS status */
+ if (policydb.mls_enabled && !newpolicydb.mls_enabled)
+ printk(KERN_INFO "SELinux: Disabling MLS support...\n");
+ else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
+ printk(KERN_INFO "SELinux: Enabling MLS support...\n");
+
+ rc = policydb_load_isids(&newpolicydb, &newsidtab);
+ if (rc) {
+ printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
policydb_destroy(&newpolicydb);
- return -ENOMEM;
+ return rc;
}
if (selinux_set_mapping(&newpolicydb, secclass_map,
@@ -1800,8 +1831,12 @@ int security_load_policy(void *data, size_t len)
args.oldp = &policydb;
args.newp = &newpolicydb;
rc = sidtab_map(&newsidtab, convert_context, &args);
- if (rc)
+ if (rc) {
+ printk(KERN_ERR "SELinux: unable to convert the internal"
+ " representation of contexts in the new SID"
+ " table\n");
goto err;
+ }
/* Save the old policydb and SID table to free later. */
memcpy(&oldpolicydb, &policydb, sizeof policydb);
@@ -2397,7 +2432,7 @@ int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
u32 len;
int rc = 0;
- if (!ss_initialized || !selinux_mls_enabled) {
+ if (!ss_initialized || !policydb.mls_enabled) {
*new_sid = sid;
goto out;
}
@@ -2498,7 +2533,7 @@ int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
/* we don't need to check ss_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 ss_initialized was true */
- if (!selinux_mls_enabled) {
+ if (!policydb.mls_enabled) {
*peer_sid = SECSID_NULL;
return 0;
}
@@ -2555,7 +2590,7 @@ int security_get_classes(char ***classes, int *nclasses)
read_lock(&policy_rwlock);
*nclasses = policydb.p_classes.nprim;
- *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
+ *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
if (!*classes)
goto out;
@@ -2602,7 +2637,7 @@ int security_get_permissions(char *class, char ***perms, int *nperms)
}
*nperms = match->permissions.nprim;
- *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
+ *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
if (!*perms)
goto out;
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