selinux: treat atomic flags more carefully

The disabled/enforcing/initialized flags are all accessed concurrently
by threads so use the appropriate accessors that ensure atomicity and
document that it is expected.

Use smp_load/acquire...() helpers (with memory barriers) for the
initialized flag, since it gates access to the rest of the state
structures.

Note that the disabled flag is currently not used for anything other
than avoiding double disable, but it will be used for bailing out of
hooks once security_delete_hooks() is removed.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 19 insertions, 19 deletions

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 55cf42945cba..0e8b94e8e156 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -767,7 +767,7 @@ static int security_compute_validatetrans(struct selinux_state *state,
 	int rc = 0;
 
 
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		return 0;
 
 	read_lock(&state->ss->policy_rwlock);
@@ -868,7 +868,7 @@ int security_bounded_transition(struct selinux_state *state,
 	int index;
 	int rc;
 
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		return 0;
 
 	read_lock(&state->ss->policy_rwlock);
@@ -1027,7 +1027,7 @@ void security_compute_xperms_decision(struct selinux_state *state,
 	memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
 
 	read_lock(&state->ss->policy_rwlock);
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		goto allow;
 
 	policydb = &state->ss->policydb;
@@ -1112,7 +1112,7 @@ void security_compute_av(struct selinux_state *state,
 	read_lock(&state->ss->policy_rwlock);
 	avd_init(state, avd);
 	xperms->len = 0;
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		goto allow;
 
 	policydb = &state->ss->policydb;
@@ -1166,7 +1166,7 @@ void security_compute_av_user(struct selinux_state *state,
 
 	read_lock(&state->ss->policy_rwlock);
 	avd_init(state, avd);
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		goto allow;
 
 	policydb = &state->ss->policydb;
@@ -1286,7 +1286,7 @@ int security_sidtab_hash_stats(struct selinux_state *state, char *page)
 {
 	int rc;
 
-	if (!state->initialized) {
+	if (!selinux_initialized(state)) {
 		pr_err("SELinux: %s:  called before initial load_policy\n",
 		       __func__);
 		return -EINVAL;
@@ -1320,7 +1320,7 @@ static int security_sid_to_context_core(struct selinux_state *state,
 		*scontext = NULL;
 	*scontext_len  = 0;
 
-	if (!state->initialized) {
+	if (!selinux_initialized(state)) {
 		if (sid <= SECINITSID_NUM) {
 			char *scontextp;
 
@@ -1549,7 +1549,7 @@ static int security_context_to_sid_core(struct selinux_state *state,
 	if (!scontext2)
 		return -ENOMEM;
 
-	if (!state->initialized) {
+	if (!selinux_initialized(state)) {
 		int i;
 
 		for (i = 1; i < SECINITSID_NUM; i++) {
@@ -1736,7 +1736,7 @@ static int security_compute_sid(struct selinux_state *state,
 	int rc = 0;
 	bool sock;
 
-	if (!state->initialized) {
+	if (!selinux_initialized(state)) {
 		switch (orig_tclass) {
 		case SECCLASS_PROCESS: /* kernel value */
 			*out_sid = ssid;
@@ -2198,7 +2198,7 @@ int security_load_policy(struct selinux_state *state, void *data, size_t len)
 		goto out;
 	}
 
-	if (!state->initialized) {
+	if (!selinux_initialized(state)) {
 		rc = policydb_read(policydb, fp);
 		if (rc) {
 			kfree(newsidtab);
@@ -2223,7 +2223,7 @@ int security_load_policy(struct selinux_state *state, void *data, size_t len)
 
 		state->ss->sidtab = newsidtab;
 		security_load_policycaps(state);
-		state->initialized = 1;
+		selinux_mark_initialized(state);
 		seqno = ++state->ss->latest_granting;
 		selinux_complete_init();
 		avc_ss_reset(state->avc, seqno);
@@ -2639,7 +2639,7 @@ int security_get_user_sids(struct selinux_state *state,
 	*sids = NULL;
 	*nel = 0;
 
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		goto out;
 
 	read_lock(&state->ss->policy_rwlock);
@@ -2875,7 +2875,7 @@ int security_get_bools(struct selinux_state *state,
 	struct policydb *policydb;
 	int i, rc;
 
-	if (!state->initialized) {
+	if (!selinux_initialized(state)) {
 		*len = 0;
 		*names = NULL;
 		*values = NULL;
@@ -3050,7 +3050,7 @@ int security_sid_mls_copy(struct selinux_state *state,
 	int rc;
 
 	rc = 0;
-	if (!state->initialized || !policydb->mls_enabled) {
+	if (!selinux_initialized(state) || !policydb->mls_enabled) {
 		*new_sid = sid;
 		goto out;
 	}
@@ -3217,7 +3217,7 @@ int security_get_classes(struct selinux_state *state,
 	struct policydb *policydb = &state->ss->policydb;
 	int rc;
 
-	if (!state->initialized) {
+	if (!selinux_initialized(state)) {
 		*nclasses = 0;
 		*classes = NULL;
 		return 0;
@@ -3366,7 +3366,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 
 	*rule = NULL;
 
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		return -EOPNOTSUPP;
 
 	switch (field) {
@@ -3665,7 +3665,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
 	struct context *ctx;
 	struct context ctx_new;
 
-	if (!state->initialized) {
+	if (!selinux_initialized(state)) {
 		*sid = SECSID_NULL;
 		return 0;
 	}
@@ -3732,7 +3732,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
 	int rc;
 	struct context *ctx;
 
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		return 0;
 
 	read_lock(&state->ss->policy_rwlock);
@@ -3771,7 +3771,7 @@ int security_read_policy(struct selinux_state *state,
 	int rc;
 	struct policy_file fp;
 
-	if (!state->initialized)
+	if (!selinux_initialized(state))
 		return -EINVAL;
 
 	*len = security_policydb_len(state);