selinux: move context hashing under sidtab

Now that context hash computation no longer depends on policydb, we can
simplify things by moving the context hashing completely under sidtab.
The hash is still cached in sidtab entries, but not for the in-flight
context structures.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 26 insertions, 33 deletions

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index ed3306914309..b49a336b1e6e 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1490,17 +1490,6 @@ out:
 	return rc;
 }
 
-static int context_struct_to_sid(struct selinux_state *state,
-				 struct context *context, u32 *sid)
-{
-	struct sidtab *sidtab = state->ss->sidtab;
-
-	if (!context->hash)
-		context_add_hash(context);
-
-	return sidtab_context_to_sid(sidtab, context, sid);
-}
-
 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,
@@ -1555,7 +1544,7 @@ static int security_context_to_sid_core(struct selinux_state *state,
 		str = NULL;
 	} else if (rc)
 		goto out_unlock;
-	rc = context_struct_to_sid(state, &context, sid);
+	rc = sidtab_context_to_sid(sidtab, &context, sid);
 	context_destroy(&context);
 out_unlock:
 	read_unlock(&state->ss->policy_rwlock);
@@ -1865,7 +1854,7 @@ static int security_compute_sid(struct selinux_state *state,
 			goto out_unlock;
 	}
 	/* Obtain the sid for the context. */
-	rc = context_struct_to_sid(state, &newcontext, out_sid);
+	rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
 out_unlock:
 	read_unlock(&state->ss->policy_rwlock);
 	context_destroy(&newcontext);
@@ -2017,7 +2006,6 @@ static int convert_context(struct context *oldc, struct context *newc, void *p)
 			context_init(newc);
 			newc->str = s;
 			newc->len = oldc->len;
-			newc->hash = oldc->hash;
 			return 0;
 		}
 		kfree(s);
@@ -2094,8 +2082,6 @@ static int convert_context(struct context *oldc, struct context *newc, void *p)
 			goto bad;
 	}
 
-	context_add_hash(newc);
-
 	return 0;
 bad:
 	/* Map old representation to string and save it. */
@@ -2105,7 +2091,6 @@ bad:
 	context_destroy(newc);
 	newc->str = s;
 	newc->len = len;
-	context_add_hash(newc);
 	pr_info("SELinux:  Context %s became invalid (unmapped).\n",
 		newc->str);
 	return 0;
@@ -2322,12 +2307,14 @@ int security_port_sid(struct selinux_state *state,
 		      u8 protocol, u16 port, u32 *out_sid)
 {
 	struct policydb *policydb;
+	struct sidtab *sidtab;
 	struct ocontext *c;
 	int rc = 0;
 
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_PORT];
 	while (c) {
@@ -2340,7 +2327,7 @@ int security_port_sid(struct selinux_state *state,
 
 	if (c) {
 		if (!c->sid[0]) {
-			rc = context_struct_to_sid(state, &c->context[0],
+			rc = sidtab_context_to_sid(sidtab, &c->context[0],
 						   &c->sid[0]);
 			if (rc)
 				goto out;
@@ -2365,12 +2352,14 @@ int security_ib_pkey_sid(struct selinux_state *state,
 			 u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
 {
 	struct policydb *policydb;
+	struct sidtab *sidtab;
 	struct ocontext *c;
 	int rc = 0;
 
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_IBPKEY];
 	while (c) {
@@ -2384,7 +2373,7 @@ int security_ib_pkey_sid(struct selinux_state *state,
 
 	if (c) {
 		if (!c->sid[0]) {
-			rc = context_struct_to_sid(state,
+			rc = sidtab_context_to_sid(sidtab,
 						   &c->context[0],
 						   &c->sid[0]);
 			if (rc)
@@ -2409,12 +2398,14 @@ int security_ib_endport_sid(struct selinux_state *state,
 			    const char *dev_name, u8 port_num, u32 *out_sid)
 {
 	struct policydb *policydb;
+	struct sidtab *sidtab;
 	struct ocontext *c;
 	int rc = 0;
 
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_IBENDPORT];
 	while (c) {
@@ -2429,7 +2420,7 @@ int security_ib_endport_sid(struct selinux_state *state,
 
 	if (c) {
 		if (!c->sid[0]) {
-			rc = context_struct_to_sid(state, &c->context[0],
+			rc = sidtab_context_to_sid(sidtab, &c->context[0],
 						   &c->sid[0]);
 			if (rc)
 				goto out;
@@ -2452,12 +2443,14 @@ int security_netif_sid(struct selinux_state *state,
 		       char *name, u32 *if_sid)
 {
 	struct policydb *policydb;
+	struct sidtab *sidtab;
 	int rc = 0;
 	struct ocontext *c;
 
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_NETIF];
 	while (c) {
@@ -2468,11 +2461,11 @@ int security_netif_sid(struct selinux_state *state,
 
 	if (c) {
 		if (!c->sid[0] || !c->sid[1]) {
-			rc = context_struct_to_sid(state, &c->context[0],
+			rc = sidtab_context_to_sid(sidtab, &c->context[0],
 						   &c->sid[0]);
 			if (rc)
 				goto out;
-			rc = context_struct_to_sid(state, &c->context[1],
+			rc = sidtab_context_to_sid(sidtab, &c->context[1],
 						   &c->sid[1]);
 			if (rc)
 				goto out;
@@ -2513,12 +2506,14 @@ int security_node_sid(struct selinux_state *state,
 		      u32 *out_sid)
 {
 	struct policydb *policydb;
+	struct sidtab *sidtab;
 	int rc;
 	struct ocontext *c;
 
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
+	sidtab = state->ss->sidtab;
 
 	switch (domain) {
 	case AF_INET: {
@@ -2560,7 +2555,7 @@ int security_node_sid(struct selinux_state *state,
 
 	if (c) {
 		if (!c->sid[0]) {
-			rc = context_struct_to_sid(state,
+			rc = sidtab_context_to_sid(sidtab,
 						   &c->context[0],
 						   &c->sid[0]);
 			if (rc)
@@ -2644,17 +2639,12 @@ int security_get_user_sids(struct selinux_state *state,
 		usercon.role = i + 1;
 		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
 			usercon.type = j + 1;
-			/*
-			 * The same context struct is reused here so the hash
-			 * must be reset.
-			 */
-			usercon.hash = 0;
 
 			if (mls_setup_user_range(policydb, fromcon, user,
 						 &usercon))
 				continue;
 
-			rc = context_struct_to_sid(state, &usercon, &sid);
+			rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
 			if (rc)
 				goto out_unlock;
 			if (mynel < maxnel) {
@@ -2725,6 +2715,7 @@ static inline int __security_genfs_sid(struct selinux_state *state,
 				       u32 *sid)
 {
 	struct policydb *policydb = &state->ss->policydb;
+	struct sidtab *sidtab = state->ss->sidtab;
 	int len;
 	u16 sclass;
 	struct genfs *genfs;
@@ -2759,7 +2750,7 @@ static inline int __security_genfs_sid(struct selinux_state *state,
 		goto out;
 
 	if (!c->sid[0]) {
-		rc = context_struct_to_sid(state, &c->context[0], &c->sid[0]);
+		rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]);
 		if (rc)
 			goto out;
 	}
@@ -2801,6 +2792,7 @@ int security_genfs_sid(struct selinux_state *state,
 int security_fs_use(struct selinux_state *state, struct super_block *sb)
 {
 	struct policydb *policydb;
+	struct sidtab *sidtab;
 	int rc = 0;
 	struct ocontext *c;
 	struct superblock_security_struct *sbsec = sb->s_security;
@@ -2809,6 +2801,7 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb)
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_FSUSE];
 	while (c) {
@@ -2820,7 +2813,7 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb)
 	if (c) {
 		sbsec->behavior = c->v.behavior;
 		if (!c->sid[0]) {
-			rc = context_struct_to_sid(state, &c->context[0],
+			rc = sidtab_context_to_sid(sidtab, &c->context[0],
 						   &c->sid[0]);
 			if (rc)
 				goto out;
@@ -3068,7 +3061,7 @@ int security_sid_mls_copy(struct selinux_state *state,
 			goto out_unlock;
 		}
 	}
-	rc = context_struct_to_sid(state, &newcon, new_sid);
+	rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
 out_unlock:
 	read_unlock(&state->ss->policy_rwlock);
 	context_destroy(&newcon);
@@ -3661,7 +3654,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
 		if (!mls_context_isvalid(policydb, &ctx_new))
 			goto out_free;
 
-		rc = context_struct_to_sid(state, &ctx_new, sid);
+		rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
 		if (rc)
 			goto out_free;