5 files changed, 142 insertions, 16 deletions

diff --git a/security/selinux/ss/context.h b/security/selinux/ss/context.h
index 45e8fb0515f8..212e3479a0d9 100644
--- a/security/selinux/ss/context.h
+++ b/security/selinux/ss/context.h
@@ -74,6 +74,26 @@ out:
 	return rc;
 }
 
+/*
+ * Sets both levels in the MLS range of 'dst' to the high level of 'src'.
+ */
+static inline int mls_context_cpy_high(struct context *dst, struct context *src)
+{
+	int rc;
+
+	dst->range.level[0].sens = src->range.level[1].sens;
+	rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[1].cat);
+	if (rc)
+		goto out;
+
+	dst->range.level[1].sens = src->range.level[1].sens;
+	rc = ebitmap_cpy(&dst->range.level[1].cat, &src->range.level[1].cat);
+	if (rc)
+		ebitmap_destroy(&dst->range.level[0].cat);
+out:
+	return rc;
+}
+
 static inline int mls_context_cmp(struct context *c1, struct context *c2)
 {
 	return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index fbf9c5816c71..40de8d3f208e 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -517,6 +517,8 @@ int mls_compute_sid(struct context *scontext,
 {
 	struct range_trans rtr;
 	struct mls_range *r;
+	struct class_datum *cladatum;
+	int default_range = 0;
 
 	if (!policydb.mls_enabled)
 		return 0;
@@ -530,6 +532,28 @@ int mls_compute_sid(struct context *scontext,
 		r = hashtab_search(policydb.range_tr, &rtr);
 		if (r)
 			return mls_range_set(newcontext, r);
+
+		if (tclass && tclass <= policydb.p_classes.nprim) {
+			cladatum = policydb.class_val_to_struct[tclass - 1];
+			if (cladatum)
+				default_range = cladatum->default_range;
+		}
+
+		switch (default_range) {
+		case DEFAULT_SOURCE_LOW:
+			return mls_context_cpy_low(newcontext, scontext);
+		case DEFAULT_SOURCE_HIGH:
+			return mls_context_cpy_high(newcontext, scontext);
+		case DEFAULT_SOURCE_LOW_HIGH:
+			return mls_context_cpy(newcontext, scontext);
+		case DEFAULT_TARGET_LOW:
+			return mls_context_cpy_low(newcontext, tcontext);
+		case DEFAULT_TARGET_HIGH:
+			return mls_context_cpy_high(newcontext, tcontext);
+		case DEFAULT_TARGET_LOW_HIGH:
+			return mls_context_cpy(newcontext, tcontext);
+		}
+
 		/* Fallthrough */
 	case AVTAB_CHANGE:
 		if ((tclass == policydb.process_class) || (sock == true))
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index a7f61d52f05c..9cd9b7c661ec 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -133,6 +133,16 @@ static struct policydb_compat_info policydb_compat[] = {
 		.sym_num	= SYM_NUM,
 		.ocon_num	= OCON_NUM,
 	},
+	{
+		.version	= POLICYDB_VERSION_NEW_OBJECT_DEFAULTS,
+		.sym_num	= SYM_NUM,
+		.ocon_num	= OCON_NUM,
+	},
+	{
+		.version	= POLICYDB_VERSION_DEFAULT_TYPE,
+		.sym_num	= SYM_NUM,
+		.ocon_num	= OCON_NUM,
+	},
 };
 
 static struct policydb_compat_info *policydb_lookup_compat(int version)
@@ -1306,6 +1316,23 @@ static int class_read(struct policydb *p, struct hashtab *h, void *fp)
 			goto bad;
 	}
 
+	if (p->policyvers >= POLICYDB_VERSION_NEW_OBJECT_DEFAULTS) {
+		rc = next_entry(buf, fp, sizeof(u32) * 3);
+		if (rc)
+			goto bad;
+
+		cladatum->default_user = le32_to_cpu(buf[0]);
+		cladatum->default_role = le32_to_cpu(buf[1]);
+		cladatum->default_range = le32_to_cpu(buf[2]);
+	}
+
+	if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) {
+		rc = next_entry(buf, fp, sizeof(u32) * 1);
+		if (rc)
+			goto bad;
+		cladatum->default_type = le32_to_cpu(buf[0]);
+	}
+
 	rc = hashtab_insert(h, key, cladatum);
 	if (rc)
 		goto bad;
@@ -2832,6 +2859,23 @@ static int class_write(void *vkey, void *datum, void *ptr)
 	if (rc)
 		return rc;
 
+	if (p->policyvers >= POLICYDB_VERSION_NEW_OBJECT_DEFAULTS) {
+		buf[0] = cpu_to_le32(cladatum->default_user);
+		buf[1] = cpu_to_le32(cladatum->default_role);
+		buf[2] = cpu_to_le32(cladatum->default_range);
+
+		rc = put_entry(buf, sizeof(uint32_t), 3, fp);
+		if (rc)
+			return rc;
+	}
+
+	if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) {
+		buf[0] = cpu_to_le32(cladatum->default_type);
+		rc = put_entry(buf, sizeof(uint32_t), 1, fp);
+		if (rc)
+			return rc;
+	}
+
 	return 0;
 }
 
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index b846c0387180..da637471d4ce 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -60,6 +60,20 @@ struct class_datum {
 	struct symtab permissions;	/* class-specific permission symbol table */
 	struct constraint_node *constraints;	/* constraints on class permissions */
 	struct constraint_node *validatetrans;	/* special transition rules */
+/* Options how a new object user, role, and type should be decided */
+#define DEFAULT_SOURCE         1
+#define DEFAULT_TARGET         2
+	char default_user;
+	char default_role;
+	char default_type;
+/* Options how a new object range should be decided */
+#define DEFAULT_SOURCE_LOW     1
+#define DEFAULT_SOURCE_HIGH    2
+#define DEFAULT_SOURCE_LOW_HIGH        3
+#define DEFAULT_TARGET_LOW     4
+#define DEFAULT_TARGET_HIGH    5
+#define DEFAULT_TARGET_LOW_HIGH        6
+	char default_range;
 };
 
 /* Role attributes */
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 185f849a26f6..4321b8fc8863 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1018,9 +1018,11 @@ static int context_struct_to_string(struct context *context, char **scontext, u3
 
 	if (context->len) {
 		*scontext_len = context->len;
-		*scontext = kstrdup(context->str, GFP_ATOMIC);
-		if (!(*scontext))
-			return -ENOMEM;
+		if (scontext) {
+			*scontext = kstrdup(context->str, GFP_ATOMIC);
+			if (!(*scontext))
+				return -ENOMEM;
+		}
 		return 0;
 	}
 
@@ -1389,6 +1391,7 @@ static int security_compute_sid(u32 ssid,
 				u32 *out_sid,
 				bool kern)
 {
+	struct class_datum *cladatum = NULL;
 	struct context *scontext = NULL, *tcontext = NULL, newcontext;
 	struct role_trans *roletr = NULL;
 	struct avtab_key avkey;
@@ -1437,12 +1440,20 @@ static int security_compute_sid(u32 ssid,
 		goto out_unlock;
 	}
 
+	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:
-		/* Use the process user identity. */
-		newcontext.user = scontext->user;
+		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. */
@@ -1450,16 +1461,31 @@ static int security_compute_sid(u32 ssid,
 		break;
 	}
 
-	/* Set the role and type to default values. */
-	if ((tclass == policydb.process_class) || (sock == true)) {
-		/* Use the current role and type of process. */
+	/* Set the role to default values. */
+	if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
 		newcontext.role = scontext->role;
-		newcontext.type = scontext->type;
+	} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
+		newcontext.role = tcontext->role;
 	} else {
-		/* Use the well-defined object role. */
-		newcontext.role = OBJECT_R_VAL;
-		/* Use the type of the related object. */
+		if ((tclass == policydb.process_class) || (sock == true))
+			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 == true)) {
+			/* 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. */
@@ -3018,8 +3044,7 @@ out:
 
 static int (*aurule_callback)(void) = audit_update_lsm_rules;
 
-static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
-			       u16 class, u32 perms, u32 *retained)
+static int aurule_avc_callback(u32 event)
 {
 	int err = 0;
 
@@ -3032,8 +3057,7 @@ static int __init aurule_init(void)
 {
 	int err;
 
-	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
-			       SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
+	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
 	if (err)
 		panic("avc_add_callback() failed, error %d\n", err);