Merge branch 'for-2.6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6

* 'for-2.6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
  SELinux: validate kernel object classes and permissions
  SELinux: ensure keys constant in hashtab_search
  SELinux: export object class and permission definitions
  SELinux: remove current object class and permission validation mechanism

6 files changed, 171 insertions, 103 deletions

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index a300702..74c0319 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -32,12 +32,7 @@
 #include "avc.h"
 #include "avc_ss.h"
 
-static const struct av_perm_to_string
-{
-  u16 tclass;
-  u32 value;
-  const char *name;
-} av_perm_to_string[] = {
+static const struct av_perm_to_string av_perm_to_string[] = {
 #define S_(c, v, s) { c, v, s },
 #include "av_perm_to_string.h"
 #undef S_
@@ -57,17 +52,21 @@ static const char *class_to_string[] = {
 #undef TE_
 #undef S_
 
-static const struct av_inherit
-{
-    u16 tclass;
-    const char **common_pts;
-    u32 common_base;
-} av_inherit[] = {
+static const struct av_inherit av_inherit[] = {
 #define S_(c, i, b) { c, common_##i##_perm_to_string, b },
 #include "av_inherit.h"
 #undef S_
 };
 
+const struct selinux_class_perm selinux_class_perm = {
+	av_perm_to_string,
+	ARRAY_SIZE(av_perm_to_string),
+	class_to_string,
+	ARRAY_SIZE(class_to_string),
+	av_inherit,
+	ARRAY_SIZE(av_inherit)
+};
+
 #define AVC_CACHE_SLOTS			512
 #define AVC_DEF_CACHE_THRESHOLD		512
 #define AVC_CACHE_RECLAIM		16
diff --git a/security/selinux/include/avc_ss.h b/security/selinux/include/avc_ss.h
index 450a283..ff869e8 100644
--- a/security/selinux/include/avc_ss.h
+++ b/security/selinux/include/avc_ss.h
@@ -10,5 +10,29 @@
 
 int avc_ss_reset(u32 seqno);
 
+struct av_perm_to_string
+{
+	u16 tclass;
+	u32 value;
+	const char *name;
+};
+
+struct av_inherit
+{
+	u16 tclass;
+	const char **common_pts;
+	u32 common_base;
+};
+
+struct selinux_class_perm
+{
+	const struct av_perm_to_string *av_perm_to_string;
+	u32 av_pts_len;
+	const char **class_to_string;
+	u32 cts_len;
+	const struct av_inherit *av_inherit;
+	u32 av_inherit_len;
+};
+
 #endif /* _SELINUX_AVC_SS_H_ */
 
diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c
index 24e5ec9..77b530c 100644
--- a/security/selinux/ss/hashtab.c
+++ b/security/selinux/ss/hashtab.c
@@ -8,8 +8,8 @@
 #include <linux/errno.h>
 #include "hashtab.h"
 
-struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, void *key),
-                               int (*keycmp)(struct hashtab *h, void *key1, void *key2),
+struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key),
+                               int (*keycmp)(struct hashtab *h, const void *key1, const void *key2),
                                u32 size)
 {
 	struct hashtab *p;
@@ -71,7 +71,7 @@ int hashtab_insert(struct hashtab *h, void *key, void *datum)
 	return 0;
 }
 
-void *hashtab_search(struct hashtab *h, void *key)
+void *hashtab_search(struct hashtab *h, const void *key)
 {
 	u32 hvalue;
 	struct hashtab_node *cur;
diff --git a/security/selinux/ss/hashtab.h b/security/selinux/ss/hashtab.h
index 4cc8581..7e2ff3e 100644
--- a/security/selinux/ss/hashtab.h
+++ b/security/selinux/ss/hashtab.h
@@ -22,9 +22,9 @@ struct hashtab {
 	struct hashtab_node **htable;	/* hash table */
 	u32 size;			/* number of slots in hash table */
 	u32 nel;			/* number of elements in hash table */
-	u32 (*hash_value)(struct hashtab *h, void *key);
+	u32 (*hash_value)(struct hashtab *h, const void *key);
 					/* hash function */
-	int (*keycmp)(struct hashtab *h, void *key1, void *key2);
+	int (*keycmp)(struct hashtab *h, const void *key1, const void *key2);
 					/* key comparison function */
 };
 
@@ -39,8 +39,8 @@ struct hashtab_info {
  * Returns NULL if insufficent space is available or
  * the new hash table otherwise.
  */
-struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, void *key),
-                               int (*keycmp)(struct hashtab *h, void *key1, void *key2),
+struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key),
+                               int (*keycmp)(struct hashtab *h, const void *key1, const void *key2),
                                u32 size);
 
 /*
@@ -59,7 +59,7 @@ int hashtab_insert(struct hashtab *h, void *k, void *d);
  * Returns NULL if no entry has the specified key or
  * the datum of the entry otherwise.
  */
-void *hashtab_search(struct hashtab *h, void *k);
+void *hashtab_search(struct hashtab *h, const void *k);
 
 /*
  * Destroys the specified hash table.
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index bfe1227..4088204 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -17,9 +17,13 @@
  *
  *      Added support for NetLabel
  *
+ * Updated: Chad Sellers <csellers@tresys.com>
+ *
+ *  Added validation of kernel classes and permissions
+ *
  * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
- * Copyright (C) 2003 - 2004 Tresys Technology, LLC
+ * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  *	This program is free software; you can redistribute it and/or modify
  *  	it under the terms of the GNU General Public License as published by
@@ -53,6 +57,11 @@
 extern void selnl_notify_policyload(u32 seqno);
 unsigned int policydb_loaded_version;
 
+/*
+ * This is declared in avc.c
+ */
+extern const struct selinux_class_perm selinux_class_perm;
+
 static DEFINE_RWLOCK(policy_rwlock);
 #define POLICY_RDLOCK read_lock(&policy_rwlock)
 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
@@ -1019,86 +1028,112 @@ int security_change_sid(u32 ssid,
 }
 
 /*
- * Verify that each permission that is defined under the
- * existing policy is still defined with the same value
- * in the new policy.
+ * Verify that each kernel class that is defined in the
+ * policy is correct
  */
-static int validate_perm(void *key, void *datum, void *p)
+static int validate_classes(struct policydb *p)
 {
-	struct hashtab *h;
-	struct perm_datum *perdatum, *perdatum2;
-	int rc = 0;
-
-
-	h = p;
-	perdatum = datum;
-
-	perdatum2 = hashtab_search(h, key);
-	if (!perdatum2) {
-		printk(KERN_ERR "security:  permission %s disappeared",
-		       (char *)key);
-		rc = -ENOENT;
-		goto out;
-	}
-	if (perdatum->value != perdatum2->value) {
-		printk(KERN_ERR "security:  the value of permission %s changed",
-		       (char *)key);
-		rc = -EINVAL;
-	}
-out:
-	return rc;
-}
-
-/*
- * Verify that each class that is defined under the
- * existing policy is still defined with the same
- * attributes in the new policy.
- */
-static int validate_class(void *key, void *datum, void *p)
-{
-	struct policydb *newp;
-	struct class_datum *cladatum, *cladatum2;
-	int rc;
-
-	newp = p;
-	cladatum = datum;
-
-	cladatum2 = hashtab_search(newp->p_classes.table, key);
-	if (!cladatum2) {
-		printk(KERN_ERR "security:  class %s disappeared\n",
-		       (char *)key);
-		rc = -ENOENT;
-		goto out;
-	}
-	if (cladatum->value != cladatum2->value) {
-		printk(KERN_ERR "security:  the value of class %s changed\n",
-		       (char *)key);
-		rc = -EINVAL;
-		goto out;
+	int i, j;
+	struct class_datum *cladatum;
+	struct perm_datum *perdatum;
+	u32 nprim, tmp, common_pts_len, perm_val, pol_val;
+	u16 class_val;
+	const struct selinux_class_perm *kdefs = &selinux_class_perm;
+	const char *def_class, *def_perm, *pol_class;
+	struct symtab *perms;
+
+	for (i = 1; i < kdefs->cts_len; i++) {
+		def_class = kdefs->class_to_string[i];
+		if (i > p->p_classes.nprim) {
+			printk(KERN_INFO
+			       "security:  class %s not defined in policy\n",
+			       def_class);
+			continue;
+		}
+		pol_class = p->p_class_val_to_name[i-1];
+		if (strcmp(pol_class, def_class)) {
+			printk(KERN_ERR
+			       "security:  class %d is incorrect, found %s but should be %s\n",
+			       i, pol_class, def_class);
+			return -EINVAL;
+		}
 	}
-	if ((cladatum->comdatum && !cladatum2->comdatum) ||
-	    (!cladatum->comdatum && cladatum2->comdatum)) {
-		printk(KERN_ERR "security:  the inherits clause for the access "
-		       "vector definition for class %s changed\n", (char *)key);
-		rc = -EINVAL;
-		goto out;
+	for (i = 0; i < kdefs->av_pts_len; i++) {
+		class_val = kdefs->av_perm_to_string[i].tclass;
+		perm_val = kdefs->av_perm_to_string[i].value;
+		def_perm = kdefs->av_perm_to_string[i].name;
+		if (class_val > p->p_classes.nprim)
+			continue;
+		pol_class = p->p_class_val_to_name[class_val-1];
+		cladatum = hashtab_search(p->p_classes.table, pol_class);
+		BUG_ON(!cladatum);
+		perms = &cladatum->permissions;
+		nprim = 1 << (perms->nprim - 1);
+		if (perm_val > nprim) {
+			printk(KERN_INFO
+			       "security:  permission %s in class %s not defined in policy\n",
+			       def_perm, pol_class);
+			continue;
+		}
+		perdatum = hashtab_search(perms->table, def_perm);
+		if (perdatum == NULL) {
+			printk(KERN_ERR
+			       "security:  permission %s in class %s not found in policy\n",
+			       def_perm, pol_class);
+			return -EINVAL;
+		}
+		pol_val = 1 << (perdatum->value - 1);
+		if (pol_val != perm_val) {
+			printk(KERN_ERR
+			       "security:  permission %s in class %s has incorrect value\n",
+			       def_perm, pol_class);
+			return -EINVAL;
+		}
 	}
-	if (cladatum->comdatum) {
-		rc = hashtab_map(cladatum->comdatum->permissions.table, validate_perm,
-		                 cladatum2->comdatum->permissions.table);
-		if (rc) {
-			printk(" in the access vector definition for class "
-			       "%s\n", (char *)key);
-			goto out;
+	for (i = 0; i < kdefs->av_inherit_len; i++) {
+		class_val = kdefs->av_inherit[i].tclass;
+		if (class_val > p->p_classes.nprim)
+			continue;
+		pol_class = p->p_class_val_to_name[class_val-1];
+		cladatum = hashtab_search(p->p_classes.table, pol_class);
+		BUG_ON(!cladatum);
+		if (!cladatum->comdatum) {
+			printk(KERN_ERR
+			       "security:  class %s should have an inherits clause but does not\n",
+			       pol_class);
+			return -EINVAL;
+		}
+		tmp = kdefs->av_inherit[i].common_base;
+		common_pts_len = 0;
+		while (!(tmp & 0x01)) {
+			common_pts_len++;
+			tmp >>= 1;
+		}
+		perms = &cladatum->comdatum->permissions;
+		for (j = 0; j < common_pts_len; j++) {
+			def_perm = kdefs->av_inherit[i].common_pts[j];
+			if (j >= perms->nprim) {
+				printk(KERN_INFO
+				       "security:  permission %s in class %s not defined in policy\n",
+				       def_perm, pol_class);
+				continue;
+			}
+			perdatum = hashtab_search(perms->table, def_perm);
+			if (perdatum == NULL) {
+				printk(KERN_ERR
+				       "security:  permission %s in class %s not found in policy\n",
+				       def_perm, pol_class);
+				return -EINVAL;
+			}
+			if (perdatum->value != j + 1) {
+				printk(KERN_ERR
+				       "security:  permission %s in class %s has incorrect value\n",
+				       def_perm, pol_class);
+				return -EINVAL;
+			}
 		}
 	}
-	rc = hashtab_map(cladatum->permissions.table, validate_perm,
-	                 cladatum2->permissions.table);
-	if (rc)
-		printk(" in access vector definition for class %s\n",
-		       (char *)key);
-out:
-	return rc;
+	return 0;
 }
 
 /* Clone the SID into the new SID table. */
@@ -1243,6 +1278,16 @@ int security_load_policy(void *data, size_t len)
 			avtab_cache_destroy();
 			return -EINVAL;
 		}
+		/* Verify that the kernel defined classes are correct. */
+		if (validate_classes(&policydb)) {
+			printk(KERN_ERR
+			       "security:  the definition of a class is incorrect\n");
+			LOAD_UNLOCK;
+			sidtab_destroy(&sidtab);
+			policydb_destroy(&policydb);
+			avtab_cache_destroy();
+			return -EINVAL;
+		}
 		policydb_loaded_version = policydb.policyvers;
 		ss_initialized = 1;
 		seqno = ++latest_granting;
@@ -1265,10 +1310,10 @@ int security_load_policy(void *data, size_t len)
 
 	sidtab_init(&newsidtab);
 
-	/* Verify that the existing classes did not change. */
-	if (hashtab_map(policydb.p_classes.table, validate_class, &newpolicydb)) {
-		printk(KERN_ERR "security:  the definition of an existing "
-		       "class changed\n");
+	/* Verify that the kernel defined classes are correct. */
+	if (validate_classes(&newpolicydb)) {
+		printk(KERN_ERR
+		       "security:  the definition of a class is incorrect\n");
 		rc = -EINVAL;
 		goto err;
 	}
diff --git a/security/selinux/ss/symtab.c b/security/selinux/ss/symtab.c
index 24a10d3..837658a 100644
--- a/security/selinux/ss/symtab.c
+++ b/security/selinux/ss/symtab.c
@@ -9,9 +9,9 @@
 #include <linux/errno.h>
 #include "symtab.h"
 
-static unsigned int symhash(struct hashtab *h, void *key)
+static unsigned int symhash(struct hashtab *h, const void *key)
 {
-	char *p, *keyp;
+	const char *p, *keyp;
 	unsigned int size;
 	unsigned int val;
 
@@ -23,9 +23,9 @@ static unsigned int symhash(struct hashtab *h, void *key)
 	return val & (h->size - 1);
 }
 
-static int symcmp(struct hashtab *h, void *key1, void *key2)
+static int symcmp(struct hashtab *h, const void *key1, const void *key2)
 {
-	char *keyp1, *keyp2;
+	const char *keyp1, *keyp2;
 
 	keyp1 = key1;
 	keyp2 = key2;