1 files changed, 644 insertions, 233 deletions

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index dad36a6ab45f..8f77b9a732e1 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -1,17 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Implementation of the kernel access vector cache (AVC).
  *
- * Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
+ * Authors:  Stephen Smalley, <stephen.smalley.work@gmail.com>
  *	     James Morris <jmorris@redhat.com>
  *
  * Update:   KaiGai, Kohei <kaigai@ak.jp.nec.com>
  *	Replaced the avc_lock spinlock by RCU.
  *
  * 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 version 2,
- *	as published by the Free Software Foundation.
  */
 #include <linux/types.h>
 #include <linux/stddef.h>
@@ -22,6 +19,7 @@
 #include <linux/init.h>
 #include <linux/skbuff.h>
 #include <linux/percpu.h>
+#include <linux/list.h>
 #include <net/sock.h>
 #include <linux/un.h>
 #include <net/af_unix.h>
@@ -32,10 +30,14 @@
 #include "avc.h"
 #include "avc_ss.h"
 #include "classmap.h"
+#include "hash.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/avc.h>
 
-#define AVC_CACHE_SLOTS			512
-#define AVC_DEF_CACHE_THRESHOLD		512
-#define AVC_CACHE_RECLAIM		16
+#define AVC_CACHE_SLOTS		(1 << CONFIG_SECURITY_SELINUX_AVC_HASH_BITS)
+#define AVC_DEF_CACHE_THRESHOLD	AVC_CACHE_SLOTS
+#define AVC_CACHE_RECLAIM	16
 
 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
 #define avc_cache_stats_incr(field)	this_cpu_inc(avc_cache_stats.field)
@@ -48,6 +50,7 @@ struct avc_entry {
 	u32			tsid;
 	u16			tclass;
 	struct av_decision	avd;
+	struct avc_xperms_node	*xp_node;
 };
 
 struct avc_node {
@@ -56,6 +59,16 @@ struct avc_node {
 	struct rcu_head		rhead;
 };
 
+struct avc_xperms_decision_node {
+	struct extended_perms_decision xpd;
+	struct list_head xpd_list; /* list of extended_perms_decision */
+};
+
+struct avc_xperms_node {
+	struct extended_perms xp;
+	struct list_head xpd_head; /* list head of extended_perms_decision */
+};
+
 struct avc_cache {
 	struct hlist_head	slots[AVC_CACHE_SLOTS]; /* head for avc_node->list */
 	spinlock_t		slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */
@@ -70,87 +83,49 @@ struct avc_callback_node {
 	struct avc_callback_node *next;
 };
 
-/* Exported via selinufs */
-unsigned int avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD;
-
 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
 DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 };
 #endif
 
-static struct avc_cache avc_cache;
-static struct avc_callback_node *avc_callbacks;
-static struct kmem_cache *avc_node_cachep;
+struct selinux_avc {
+	unsigned int avc_cache_threshold;
+	struct avc_cache avc_cache;
+};
 
-static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
-{
-	return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1);
-}
+static struct selinux_avc selinux_avc;
 
-/**
- * avc_dump_av - Display an access vector in human-readable form.
- * @tclass: target security class
- * @av: access vector
- */
-static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
+void selinux_avc_init(void)
 {
-	const char **perms;
-	int i, perm;
-
-	if (av == 0) {
-		audit_log_format(ab, " null");
-		return;
-	}
-
-	perms = secclass_map[tclass-1].perms;
+	int i;
 
-	audit_log_format(ab, " {");
-	i = 0;
-	perm = 1;
-	while (i < (sizeof(av) * 8)) {
-		if ((perm & av) && perms[i]) {
-			audit_log_format(ab, " %s", perms[i]);
-			av &= ~perm;
-		}
-		i++;
-		perm <<= 1;
+	selinux_avc.avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD;
+	for (i = 0; i < AVC_CACHE_SLOTS; i++) {
+		INIT_HLIST_HEAD(&selinux_avc.avc_cache.slots[i]);
+		spin_lock_init(&selinux_avc.avc_cache.slots_lock[i]);
 	}
+	atomic_set(&selinux_avc.avc_cache.active_nodes, 0);
+	atomic_set(&selinux_avc.avc_cache.lru_hint, 0);
+}
 
-	if (av)
-		audit_log_format(ab, " 0x%x", av);
-
-	audit_log_format(ab, " }");
+unsigned int avc_get_cache_threshold(void)
+{
+	return selinux_avc.avc_cache_threshold;
 }
 
-/**
- * avc_dump_query - Display a SID pair and a class in human-readable form.
- * @ssid: source security identifier
- * @tsid: target security identifier
- * @tclass: target security class
- */
-static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tclass)
+void avc_set_cache_threshold(unsigned int cache_threshold)
 {
-	int rc;
-	char *scontext;
-	u32 scontext_len;
+	selinux_avc.avc_cache_threshold = cache_threshold;
+}
 
-	rc = security_sid_to_context(ssid, &scontext, &scontext_len);
-	if (rc)
-		audit_log_format(ab, "ssid=%d", ssid);
-	else {
-		audit_log_format(ab, "scontext=%s", scontext);
-		kfree(scontext);
-	}
+static struct avc_callback_node *avc_callbacks __ro_after_init;
+static struct kmem_cache *avc_node_cachep __ro_after_init;
+static struct kmem_cache *avc_xperms_data_cachep __ro_after_init;
+static struct kmem_cache *avc_xperms_decision_cachep __ro_after_init;
+static struct kmem_cache *avc_xperms_cachep __ro_after_init;
 
-	rc = security_sid_to_context(tsid, &scontext, &scontext_len);
-	if (rc)
-		audit_log_format(ab, " tsid=%d", tsid);
-	else {
-		audit_log_format(ab, " tcontext=%s", scontext);
-		kfree(scontext);
-	}
-
-	BUG_ON(tclass >= ARRAY_SIZE(secclass_map));
-	audit_log_format(ab, " tclass=%s", secclass_map[tclass-1].name);
+static inline u32 avc_hash(u32 ssid, u32 tsid, u16 tclass)
+{
+	return av_hash(ssid, tsid, (u32)tclass, (u32)(AVC_CACHE_SLOTS - 1));
 }
 
 /**
@@ -160,19 +135,10 @@ static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tcla
  */
 void __init avc_init(void)
 {
-	int i;
-
-	for (i = 0; i < AVC_CACHE_SLOTS; i++) {
-		INIT_HLIST_HEAD(&avc_cache.slots[i]);
-		spin_lock_init(&avc_cache.slots_lock[i]);
-	}
-	atomic_set(&avc_cache.active_nodes, 0);
-	atomic_set(&avc_cache.lru_hint, 0);
-
-	avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node),
-					     0, SLAB_PANIC, NULL);
-
-	audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n");
+	avc_node_cachep = KMEM_CACHE(avc_node, SLAB_PANIC);
+	avc_xperms_cachep = KMEM_CACHE(avc_xperms_node, SLAB_PANIC);
+	avc_xperms_decision_cachep = KMEM_CACHE(avc_xperms_decision_node, SLAB_PANIC);
+	avc_xperms_data_cachep = KMEM_CACHE(extended_perms_data, SLAB_PANIC);
 }
 
 int avc_get_hash_stats(char *page)
@@ -186,7 +152,7 @@ int avc_get_hash_stats(char *page)
 	slots_used = 0;
 	max_chain_len = 0;
 	for (i = 0; i < AVC_CACHE_SLOTS; i++) {
-		head = &avc_cache.slots[i];
+		head = &selinux_avc.avc_cache.slots[i];
 		if (!hlist_empty(head)) {
 			slots_used++;
 			chain_len = 0;
@@ -201,13 +167,269 @@ int avc_get_hash_stats(char *page)
 
 	return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n"
 			 "longest chain: %d\n",
-			 atomic_read(&avc_cache.active_nodes),
+			 atomic_read(&selinux_avc.avc_cache.active_nodes),
 			 slots_used, AVC_CACHE_SLOTS, max_chain_len);
 }
 
+/*
+ * using a linked list for extended_perms_decision lookup because the list is
+ * always small. i.e. less than 5, typically 1
+ */
+static struct extended_perms_decision *
+avc_xperms_decision_lookup(u8 driver, u8 base_perm,
+			   struct avc_xperms_node *xp_node)
+{
+	struct avc_xperms_decision_node *xpd_node;
+
+	list_for_each_entry(xpd_node, &xp_node->xpd_head, xpd_list) {
+		if (xpd_node->xpd.driver == driver &&
+		    xpd_node->xpd.base_perm == base_perm)
+			return &xpd_node->xpd;
+	}
+	return NULL;
+}
+
+static inline unsigned int
+avc_xperms_has_perm(struct extended_perms_decision *xpd,
+					u8 perm, u8 which)
+{
+	unsigned int rc = 0;
+
+	if ((which == XPERMS_ALLOWED) &&
+			(xpd->used & XPERMS_ALLOWED))
+		rc = security_xperm_test(xpd->allowed->p, perm);
+	else if ((which == XPERMS_AUDITALLOW) &&
+			(xpd->used & XPERMS_AUDITALLOW))
+		rc = security_xperm_test(xpd->auditallow->p, perm);
+	else if ((which == XPERMS_DONTAUDIT) &&
+			(xpd->used & XPERMS_DONTAUDIT))
+		rc = security_xperm_test(xpd->dontaudit->p, perm);
+	return rc;
+}
+
+static void avc_xperms_allow_perm(struct avc_xperms_node *xp_node,
+				  u8 driver, u8 base_perm, u8 perm)
+{
+	struct extended_perms_decision *xpd;
+	security_xperm_set(xp_node->xp.drivers.p, driver);
+	xp_node->xp.base_perms |= base_perm;
+	xpd = avc_xperms_decision_lookup(driver, base_perm, xp_node);
+	if (xpd && xpd->allowed)
+		security_xperm_set(xpd->allowed->p, perm);
+}
+
+static void avc_xperms_decision_free(struct avc_xperms_decision_node *xpd_node)
+{
+	struct extended_perms_decision *xpd;
+
+	xpd = &xpd_node->xpd;
+	if (xpd->allowed)
+		kmem_cache_free(avc_xperms_data_cachep, xpd->allowed);
+	if (xpd->auditallow)
+		kmem_cache_free(avc_xperms_data_cachep, xpd->auditallow);
+	if (xpd->dontaudit)
+		kmem_cache_free(avc_xperms_data_cachep, xpd->dontaudit);
+	kmem_cache_free(avc_xperms_decision_cachep, xpd_node);
+}
+
+static void avc_xperms_free(struct avc_xperms_node *xp_node)
+{
+	struct avc_xperms_decision_node *xpd_node, *tmp;
+
+	if (!xp_node)
+		return;
+
+	list_for_each_entry_safe(xpd_node, tmp, &xp_node->xpd_head, xpd_list) {
+		list_del(&xpd_node->xpd_list);
+		avc_xperms_decision_free(xpd_node);
+	}
+	kmem_cache_free(avc_xperms_cachep, xp_node);
+}
+
+static void avc_copy_xperms_decision(struct extended_perms_decision *dest,
+					struct extended_perms_decision *src)
+{
+	dest->base_perm = src->base_perm;
+	dest->driver = src->driver;
+	dest->used = src->used;
+	if (dest->used & XPERMS_ALLOWED)
+		memcpy(dest->allowed->p, src->allowed->p,
+				sizeof(src->allowed->p));
+	if (dest->used & XPERMS_AUDITALLOW)
+		memcpy(dest->auditallow->p, src->auditallow->p,
+				sizeof(src->auditallow->p));
+	if (dest->used & XPERMS_DONTAUDIT)
+		memcpy(dest->dontaudit->p, src->dontaudit->p,
+				sizeof(src->dontaudit->p));
+}
+
+/*
+ * similar to avc_copy_xperms_decision, but only copy decision
+ * information relevant to this perm
+ */
+static inline void avc_quick_copy_xperms_decision(u8 perm,
+			struct extended_perms_decision *dest,
+			struct extended_perms_decision *src)
+{
+	/*
+	 * compute index of the u32 of the 256 bits (8 u32s) that contain this
+	 * command permission
+	 */
+	u8 i = perm >> 5;
+
+	dest->base_perm = src->base_perm;
+	dest->used = src->used;
+	if (dest->used & XPERMS_ALLOWED)
+		dest->allowed->p[i] = src->allowed->p[i];
+	if (dest->used & XPERMS_AUDITALLOW)
+		dest->auditallow->p[i] = src->auditallow->p[i];
+	if (dest->used & XPERMS_DONTAUDIT)
+		dest->dontaudit->p[i] = src->dontaudit->p[i];
+}
+
+static struct avc_xperms_decision_node
+		*avc_xperms_decision_alloc(u8 which)
+{
+	struct avc_xperms_decision_node *xpd_node;
+	struct extended_perms_decision *xpd;
+
+	xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, GFP_NOWAIT);
+	if (!xpd_node)
+		return NULL;
+
+	xpd = &xpd_node->xpd;
+	if (which & XPERMS_ALLOWED) {
+		xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep,
+						 GFP_NOWAIT);
+		if (!xpd->allowed)
+			goto error;
+	}
+	if (which & XPERMS_AUDITALLOW) {
+		xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep,
+						    GFP_NOWAIT);
+		if (!xpd->auditallow)
+			goto error;
+	}
+	if (which & XPERMS_DONTAUDIT) {
+		xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep,
+						   GFP_NOWAIT);
+		if (!xpd->dontaudit)
+			goto error;
+	}
+	return xpd_node;
+error:
+	avc_xperms_decision_free(xpd_node);
+	return NULL;
+}
+
+static int avc_add_xperms_decision(struct avc_node *node,
+			struct extended_perms_decision *src)
+{
+	struct avc_xperms_decision_node *dest_xpd;
+
+	dest_xpd = avc_xperms_decision_alloc(src->used);
+	if (!dest_xpd)
+		return -ENOMEM;
+	avc_copy_xperms_decision(&dest_xpd->xpd, src);
+	list_add(&dest_xpd->xpd_list, &node->ae.xp_node->xpd_head);
+	node->ae.xp_node->xp.len++;
+	return 0;
+}
+
+static struct avc_xperms_node *avc_xperms_alloc(void)
+{
+	struct avc_xperms_node *xp_node;
+
+	xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT);
+	if (!xp_node)
+		return xp_node;
+	INIT_LIST_HEAD(&xp_node->xpd_head);
+	return xp_node;
+}
+
+static int avc_xperms_populate(struct avc_node *node,
+				struct avc_xperms_node *src)
+{
+	struct avc_xperms_node *dest;
+	struct avc_xperms_decision_node *dest_xpd;
+	struct avc_xperms_decision_node *src_xpd;
+
+	if (src->xp.len == 0)
+		return 0;
+	dest = avc_xperms_alloc();
+	if (!dest)
+		return -ENOMEM;
+
+	memcpy(dest->xp.drivers.p, src->xp.drivers.p, sizeof(dest->xp.drivers.p));
+	dest->xp.len = src->xp.len;
+	dest->xp.base_perms = src->xp.base_perms;
+
+	/* for each source xpd allocate a destination xpd and copy */
+	list_for_each_entry(src_xpd, &src->xpd_head, xpd_list) {
+		dest_xpd = avc_xperms_decision_alloc(src_xpd->xpd.used);
+		if (!dest_xpd)
+			goto error;
+		avc_copy_xperms_decision(&dest_xpd->xpd, &src_xpd->xpd);
+		list_add(&dest_xpd->xpd_list, &dest->xpd_head);
+	}
+	node->ae.xp_node = dest;
+	return 0;
+error:
+	avc_xperms_free(dest);
+	return -ENOMEM;
+
+}
+
+static inline u32 avc_xperms_audit_required(u32 requested,
+					struct av_decision *avd,
+					struct extended_perms_decision *xpd,
+					u8 perm,
+					int result,
+					u32 *deniedp)
+{
+	u32 denied, audited;
+
+	denied = requested & ~avd->allowed;
+	if (unlikely(denied)) {
+		audited = denied & avd->auditdeny;
+		if (audited && xpd) {
+			if (avc_xperms_has_perm(xpd, perm, XPERMS_DONTAUDIT))
+				audited = 0;
+		}
+	} else if (result) {
+		audited = denied = requested;
+	} else {
+		audited = requested & avd->auditallow;
+		if (audited && xpd) {
+			if (!avc_xperms_has_perm(xpd, perm, XPERMS_AUDITALLOW))
+				audited = 0;
+		}
+	}
+
+	*deniedp = denied;
+	return audited;
+}
+
+static inline int avc_xperms_audit(u32 ssid, u32 tsid, u16 tclass,
+				   u32 requested, struct av_decision *avd,
+				   struct extended_perms_decision *xpd,
+				   u8 perm, int result,
+				   struct common_audit_data *ad)
+{
+	u32 audited, denied;
+
+	audited = avc_xperms_audit_required(
+			requested, avd, xpd, perm, result, &denied);
+	if (likely(!audited))
+		return 0;
+	return slow_avc_audit(ssid, tsid, tclass, requested,
+			audited, denied, result, ad);
+}
+
 static void avc_node_free(struct rcu_head *rhead)
 {
 	struct avc_node *node = container_of(rhead, struct avc_node, rhead);
+	avc_xperms_free(node->ae.xp_node);
 	kmem_cache_free(avc_node_cachep, node);
 	avc_cache_stats_incr(frees);
 }
@@ -216,21 +438,22 @@ static void avc_node_delete(struct avc_node *node)
 {
 	hlist_del_rcu(&node->list);
 	call_rcu(&node->rhead, avc_node_free);
-	atomic_dec(&avc_cache.active_nodes);
+	atomic_dec(&selinux_avc.avc_cache.active_nodes);
 }
 
 static void avc_node_kill(struct avc_node *node)
 {
+	avc_xperms_free(node->ae.xp_node);
 	kmem_cache_free(avc_node_cachep, node);
 	avc_cache_stats_incr(frees);
-	atomic_dec(&avc_cache.active_nodes);
+	atomic_dec(&selinux_avc.avc_cache.active_nodes);
 }
 
 static void avc_node_replace(struct avc_node *new, struct avc_node *old)
 {
 	hlist_replace_rcu(&old->list, &new->list);
 	call_rcu(&old->rhead, avc_node_free);
-	atomic_dec(&avc_cache.active_nodes);
+	atomic_dec(&selinux_avc.avc_cache.active_nodes);
 }
 
 static inline int avc_reclaim_node(void)
@@ -242,9 +465,10 @@ static inline int avc_reclaim_node(void)
 	spinlock_t *lock;
 
 	for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) {
-		hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1);
-		head = &avc_cache.slots[hvalue];
-		lock = &avc_cache.slots_lock[hvalue];
+		hvalue = atomic_inc_return(&selinux_avc.avc_cache.lru_hint) &
+			(AVC_CACHE_SLOTS - 1);
+		head = &selinux_avc.avc_cache.slots[hvalue];
+		lock = &selinux_avc.avc_cache.slots_lock[hvalue];
 
 		if (!spin_trylock_irqsave(lock, flags))
 			continue;
@@ -271,14 +495,15 @@ static struct avc_node *avc_alloc_node(void)
 {
 	struct avc_node *node;
 
-	node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC|__GFP_NOMEMALLOC);
+	node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT);
 	if (!node)
 		goto out;
 
 	INIT_HLIST_NODE(&node->list);
 	avc_cache_stats_incr(allocations);
 
-	if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold)
+	if (atomic_inc_return(&selinux_avc.avc_cache.active_nodes) >
+	    selinux_avc.avc_cache_threshold)
 		avc_reclaim_node();
 
 out:
@@ -296,11 +521,11 @@ static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tcl
 static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass)
 {
 	struct avc_node *node, *ret = NULL;
-	int hvalue;
+	u32 hvalue;
 	struct hlist_head *head;
 
 	hvalue = avc_hash(ssid, tsid, tclass);
-	head = &avc_cache.slots[hvalue];
+	head = &selinux_avc.avc_cache.slots[hvalue];
 	hlist_for_each_entry_rcu(node, head, list) {
 		if (ssid == node->ae.ssid &&
 		    tclass == node->ae.tclass &&
@@ -339,7 +564,7 @@ static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass)
 	return NULL;
 }
 
-static int avc_latest_notif_update(int seqno, int is_insert)
+static int avc_latest_notif_update(u32 seqno, int is_insert)
 {
 	int ret = 0;
 	static DEFINE_SPINLOCK(notif_lock);
@@ -347,14 +572,14 @@ static int avc_latest_notif_update(int seqno, int is_insert)
 
 	spin_lock_irqsave(&notif_lock, flag);
 	if (is_insert) {
-		if (seqno < avc_cache.latest_notif) {
-			printk(KERN_WARNING "SELinux: avc:  seqno %d < latest_notif %d\n",
-			       seqno, avc_cache.latest_notif);
+		if (seqno < selinux_avc.avc_cache.latest_notif) {
+			pr_warn("SELinux: avc:  seqno %d < latest_notif %d\n",
+			       seqno, selinux_avc.avc_cache.latest_notif);
 			ret = -EAGAIN;
 		}
 	} else {
-		if (seqno > avc_cache.latest_notif)
-			avc_cache.latest_notif = seqno;
+		if (seqno > selinux_avc.avc_cache.latest_notif)
+			selinux_avc.avc_cache.latest_notif = seqno;
 	}
 	spin_unlock_irqrestore(&notif_lock, flag);
 
@@ -367,6 +592,7 @@ static int avc_latest_notif_update(int seqno, int is_insert)
  * @tsid: target security identifier
  * @tclass: target security class
  * @avd: resulting av decision
+ * @xp_node: resulting extended permissions
  *
  * Insert an AVC entry for the SID pair
  * (@ssid, @tsid) and class @tclass.
@@ -375,44 +601,45 @@ static int avc_latest_notif_update(int seqno, int is_insert)
  * response to a security_compute_av() call.  If the
  * sequence number @avd->seqno is not less than the latest
  * revocation notification, then the function copies
- * the access vectors into a cache entry, returns
- * avc_node inserted. Otherwise, this function returns NULL.
+ * the access vectors into a cache entry.
  */
-static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd)
+static void avc_insert(u32 ssid, u32 tsid, u16 tclass,
+		       struct av_decision *avd, struct avc_xperms_node *xp_node)
 {
 	struct avc_node *pos, *node = NULL;
-	int hvalue;
+	u32 hvalue;
 	unsigned long flag;
+	spinlock_t *lock;
+	struct hlist_head *head;
 
 	if (avc_latest_notif_update(avd->seqno, 1))
-		goto out;
+		return;
 
 	node = avc_alloc_node();
-	if (node) {
-		struct hlist_head *head;
-		spinlock_t *lock;
-
-		hvalue = avc_hash(ssid, tsid, tclass);
-		avc_node_populate(node, ssid, tsid, tclass, avd);
+	if (!node)
+		return;
 
-		head = &avc_cache.slots[hvalue];
-		lock = &avc_cache.slots_lock[hvalue];
+	avc_node_populate(node, ssid, tsid, tclass, avd);
+	if (avc_xperms_populate(node, xp_node)) {
+		avc_node_kill(node);
+		return;
+	}
 
-		spin_lock_irqsave(lock, flag);
-		hlist_for_each_entry(pos, head, list) {
-			if (pos->ae.ssid == ssid &&
-			    pos->ae.tsid == tsid &&
-			    pos->ae.tclass == tclass) {
-				avc_node_replace(node, pos);
-				goto found;
-			}
+	hvalue = avc_hash(ssid, tsid, tclass);
+	head = &selinux_avc.avc_cache.slots[hvalue];
+	lock = &selinux_avc.avc_cache.slots_lock[hvalue];
+	spin_lock_irqsave(lock, flag);
+	hlist_for_each_entry(pos, head, list) {
+		if (pos->ae.ssid == ssid &&
+			pos->ae.tsid == tsid &&
+			pos->ae.tclass == tclass) {
+			avc_node_replace(node, pos);
+			goto found;
 		}
-		hlist_add_head_rcu(&node->list, head);
-found:
-		spin_unlock_irqrestore(lock, flag);
 	}
-out:
-	return node;
+	hlist_add_head_rcu(&node->list, head);
+found:
+	spin_unlock_irqrestore(lock, flag);
 }
 
 /**
@@ -424,11 +651,36 @@ out:
 static void avc_audit_pre_callback(struct audit_buffer *ab, void *a)
 {
 	struct common_audit_data *ad = a;
-	audit_log_format(ab, "avc:  %s ",
-			 ad->selinux_audit_data->denied ? "denied" : "granted");
-	avc_dump_av(ab, ad->selinux_audit_data->tclass,
-			ad->selinux_audit_data->audited);
-	audit_log_format(ab, " for ");
+	struct selinux_audit_data *sad = ad->selinux_audit_data;
+	u32 av = sad->audited, perm;
+	const char *const *perms;
+	u32 i;
+
+	audit_log_format(ab, "avc:  %s ", sad->denied ? "denied" : "granted");
+
+	if (av == 0) {
+		audit_log_format(ab, " null");
+		return;
+	}
+
+	perms = secclass_map[sad->tclass-1].perms;
+
+	audit_log_format(ab, " {");
+	i = 0;
+	perm = 1;
+	while (i < (sizeof(av) * 8)) {
+		if ((perm & av) && perms[i]) {
+			audit_log_format(ab, " %s", perms[i]);
+			av &= ~perm;
+		}
+		i++;
+		perm <<= 1;
+	}
+
+	if (av)
+		audit_log_format(ab, " 0x%x", av);
+
+	audit_log_format(ab, " } for ");
 }
 
 /**
@@ -440,43 +692,87 @@ static void avc_audit_pre_callback(struct audit_buffer *ab, void *a)
 static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
 {
 	struct common_audit_data *ad = a;
-	audit_log_format(ab, " ");
-	avc_dump_query(ab, ad->selinux_audit_data->ssid,
-			   ad->selinux_audit_data->tsid,
-			   ad->selinux_audit_data->tclass);
+	struct selinux_audit_data *sad = ad->selinux_audit_data;
+	char *scontext = NULL;
+	char *tcontext = NULL;
+	const char *tclass = NULL;
+	u32 scontext_len;
+	u32 tcontext_len;
+	int rc;
+
+	rc = security_sid_to_context(sad->ssid, &scontext,
+				     &scontext_len);
+	if (rc)
+		audit_log_format(ab, " ssid=%d", sad->ssid);
+	else
+		audit_log_format(ab, " scontext=%s", scontext);
+
+	rc = security_sid_to_context(sad->tsid, &tcontext,
+				     &tcontext_len);
+	if (rc)
+		audit_log_format(ab, " tsid=%d", sad->tsid);
+	else
+		audit_log_format(ab, " tcontext=%s", tcontext);
+
+	tclass = secclass_map[sad->tclass-1].name;
+	audit_log_format(ab, " tclass=%s", tclass);
+
+	if (sad->denied)
+		audit_log_format(ab, " permissive=%u", sad->result ? 0 : 1);
+
+	trace_selinux_audited(sad, scontext, tcontext, tclass);
+	kfree(tcontext);
+	kfree(scontext);
+
+	/* in case of invalid context report also the actual context string */
+	rc = security_sid_to_context_inval(sad->ssid, &scontext,
+					   &scontext_len);
+	if (!rc && scontext) {
+		if (scontext_len && scontext[scontext_len - 1] == '\0')
+			scontext_len--;
+		audit_log_format(ab, " srawcon=");
+		audit_log_n_untrustedstring(ab, scontext, scontext_len);
+		kfree(scontext);
+	}
+
+	rc = security_sid_to_context_inval(sad->tsid, &scontext,
+					   &scontext_len);
+	if (!rc && scontext) {
+		if (scontext_len && scontext[scontext_len - 1] == '\0')
+			scontext_len--;
+		audit_log_format(ab, " trawcon=");
+		audit_log_n_untrustedstring(ab, scontext, scontext_len);
+		kfree(scontext);
+	}
 }
 
-/* This is the slow part of avc audit with big stack footprint */
+/*
+ * This is the slow part of avc audit with big stack footprint.
+ * Note that it is non-blocking and can be called from under
+ * rcu_read_lock().
+ */
 noinline int slow_avc_audit(u32 ssid, u32 tsid, u16 tclass,
-		u32 requested, u32 audited, u32 denied,
-		struct common_audit_data *a,
-		unsigned flags)
+			    u32 requested, u32 audited, u32 denied, int result,
+			    struct common_audit_data *a)
 {
 	struct common_audit_data stack_data;
 	struct selinux_audit_data sad;
 
+	if (WARN_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map)))
+		return -EINVAL;
+
 	if (!a) {
 		a = &stack_data;
 		a->type = LSM_AUDIT_DATA_NONE;
 	}
 
-	/*
-	 * When in a RCU walk do the audit on the RCU retry.  This is because
-	 * the collection of the dname in an inode audit message is not RCU
-	 * safe.  Note this may drop some audits when the situation changes
-	 * during retry. However this is logically just as if the operation
-	 * happened a little later.
-	 */
-	if ((a->type == LSM_AUDIT_DATA_INODE) &&
-	    (flags & MAY_NOT_BLOCK))
-		return -ECHILD;
-
 	sad.tclass = tclass;
 	sad.requested = requested;
 	sad.ssid = ssid;
 	sad.tsid = tsid;
 	sad.audited = audited;
 	sad.denied = denied;
+	sad.result = result;
 
 	a->selinux_audit_data = &sad;
 
@@ -512,27 +808,31 @@ out:
 	return rc;
 }
 
-static inline int avc_sidcmp(u32 x, u32 y)
-{
-	return (x == y || x == SECSID_WILD || y == SECSID_WILD);
-}
-
 /**
- * avc_update_node Update an AVC entry
+ * avc_update_node - Update an AVC entry
  * @event : Updating event
  * @perms : Permission mask bits
- * @ssid,@tsid,@tclass : identifier of an AVC entry
+ * @driver: xperm driver information
+ * @base_perm: the base permission associated with the extended permission
+ * @xperm: xperm permissions
+ * @ssid: AVC entry source sid
+ * @tsid: AVC entry target sid
+ * @tclass : AVC entry target object class
  * @seqno : sequence number when decision was made
+ * @xpd: extended_perms_decision to be added to the node
+ * @flags: the AVC_* flags, e.g. AVC_EXTENDED_PERMS, or 0.
  *
  * if a valid AVC entry doesn't exist,this function returns -ENOENT.
  * if kmalloc() called internal returns NULL, this function returns -ENOMEM.
  * otherwise, this function updates the AVC entry. The original AVC-entry object
  * will release later by RCU.
  */
-static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass,
-			   u32 seqno)
+static int avc_update_node(u32 event, u32 perms, u8 driver, u8 base_perm,
+			   u8 xperm, u32 ssid, u32 tsid, u16 tclass, u32 seqno,
+			   struct extended_perms_decision *xpd, u32 flags)
 {
-	int hvalue, rc = 0;
+	u32 hvalue;
+	int rc = 0;
 	unsigned long flag;
 	struct avc_node *pos, *node, *orig = NULL;
 	struct hlist_head *head;
@@ -547,8 +847,8 @@ static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass,
 	/* Lock the target slot */
 	hvalue = avc_hash(ssid, tsid, tclass);
 
-	head = &avc_cache.slots[hvalue];
-	lock = &avc_cache.slots_lock[hvalue];
+	head = &selinux_avc.avc_cache.slots[hvalue];
+	lock = &selinux_avc.avc_cache.slots_lock[hvalue];
 
 	spin_lock_irqsave(lock, flag);
 
@@ -574,9 +874,19 @@ static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass,
 
 	avc_node_populate(node, ssid, tsid, tclass, &orig->ae.avd);
 
+	if (orig->ae.xp_node) {
+		rc = avc_xperms_populate(node, orig->ae.xp_node);
+		if (rc) {
+			avc_node_kill(node);
+			goto out_unlock;
+		}
+	}
+
 	switch (event) {
 	case AVC_CALLBACK_GRANT:
 		node->ae.avd.allowed |= perms;
+		if (node->ae.xp_node && (flags & AVC_EXTENDED_PERMS))
+			avc_xperms_allow_perm(node->ae.xp_node, driver, base_perm, xperm);
 		break;
 	case AVC_CALLBACK_TRY_REVOKE:
 	case AVC_CALLBACK_REVOKE:
@@ -594,6 +904,13 @@ static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass,
 	case AVC_CALLBACK_AUDITDENY_DISABLE:
 		node->ae.avd.auditdeny &= ~perms;
 		break;
+	case AVC_CALLBACK_ADD_XPERMS:
+		rc = avc_add_xperms_decision(node, xpd);
+		if (rc) {
+			avc_node_kill(node);
+			goto out_unlock;
+		}
+		break;
 	}
 	avc_node_replace(node, orig);
 out_unlock:
@@ -614,12 +931,12 @@ static void avc_flush(void)
 	int i;
 
 	for (i = 0; i < AVC_CACHE_SLOTS; i++) {
-		head = &avc_cache.slots[i];
-		lock = &avc_cache.slots_lock[i];
+		head = &selinux_avc.avc_cache.slots[i];
+		lock = &selinux_avc.avc_cache.slots_lock[i];
 
 		spin_lock_irqsave(lock, flag);
 		/*
-		 * With preemptable RCU, the outer spinlock does not
+		 * With preemptible RCU, the outer spinlock does not
 		 * prevent RCU grace periods from ending.
 		 */
 		rcu_read_lock();
@@ -655,40 +972,155 @@ int avc_ss_reset(u32 seqno)
 	return rc;
 }
 
-/*
- * Slow-path helper function for avc_has_perm_noaudit,
- * when the avc_node lookup fails. We get called with
- * the RCU read lock held, and need to return with it
- * still held, but drop if for the security compute.
+/**
+ * avc_compute_av - Add an entry to the AVC based on the security policy
+ * @ssid: subject
+ * @tsid: object/target
+ * @tclass: object class
+ * @avd: access vector decision
+ * @xp_node: AVC extended permissions node
  *
- * Don't inline this, since it's the slow-path and just
- * results in a bigger stack frame.
+ * Slow-path helper function for avc_has_perm_noaudit, when the avc_node lookup
+ * fails.  Don't inline this, since it's the slow-path and just results in a
+ * bigger stack frame.
  */
-static noinline struct avc_node *avc_compute_av(u32 ssid, u32 tsid,
-			 u16 tclass, struct av_decision *avd)
+static noinline void avc_compute_av(u32 ssid, u32 tsid, u16 tclass,
+				    struct av_decision *avd,
+				    struct avc_xperms_node *xp_node)
 {
-	rcu_read_unlock();
-	security_compute_av(ssid, tsid, tclass, avd);
-	rcu_read_lock();
-	return avc_insert(ssid, tsid, tclass, avd);
+	INIT_LIST_HEAD(&xp_node->xpd_head);
+	security_compute_av(ssid, tsid, tclass, avd, &xp_node->xp);
+	avc_insert(ssid, tsid, tclass, avd, xp_node);
 }
 
-static noinline int avc_denied(u32 ssid, u32 tsid,
-			 u16 tclass, u32 requested,
-			 unsigned flags,
-			 struct av_decision *avd)
+static noinline int avc_denied(u32 ssid, u32 tsid, u16 tclass, u32 requested,
+			       u8 driver, u8 base_perm, u8 xperm,
+			       unsigned int flags, struct av_decision *avd)
 {
 	if (flags & AVC_STRICT)
 		return -EACCES;
 
-	if (selinux_enforcing && !(avd->flags & AVD_FLAGS_PERMISSIVE))
+	if (enforcing_enabled() &&
+	    !(avd->flags & AVD_FLAGS_PERMISSIVE))
 		return -EACCES;
 
-	avc_update_node(AVC_CALLBACK_GRANT, requested, ssid,
-				tsid, tclass, avd->seqno);
+	avc_update_node(AVC_CALLBACK_GRANT, requested, driver, base_perm,
+			xperm, ssid, tsid, tclass, avd->seqno, NULL, flags);
 	return 0;
 }
 
+/*
+ * The avc extended permissions logic adds an additional 256 bits of
+ * permissions to an avc node when extended permissions for that node are
+ * specified in the avtab. If the additional 256 permissions is not adequate,
+ * as-is the case with ioctls, then multiple may be chained together and the
+ * driver field is used to specify which set contains the permission.
+ */
+int avc_has_extended_perms(u32 ssid, u32 tsid, u16 tclass, u32 requested,
+			   u8 driver, u8 base_perm, u8 xperm,
+			   struct common_audit_data *ad)
+{
+	struct avc_node *node;
+	struct av_decision avd;
+	u32 denied;
+	struct extended_perms_decision local_xpd;
+	struct extended_perms_decision *xpd = NULL;
+	struct extended_perms_data allowed;
+	struct extended_perms_data auditallow;
+	struct extended_perms_data dontaudit;
+	struct avc_xperms_node local_xp_node;
+	struct avc_xperms_node *xp_node;
+	int rc = 0, rc2;
+
+	xp_node = &local_xp_node;
+	if (WARN_ON(!requested))
+		return -EACCES;
+
+	rcu_read_lock();
+
+	node = avc_lookup(ssid, tsid, tclass);
+	if (unlikely(!node)) {
+		avc_compute_av(ssid, tsid, tclass, &avd, xp_node);
+	} else {
+		memcpy(&avd, &node->ae.avd, sizeof(avd));
+		xp_node = node->ae.xp_node;
+	}
+	/* if extended permissions are not defined, only consider av_decision */
+	if (!xp_node || !xp_node->xp.len)
+		goto decision;
+
+	local_xpd.allowed = &allowed;
+	local_xpd.auditallow = &auditallow;
+	local_xpd.dontaudit = &dontaudit;
+
+	xpd = avc_xperms_decision_lookup(driver, base_perm, xp_node);
+	if (unlikely(!xpd)) {
+		/*
+		 * Compute the extended_perms_decision only if the driver
+		 * is flagged and the base permission is known.
+		 */
+		if (!security_xperm_test(xp_node->xp.drivers.p, driver) ||
+		    !(xp_node->xp.base_perms & base_perm)) {
+			avd.allowed &= ~requested;
+			goto decision;
+		}
+		rcu_read_unlock();
+		security_compute_xperms_decision(ssid, tsid, tclass, driver,
+						 base_perm, &local_xpd);
+		rcu_read_lock();
+		avc_update_node(AVC_CALLBACK_ADD_XPERMS, requested, driver,
+				base_perm, xperm, ssid, tsid, tclass, avd.seqno,
+				&local_xpd, 0);
+	} else {
+		avc_quick_copy_xperms_decision(xperm, &local_xpd, xpd);
+	}
+	xpd = &local_xpd;
+
+	if (!avc_xperms_has_perm(xpd, xperm, XPERMS_ALLOWED))
+		avd.allowed &= ~requested;
+
+decision:
+	denied = requested & ~(avd.allowed);
+	if (unlikely(denied))
+		rc = avc_denied(ssid, tsid, tclass, requested, driver,
+				base_perm, xperm, AVC_EXTENDED_PERMS, &avd);
+
+	rcu_read_unlock();
+
+	rc2 = avc_xperms_audit(ssid, tsid, tclass, requested,
+			&avd, xpd, xperm, rc, ad);
+	if (rc2)
+		return rc2;
+	return rc;
+}
+
+/**
+ * avc_perm_nonode - Add an entry to the AVC
+ * @ssid: subject
+ * @tsid: object/target
+ * @tclass: object class
+ * @requested: requested permissions
+ * @flags: AVC flags
+ * @avd: access vector decision
+ *
+ * This is the "we have no node" part of avc_has_perm_noaudit(), which is
+ * unlikely and needs extra stack space for the new node that we generate, so
+ * don't inline it.
+ */
+static noinline int avc_perm_nonode(u32 ssid, u32 tsid, u16 tclass,
+				    u32 requested, unsigned int flags,
+				    struct av_decision *avd)
+{
+	u32 denied;
+	struct avc_xperms_node xp_node;
+
+	avc_compute_av(ssid, tsid, tclass, avd, &xp_node);
+	denied = requested & ~(avd->allowed);
+	if (unlikely(denied))
+		return avc_denied(ssid, tsid, tclass, requested, 0, 0, 0,
+				  flags, avd);
+	return 0;
+}
 
 /**
  * avc_has_perm_noaudit - Check permissions but perform no auditing.
@@ -711,32 +1143,31 @@ static noinline int avc_denied(u32 ssid, u32 tsid,
  * should be released for the auditing.
  */
 inline int avc_has_perm_noaudit(u32 ssid, u32 tsid,
-			 u16 tclass, u32 requested,
-			 unsigned flags,
-			 struct av_decision *avd)
+				u16 tclass, u32 requested,
+				unsigned int flags,
+				struct av_decision *avd)
 {
-	struct avc_node *node;
-	int rc = 0;
 	u32 denied;
+	struct avc_node *node;
 
-	BUG_ON(!requested);
+	if (WARN_ON(!requested))
+		return -EACCES;
 
 	rcu_read_lock();
-
 	node = avc_lookup(ssid, tsid, tclass);
 	if (unlikely(!node)) {
-		node = avc_compute_av(ssid, tsid, tclass, avd);
-	} else {
-		memcpy(avd, &node->ae.avd, sizeof(*avd));
-		avd = &node->ae.avd;
+		rcu_read_unlock();
+		return avc_perm_nonode(ssid, tsid, tclass, requested,
+				       flags, avd);
 	}
+	denied = requested & ~node->ae.avd.allowed;
+	memcpy(avd, &node->ae.avd, sizeof(*avd));
+	rcu_read_unlock();
 
-	denied = requested & ~(avd->allowed);
 	if (unlikely(denied))
-		rc = avc_denied(ssid, tsid, tclass, requested, flags, avd);
-
-	rcu_read_unlock();
-	return rc;
+		return avc_denied(ssid, tsid, tclass, requested, 0, 0, 0,
+				  flags, avd);
+	return 0;
 }
 
 /**
@@ -746,7 +1177,6 @@ inline int avc_has_perm_noaudit(u32 ssid, u32 tsid,
  * @tclass: target security class
  * @requested: requested permissions, interpreted based on @tclass
  * @auditdata: auxiliary audit data
- * @flags: VFS walk flags
  *
  * Check the AVC to determine whether the @requested permissions are granted
  * for the SID pair (@ssid, @tsid), interpreting the permissions
@@ -756,17 +1186,17 @@ inline int avc_has_perm_noaudit(u32 ssid, u32 tsid,
  * permissions are granted, -%EACCES if any permissions are denied, or
  * another -errno upon other errors.
  */
-int avc_has_perm_flags(u32 ssid, u32 tsid, u16 tclass,
-		       u32 requested, struct common_audit_data *auditdata,
-		       unsigned flags)
+int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
+		 u32 requested, struct common_audit_data *auditdata)
 {
 	struct av_decision avd;
 	int rc, rc2;
 
-	rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
+	rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0,
+				  &avd);
 
-	rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata,
-			flags);
+	rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc,
+			auditdata);
 	if (rc2)
 		return rc2;
 	return rc;
@@ -774,24 +1204,5 @@ int avc_has_perm_flags(u32 ssid, u32 tsid, u16 tclass,
 
 u32 avc_policy_seqno(void)
 {
-	return avc_cache.latest_notif;
-}
-
-void avc_disable(void)
-{
-	/*
-	 * If you are looking at this because you have realized that we are
-	 * not destroying the avc_node_cachep it might be easy to fix, but
-	 * I don't know the memory barrier semantics well enough to know.  It's
-	 * possible that some other task dereferenced security_ops when
-	 * it still pointed to selinux operations.  If that is the case it's
-	 * possible that it is about to use the avc and is about to need the
-	 * avc_node_cachep.  I know I could wrap the security.c security_ops call
-	 * in an rcu_lock, but seriously, it's not worth it.  Instead I just flush
-	 * the cache and get that memory back.
-	 */
-	if (avc_node_cachep) {
-		avc_flush();
-		/* kmem_cache_destroy(avc_node_cachep); */
-	}
+	return selinux_avc.avc_cache.latest_notif;
 }