* Implementation of the kernel access vector cache (AVC).
*
* Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
- * James Morris <jmorris@redhat.com>
+ * James Morris <jmorris@redhat.com>
*
* Update: KaiGai, Kohei <kaigai@ak.jp.nec.com>
- * Replaced the avc_lock spinlock by RCU.
+ * 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.
+ * as published by the Free Software Foundation.
*/
#include <linux/types.h>
#include <linux/stddef.h>
#undef S_
};
-#define TB_(s) static const char * s [] = {
+#define TB_(s) static const char *s[] = {
#define TE_(s) };
#define S_(s) s,
#include "common_perm_to_string.h"
#undef S_
static const struct av_inherit av_inherit[] = {
-#define S_(c, i, b) { c, common_##i##_perm_to_string, b },
+#define S_(c, i, b) { .tclass = c,\
+ .common_pts = common_##i##_perm_to_string,\
+ .common_base = 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)
+ .av_perm_to_string = av_perm_to_string,
+ .av_pts_len = ARRAY_SIZE(av_perm_to_string),
+ .class_to_string = class_to_string,
+ .cts_len = ARRAY_SIZE(class_to_string),
+ .av_inherit = av_inherit,
+ .av_inherit_len = ARRAY_SIZE(av_inherit)
};
#define AVC_CACHE_SLOTS 512
#define AVC_CACHE_RECLAIM 16
#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
-#define avc_cache_stats_incr(field) \
+#define avc_cache_stats_incr(field) \
do { \
per_cpu(avc_cache_stats, get_cpu()).field++; \
put_cpu(); \
u32 tsid;
u16 tclass;
struct av_decision avd;
- atomic_t used; /* used recently */
};
struct avc_node {
struct avc_entry ae;
- struct list_head list;
- struct rcu_head rhead;
+ struct hlist_node list; /* anchored in avc_cache->slots[i] */
+ struct rcu_head rhead;
};
struct avc_cache {
- struct list_head slots[AVC_CACHE_SLOTS];
+ struct hlist_head slots[AVC_CACHE_SLOTS]; /* head for avc_node->list */
spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */
atomic_t lru_hint; /* LRU hint for reclaim scan */
atomic_t active_nodes;
struct avc_callback_node {
int (*callback) (u32 event, u32 ssid, u32 tsid,
- u16 tclass, u32 perms,
- u32 *out_retained);
+ u16 tclass, u32 perms,
+ u32 *out_retained);
u32 events;
u32 ssid;
u32 tsid;
static struct avc_cache avc_cache;
static struct avc_callback_node *avc_callbacks;
-static kmem_cache_t *avc_node_cachep;
+static struct kmem_cache *avc_node_cachep;
static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
{
* @tclass: target security class
* @av: access vector
*/
-static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
+void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
{
const char **common_pts = NULL;
u32 common_base = 0;
char *scontext;
u32 scontext_len;
- rc = security_sid_to_context(ssid, &scontext, &scontext_len);
+ rc = security_sid_to_context(ssid, &scontext, &scontext_len);
if (rc)
audit_log_format(ab, "ssid=%d", ssid);
else {
audit_log_format(ab, " tcontext=%s", scontext);
kfree(scontext);
}
+
+ BUG_ON(tclass >= ARRAY_SIZE(class_to_string) || !class_to_string[tclass]);
audit_log_format(ab, " tclass=%s", class_to_string[tclass]);
}
int i;
for (i = 0; i < AVC_CACHE_SLOTS; i++) {
- INIT_LIST_HEAD(&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, NULL);
+ 0, SLAB_PANIC, NULL);
audit_log(current->audit_context, GFP_KERNEL, AUDIT_KERNEL, "AVC INITIALIZED\n");
}
{
int i, chain_len, max_chain_len, slots_used;
struct avc_node *node;
+ struct hlist_head *head;
rcu_read_lock();
slots_used = 0;
max_chain_len = 0;
for (i = 0; i < AVC_CACHE_SLOTS; i++) {
- if (!list_empty(&avc_cache.slots[i])) {
+ head = &avc_cache.slots[i];
+ if (!hlist_empty(head)) {
+ struct hlist_node *next;
+
slots_used++;
chain_len = 0;
- list_for_each_entry_rcu(node, &avc_cache.slots[i], list)
+ hlist_for_each_entry_rcu(node, next, head, list)
chain_len++;
if (chain_len > max_chain_len)
max_chain_len = chain_len;
static void avc_node_delete(struct avc_node *node)
{
- list_del_rcu(&node->list);
+ hlist_del_rcu(&node->list);
call_rcu(&node->rhead, avc_node_free);
atomic_dec(&avc_cache.active_nodes);
}
static void avc_node_replace(struct avc_node *new, struct avc_node *old)
{
- list_replace_rcu(&old->list, &new->list);
+ hlist_replace_rcu(&old->list, &new->list);
call_rcu(&old->rhead, avc_node_free);
atomic_dec(&avc_cache.active_nodes);
}
struct avc_node *node;
int hvalue, try, ecx;
unsigned long flags;
+ struct hlist_head *head;
+ struct hlist_node *next;
+ spinlock_t *lock;
- for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++ ) {
+ 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];
- if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags))
+ if (!spin_trylock_irqsave(lock, flags))
continue;
- list_for_each_entry(node, &avc_cache.slots[hvalue], list) {
- if (atomic_dec_and_test(&node->ae.used)) {
- /* Recently Unused */
- avc_node_delete(node);
- avc_cache_stats_incr(reclaims);
- ecx++;
- if (ecx >= AVC_CACHE_RECLAIM) {
- spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
- goto out;
- }
+ rcu_read_lock();
+ hlist_for_each_entry(node, next, head, list) {
+ avc_node_delete(node);
+ avc_cache_stats_incr(reclaims);
+ ecx++;
+ if (ecx >= AVC_CACHE_RECLAIM) {
+ rcu_read_unlock();
+ spin_unlock_irqrestore(lock, flags);
+ goto out;
}
}
- spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
+ rcu_read_unlock();
+ spin_unlock_irqrestore(lock, flags);
}
out:
return ecx;
{
struct avc_node *node;
- node = kmem_cache_alloc(avc_node_cachep, SLAB_ATOMIC);
+ node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC);
if (!node)
goto out;
- memset(node, 0, sizeof(*node));
INIT_RCU_HEAD(&node->rhead);
- INIT_LIST_HEAD(&node->list);
- atomic_set(&node->ae.used, 1);
+ INIT_HLIST_NODE(&node->list);
avc_cache_stats_incr(allocations);
if (atomic_inc_return(&avc_cache.active_nodes) > avc_cache_threshold)
return node;
}
-static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae)
+static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd)
{
node->ae.ssid = ssid;
node->ae.tsid = tsid;
node->ae.tclass = tclass;
- memcpy(&node->ae.avd, &ae->avd, sizeof(node->ae.avd));
+ memcpy(&node->ae.avd, avd, sizeof(node->ae.avd));
}
static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass)
{
struct avc_node *node, *ret = NULL;
int hvalue;
+ struct hlist_head *head;
+ struct hlist_node *next;
hvalue = avc_hash(ssid, tsid, tclass);
- list_for_each_entry_rcu(node, &avc_cache.slots[hvalue], list) {
+ head = &avc_cache.slots[hvalue];
+ hlist_for_each_entry_rcu(node, next, head, list) {
if (ssid == node->ae.ssid &&
tclass == node->ae.tclass &&
tsid == node->ae.tsid) {
}
}
- if (ret == NULL) {
- /* cache miss */
- goto out;
- }
-
- /* cache hit */
- if (atomic_read(&ret->ae.used) != 1)
- atomic_set(&ret->ae.used, 1);
-out:
return ret;
}
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
- * @requested: requested permissions, interpreted based on @tclass
*
* Look up an AVC entry that is valid for the
- * @requested permissions between the SID pair
* (@ssid, @tsid), interpreting the permissions
* based on @tclass. If a valid AVC entry exists,
* then this function return the avc_node.
* Otherwise, this function returns NULL.
*/
-static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass, u32 requested)
+static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass)
{
struct avc_node *node;
avc_cache_stats_incr(lookups);
node = avc_search_node(ssid, tsid, tclass);
- if (node && ((node->ae.avd.decided & requested) == requested)) {
+ if (node)
avc_cache_stats_incr(hits);
- goto out;
- }
+ else
+ avc_cache_stats_incr(misses);
- node = NULL;
- avc_cache_stats_incr(misses);
-out:
return node;
}
spin_lock_irqsave(¬if_lock, flag);
if (is_insert) {
if (seqno < avc_cache.latest_notif) {
- printk(KERN_WARNING "avc: seqno %d < latest_notif %d\n",
+ printk(KERN_WARNING "SELinux: avc: seqno %d < latest_notif %d\n",
seqno, avc_cache.latest_notif);
ret = -EAGAIN;
}
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
- * @ae: AVC entry
+ * @avd: resulting av decision
*
* Insert an AVC entry for the SID pair
* (@ssid, @tsid) and class @tclass.
* The access vectors and the sequence number are
* normally provided by the security server in
* response to a security_compute_av() call. If the
- * sequence number @ae->avd.seqno is not less than the latest
+ * 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.
*/
-static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_entry *ae)
+static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd)
{
struct avc_node *pos, *node = NULL;
int hvalue;
unsigned long flag;
- if (avc_latest_notif_update(ae->avd.seqno, 1))
+ if (avc_latest_notif_update(avd->seqno, 1))
goto out;
node = avc_alloc_node();
if (node) {
+ struct hlist_head *head;
+ struct hlist_node *next;
+ spinlock_t *lock;
+
hvalue = avc_hash(ssid, tsid, tclass);
- avc_node_populate(node, ssid, tsid, tclass, ae);
+ avc_node_populate(node, ssid, tsid, tclass, avd);
- spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag);
- list_for_each_entry(pos, &avc_cache.slots[hvalue], list) {
+ head = &avc_cache.slots[hvalue];
+ lock = &avc_cache.slots_lock[hvalue];
+
+ spin_lock_irqsave(lock, flag);
+ hlist_for_each_entry(pos, next, head, list) {
if (pos->ae.ssid == ssid &&
pos->ae.tsid == tsid &&
pos->ae.tclass == tclass) {
- avc_node_replace(node, pos);
+ avc_node_replace(node, pos);
goto found;
}
}
- list_add_rcu(&node->list, &avc_cache.slots[hvalue]);
+ hlist_add_head_rcu(&node->list, head);
found:
- spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag);
+ spin_unlock_irqrestore(lock, flag);
}
out:
return node;
char *name1, char *name2)
{
if (!ipv6_addr_any(addr))
- audit_log_format(ab, " %s=" NIP6_FMT, name1, NIP6(*addr));
+ audit_log_format(ab, " %s=%pI6", name1, addr);
if (port)
audit_log_format(ab, " %s=%d", name2, ntohs(port));
}
__be16 port, char *name1, char *name2)
{
if (addr)
- audit_log_format(ab, " %s=" NIPQUAD_FMT, name1, NIPQUAD(addr));
+ audit_log_format(ab, " %s=%pI4", name1, &addr);
if (port)
audit_log_format(ab, " %s=%d", name2, ntohs(port));
}
* before calling the auditing code.
*/
void avc_audit(u32 ssid, u32 tsid,
- u16 tclass, u32 requested,
- struct av_decision *avd, int result, struct avc_audit_data *a)
+ u16 tclass, u32 requested,
+ struct av_decision *avd, int result, struct avc_audit_data *a)
{
struct task_struct *tsk = current;
struct inode *inode = NULL;
return;
} else if (result) {
audited = denied = requested;
- } else {
+ } else {
audited = requested;
if (!(audited & avd->auditallow))
return;
if (!ab)
return; /* audit_panic has been called */
audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted");
- avc_dump_av(ab, tclass,audited);
+ avc_dump_av(ab, tclass, audited);
audit_log_format(ab, " for ");
if (a && a->tsk)
tsk = a->tsk;
audit_log_format(ab, " capability=%d", a->u.cap);
break;
case AVC_AUDIT_DATA_FS:
- if (a->u.fs.dentry) {
- struct dentry *dentry = a->u.fs.dentry;
- if (a->u.fs.mnt)
- audit_avc_path(dentry, a->u.fs.mnt);
- audit_log_format(ab, " name=");
- audit_log_untrustedstring(ab, dentry->d_name.name);
+ if (a->u.fs.path.dentry) {
+ struct dentry *dentry = a->u.fs.path.dentry;
+ if (a->u.fs.path.mnt) {
+ audit_log_d_path(ab, "path=",
+ &a->u.fs.path);
+ } else {
+ audit_log_format(ab, " name=");
+ audit_log_untrustedstring(ab, dentry->d_name.name);
+ }
inode = dentry->d_inode;
} else if (a->u.fs.inode) {
struct dentry *dentry;
}
}
if (inode)
- audit_log_format(ab, " dev=%s ino=%ld",
+ audit_log_format(ab, " dev=%s ino=%lu",
inode->i_sb->s_id,
inode->i_ino);
break;
case AF_UNIX:
u = unix_sk(sk);
if (u->dentry) {
- audit_avc_path(u->dentry, u->mnt);
- audit_log_format(ab, " name=");
- audit_log_untrustedstring(ab, u->dentry->d_name.name);
+ struct path path = {
+ .dentry = u->dentry,
+ .mnt = u->mnt
+ };
+ audit_log_d_path(ab, "path=",
+ &path);
break;
}
if (!u->addr)
if (*p)
audit_log_untrustedstring(ab, p);
else
- audit_log_hex(ab, p, len);
+ audit_log_n_hex(ab, p, len);
break;
}
}
-
+
switch (a->u.net.family) {
case AF_INET:
avc_print_ipv4_addr(ab, a->u.net.v4info.saddr,
"daddr", "dest");
break;
}
- if (a->u.net.netif)
- audit_log_format(ab, " netif=%s",
- a->u.net.netif);
+ if (a->u.net.netif > 0) {
+ struct net_device *dev;
+
+ /* NOTE: we always use init's namespace */
+ dev = dev_get_by_index(&init_net,
+ a->u.net.netif);
+ if (dev) {
+ audit_log_format(ab, " netif=%s",
+ dev->name);
+ dev_put(dev);
+ }
+ }
break;
}
}
* -%ENOMEM if insufficient memory exists to add the callback.
*/
int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
- u16 tclass, u32 perms,
- u32 *out_retained),
- u32 events, u32 ssid, u32 tsid,
- u16 tclass, u32 perms)
+ u16 tclass, u32 perms,
+ u32 *out_retained),
+ u32 events, u32 ssid, u32 tsid,
+ u16 tclass, u32 perms)
{
struct avc_callback_node *c;
int rc = 0;
* @event : Updating event
* @perms : Permission mask bits
* @ssid,@tsid,@tclass : identifier of an AVC entry
+ * @seqno : sequence number when decision was made
*
* 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 update 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)
+static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass,
+ u32 seqno)
{
int hvalue, rc = 0;
unsigned long flag;
struct avc_node *pos, *node, *orig = NULL;
+ struct hlist_head *head;
+ struct hlist_node *next;
+ spinlock_t *lock;
node = avc_alloc_node();
if (!node) {
/* Lock the target slot */
hvalue = avc_hash(ssid, tsid, tclass);
- spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag);
- list_for_each_entry(pos, &avc_cache.slots[hvalue], list){
- if ( ssid==pos->ae.ssid &&
- tsid==pos->ae.tsid &&
- tclass==pos->ae.tclass ){
+ head = &avc_cache.slots[hvalue];
+ lock = &avc_cache.slots_lock[hvalue];
+
+ spin_lock_irqsave(lock, flag);
+
+ hlist_for_each_entry(pos, next, head, list) {
+ if (ssid == pos->ae.ssid &&
+ tsid == pos->ae.tsid &&
+ tclass == pos->ae.tclass &&
+ seqno == pos->ae.avd.seqno){
orig = pos;
break;
}
* Copy and replace original node.
*/
- avc_node_populate(node, ssid, tsid, tclass, &orig->ae);
+ avc_node_populate(node, ssid, tsid, tclass, &orig->ae.avd);
switch (event) {
case AVC_CALLBACK_GRANT:
}
avc_node_replace(node, orig);
out_unlock:
- spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flag);
+ spin_unlock_irqrestore(lock, flag);
out:
return rc;
}
int i, rc = 0, tmprc;
unsigned long flag;
struct avc_node *node;
+ struct hlist_head *head;
+ struct hlist_node *next;
+ spinlock_t *lock;
for (i = 0; i < AVC_CACHE_SLOTS; i++) {
- spin_lock_irqsave(&avc_cache.slots_lock[i], flag);
- list_for_each_entry(node, &avc_cache.slots[i], list)
+ head = &avc_cache.slots[i];
+ lock = &avc_cache.slots_lock[i];
+
+ spin_lock_irqsave(lock, flag);
+ /*
+ * With preemptable RCU, the outer spinlock does not
+ * prevent RCU grace periods from ending.
+ */
+ rcu_read_lock();
+ hlist_for_each_entry(node, next, head, list)
avc_node_delete(node);
- spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag);
+ rcu_read_unlock();
+ spin_unlock_irqrestore(lock, flag);
}
for (c = avc_callbacks; c; c = c->next) {
if (c->events & AVC_CALLBACK_RESET) {
tmprc = c->callback(AVC_CALLBACK_RESET,
- 0, 0, 0, 0, NULL);
+ 0, 0, 0, 0, NULL);
/* save the first error encountered for the return
value and continue processing the callbacks */
if (!rc)
* @tsid: target security identifier
* @tclass: target security class
* @requested: requested permissions, interpreted based on @tclass
+ * @flags: AVC_STRICT or 0
* @avd: access vector decisions
*
* Check the AVC to determine whether the @requested permissions are granted
* should be released for the auditing.
*/
int avc_has_perm_noaudit(u32 ssid, u32 tsid,
- u16 tclass, u32 requested,
- struct av_decision *avd)
+ u16 tclass, u32 requested,
+ unsigned flags,
+ struct av_decision *in_avd)
{
struct avc_node *node;
- struct avc_entry entry, *p_ae;
+ struct av_decision avd_entry, *avd;
int rc = 0;
u32 denied;
+ BUG_ON(!requested);
+
rcu_read_lock();
- node = avc_lookup(ssid, tsid, tclass, requested);
+ node = avc_lookup(ssid, tsid, tclass);
if (!node) {
rcu_read_unlock();
- rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd);
+
+ if (in_avd)
+ avd = in_avd;
+ else
+ avd = &avd_entry;
+
+ rc = security_compute_av(ssid, tsid, tclass, requested, avd);
if (rc)
goto out;
rcu_read_lock();
- node = avc_insert(ssid,tsid,tclass,&entry);
+ node = avc_insert(ssid, tsid, tclass, avd);
+ } else {
+ if (in_avd)
+ memcpy(in_avd, &node->ae.avd, sizeof(*in_avd));
+ avd = &node->ae.avd;
}
- p_ae = node ? &node->ae : &entry;
-
- if (avd)
- memcpy(avd, &p_ae->avd, sizeof(*avd));
+ denied = requested & ~(avd->allowed);
- denied = requested & ~(p_ae->avd.allowed);
-
- if (!requested || denied) {
- if (selinux_enforcing)
+ if (denied) {
+ if (flags & AVC_STRICT)
rc = -EACCES;
+ else if (!selinux_enforcing || security_permissive_sid(ssid))
+ avc_update_node(AVC_CALLBACK_GRANT, requested, ssid,
+ tsid, tclass, avd->seqno);
else
- if (node)
- avc_update_node(AVC_CALLBACK_GRANT,requested,
- ssid,tsid,tclass);
+ rc = -EACCES;
}
rcu_read_unlock();
* another -errno upon other errors.
*/
int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
- u32 requested, struct avc_audit_data *auditdata)
+ u32 requested, struct avc_audit_data *auditdata)
{
struct av_decision avd;
int rc;
- rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, &avd);
+ rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
return rc;
}
+
+u32 avc_policy_seqno(void)
+{
+ return avc_cache.latest_notif;
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff