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-rw-r--r--security/selinux/avc.c80
1 files changed, 46 insertions, 34 deletions
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 187964e88af..95a8ef4a507 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -2,16 +2,16 @@
* 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>
@@ -44,7 +44,7 @@ static const char *class_to_string[] = {
#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"
@@ -72,7 +72,7 @@ const struct selinux_class_perm selinux_class_perm = {
#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(); \
@@ -92,7 +92,7 @@ struct avc_entry {
struct avc_node {
struct avc_entry ae;
struct list_head list;
- struct rcu_head rhead;
+ struct rcu_head rhead;
};
struct avc_cache {
@@ -105,8 +105,8 @@ struct avc_cache {
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;
@@ -202,7 +202,7 @@ static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tcla
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 {
@@ -306,12 +306,13 @@ static inline int avc_reclaim_node(void)
int hvalue, try, ecx;
unsigned long flags;
- 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);
if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags))
continue;
+ rcu_read_lock();
list_for_each_entry(node, &avc_cache.slots[hvalue], list) {
if (atomic_dec_and_test(&node->ae.used)) {
/* Recently Unused */
@@ -319,11 +320,13 @@ static inline int avc_reclaim_node(void)
avc_cache_stats_incr(reclaims);
ecx++;
if (ecx >= AVC_CACHE_RECLAIM) {
+ rcu_read_unlock();
spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
goto out;
}
}
}
+ rcu_read_unlock();
spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
}
out:
@@ -426,7 +429,7 @@ 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 "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;
}
@@ -475,7 +478,7 @@ static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_en
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;
}
}
@@ -526,8 +529,8 @@ static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
* 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;
@@ -541,7 +544,7 @@ void avc_audit(u32 ssid, u32 tsid,
return;
} else if (result) {
audited = denied = requested;
- } else {
+ } else {
audited = requested;
if (!(audited & avd->auditallow))
return;
@@ -551,7 +554,7 @@ void avc_audit(u32 ssid, u32 tsid,
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;
@@ -647,7 +650,7 @@ void avc_audit(u32 ssid, u32 tsid,
break;
}
}
-
+
switch (a->u.net.family) {
case AF_INET:
avc_print_ipv4_addr(ab, a->u.net.v4info.saddr,
@@ -702,10 +705,10 @@ void avc_audit(u32 ssid, u32 tsid,
* -%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;
@@ -759,10 +762,10 @@ static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass)
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 ){
+ list_for_each_entry(pos, &avc_cache.slots[hvalue], list) {
+ if (ssid == pos->ae.ssid &&
+ tsid == pos->ae.tsid &&
+ tclass == pos->ae.tclass){
orig = pos;
break;
}
@@ -821,15 +824,21 @@ int avc_ss_reset(u32 seqno)
for (i = 0; i < AVC_CACHE_SLOTS; i++) {
spin_lock_irqsave(&avc_cache.slots_lock[i], flag);
+ /*
+ * With preemptable RCU, the outer spinlock does not
+ * prevent RCU grace periods from ending.
+ */
+ rcu_read_lock();
list_for_each_entry(node, &avc_cache.slots[i], list)
avc_node_delete(node);
+ rcu_read_unlock();
spin_unlock_irqrestore(&avc_cache.slots_lock[i], 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)
@@ -871,16 +880,18 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
int rc = 0;
u32 denied;
+ BUG_ON(!requested);
+
rcu_read_lock();
node = avc_lookup(ssid, tsid, tclass, requested);
if (!node) {
rcu_read_unlock();
- rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd);
+ rc = security_compute_av(ssid, tsid, tclass, requested, &entry.avd);
if (rc)
goto out;
rcu_read_lock();
- node = avc_insert(ssid,tsid,tclass,&entry);
+ node = avc_insert(ssid, tsid, tclass, &entry);
}
p_ae = node ? &node->ae : &entry;
@@ -890,13 +901,14 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
denied = requested & ~(p_ae->avd.allowed);
- if (!requested || denied) {
- if (selinux_enforcing || (flags & AVC_STRICT))
+ 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);
else
- if (node)
- avc_update_node(AVC_CALLBACK_GRANT,requested,
- ssid,tsid,tclass);
+ rc = -EACCES;
}
rcu_read_unlock();
@@ -921,7 +933,7 @@ out:
* 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;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-16 13:58:10 +0000