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-rw-r--r--security/apparmor/domain.c2
-rw-r--r--security/apparmor/include/policy.h80
-rw-r--r--security/apparmor/policy.c68
3 files changed, 67 insertions, 83 deletions
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 5488d095af6f..bc28f2670ee4 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -434,7 +434,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
new_profile = aa_get_profile(profile);
goto x_clear;
} else if (perms.xindex & AA_X_UNCONFINED) {
- new_profile = aa_get_profile(ns->unconfined);
+ new_profile = aa_get_newest_profile(ns->unconfined);
info = "ux fallback";
} else {
error = -ENOENT;
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index e9f2baf4467e..1ddd5e5728b8 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -68,6 +68,7 @@ enum profile_flags {
PFLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */
PFLAG_OLD_NULL_TRANS = 0x100, /* use // as the null transition */
PFLAG_INVALID = 0x200, /* profile replaced/removed */
+ PFLAG_NS_COUNT = 0x400, /* carries NS ref count */
/* These flags must correspond with PATH_flags */
PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */
@@ -78,7 +79,6 @@ struct aa_profile;
/* struct aa_policy - common part of both namespaces and profiles
* @name: name of the object
* @hname - The hierarchical name
- * @count: reference count of the obj
* @list: list policy object is on
* @rcu: rcu head used when removing from @list
* @profiles: head of the profiles list contained in the object
@@ -86,7 +86,6 @@ struct aa_profile;
struct aa_policy {
char *name;
char *hname;
- struct kref count;
struct list_head list;
struct list_head profiles;
struct rcu_head rcu;
@@ -157,6 +156,7 @@ struct aa_replacedby {
/* struct aa_profile - basic confinement data
* @base - base components of the profile (name, refcount, lists, lock ...)
+ * @count: reference count of the obj
* @parent: parent of profile
* @ns: namespace the profile is in
* @replacedby: is set to the profile that replaced this profile
@@ -189,6 +189,7 @@ struct aa_replacedby {
*/
struct aa_profile {
struct aa_policy base;
+ struct kref count;
struct aa_profile __rcu *parent;
struct aa_namespace *ns;
@@ -223,40 +224,6 @@ void aa_free_namespace_kref(struct kref *kref);
struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
const char *name);
-static inline struct aa_policy *aa_get_common(struct aa_policy *c)
-{
- if (c)
- kref_get(&c->count);
-
- return c;
-}
-
-/**
- * aa_get_namespace - increment references count on @ns
- * @ns: namespace to increment reference count of (MAYBE NULL)
- *
- * Returns: pointer to @ns, if @ns is NULL returns NULL
- * Requires: @ns must be held with valid refcount when called
- */
-static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns)
-{
- if (ns)
- kref_get(&(ns->base.count));
-
- return ns;
-}
-
-/**
- * aa_put_namespace - decrement refcount on @ns
- * @ns: namespace to put reference of
- *
- * Decrement reference count of @ns and if no longer in use free it
- */
-static inline void aa_put_namespace(struct aa_namespace *ns)
-{
- if (ns)
- kref_put(&ns->base.count, aa_free_namespace_kref);
-}
void aa_free_replacedby_kref(struct kref *kref);
struct aa_profile *aa_alloc_profile(const char *name);
@@ -285,7 +252,7 @@ ssize_t aa_remove_profiles(char *name, size_t size);
static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
{
if (p)
- kref_get(&(p->base.count));
+ kref_get(&(p->count));
return p;
}
@@ -299,7 +266,7 @@ static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
*/
static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
{
- if (p && kref_get_not0(&p->base.count))
+ if (p && kref_get_not0(&p->count))
return p;
return NULL;
@@ -319,7 +286,7 @@ static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
rcu_read_lock();
do {
c = rcu_dereference(*p);
- } while (c && !kref_get_not0(&c->base.count));
+ } while (c && !kref_get_not0(&c->count));
rcu_read_unlock();
return c;
@@ -350,8 +317,12 @@ static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
*/
static inline void aa_put_profile(struct aa_profile *p)
{
- if (p)
- kref_put(&p->base.count, aa_free_profile_kref);
+ if (p) {
+ if (p->flags & PFLAG_NS_COUNT)
+ kref_put(&p->count, aa_free_namespace_kref);
+ else
+ kref_put(&p->count, aa_free_profile_kref);
+ }
}
static inline struct aa_replacedby *aa_get_replacedby(struct aa_replacedby *p)
@@ -378,6 +349,33 @@ static inline void __aa_update_replacedby(struct aa_profile *orig,
aa_put_profile(tmp);
}
+/**
+ * aa_get_namespace - increment references count on @ns
+ * @ns: namespace to increment reference count of (MAYBE NULL)
+ *
+ * Returns: pointer to @ns, if @ns is NULL returns NULL
+ * Requires: @ns must be held with valid refcount when called
+ */
+static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns)
+{
+ if (ns)
+ aa_get_profile(ns->unconfined);
+
+ return ns;
+}
+
+/**
+ * aa_put_namespace - decrement refcount on @ns
+ * @ns: namespace to put reference of
+ *
+ * Decrement reference count of @ns and if no longer in use free it
+ */
+static inline void aa_put_namespace(struct aa_namespace *ns)
+{
+ if (ns)
+ aa_put_profile(ns->unconfined);
+}
+
static inline int AUDIT_MODE(struct aa_profile *profile)
{
if (aa_g_audit != AUDIT_NORMAL)
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 41b8f275c626..0ceee967434c 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -141,7 +141,6 @@ static bool policy_init(struct aa_policy *policy, const char *prefix,
policy->name = (char *)hname_tail(policy->hname);
INIT_LIST_HEAD(&policy->list);
INIT_LIST_HEAD(&policy->profiles);
- kref_init(&policy->count);
return 1;
}
@@ -292,14 +291,10 @@ static struct aa_namespace *alloc_namespace(const char *prefix,
goto fail_unconfined;
ns->unconfined->flags = PFLAG_UNCONFINED | PFLAG_IX_ON_NAME_ERROR |
- PFLAG_IMMUTABLE;
+ PFLAG_IMMUTABLE | PFLAG_NS_COUNT;
- /*
- * released by free_namespace, however __remove_namespace breaks
- * the cyclic references (ns->unconfined, and unconfined->ns) and
- * replaces with refs to parent namespace unconfined
- */
- ns->unconfined->ns = aa_get_namespace(ns);
+ /* ns and ns->unconfined share ns->unconfined refcount */
+ ns->unconfined->ns = ns;
atomic_set(&ns->uniq_null, 0);
@@ -312,6 +307,7 @@ fail_ns:
return NULL;
}
+static void free_profile(struct aa_profile *profile);
/**
* free_namespace - free a profile namespace
* @ns: the namespace to free (MAYBE NULL)
@@ -327,20 +323,33 @@ static void free_namespace(struct aa_namespace *ns)
policy_destroy(&ns->base);
aa_put_namespace(ns->parent);
- if (ns->unconfined && ns->unconfined->ns == ns)
- ns->unconfined->ns = NULL;
-
- aa_put_profile(ns->unconfined);
+ ns->unconfined->ns = NULL;
+ free_profile(ns->unconfined);
kzfree(ns);
}
/**
+ * aa_free_namespace_rcu - free aa_namespace by rcu
+ * @head: rcu_head callback for freeing of a profile (NOT NULL)
+ *
+ * rcu_head is to the unconfined profile associated with the namespace
+ */
+static void aa_free_namespace_rcu(struct rcu_head *head)
+{
+ struct aa_profile *p = container_of(head, struct aa_profile, base.rcu);
+ free_namespace(p->ns);
+}
+
+/**
* aa_free_namespace_kref - free aa_namespace by kref (see aa_put_namespace)
* @kr: kref callback for freeing of a namespace (NOT NULL)
+ *
+ * kref is to the unconfined profile associated with the namespace
*/
void aa_free_namespace_kref(struct kref *kref)
{
- free_namespace(container_of(kref, struct aa_namespace, base.count));
+ struct aa_profile *p = container_of(kref, struct aa_profile, count);
+ call_rcu(&p->base.rcu, aa_free_namespace_rcu);
}
/**
@@ -494,8 +503,6 @@ static void __ns_list_release(struct list_head *head);
*/
static void destroy_namespace(struct aa_namespace *ns)
{
- struct aa_profile *unconfined;
-
if (!ns)
return;
@@ -506,30 +513,11 @@ static void destroy_namespace(struct aa_namespace *ns)
/* release all sub namespaces */
__ns_list_release(&ns->sub_ns);
- unconfined = ns->unconfined;
- /*
- * break the ns, unconfined profile cyclic reference and forward
- * all new unconfined profiles requests to the parent namespace
- * This will result in all confined tasks that have a profile
- * being removed, inheriting the parent->unconfined profile.
- */
if (ns->parent)
- ns->unconfined = aa_get_profile(ns->parent->unconfined);
-
- /* release original ns->unconfined ref */
- aa_put_profile(unconfined);
-
+ __aa_update_replacedby(ns->unconfined, ns->parent->unconfined);
mutex_unlock(&ns->lock);
}
-static void aa_put_ns_rcu(struct rcu_head *head)
-{
- struct aa_namespace *ns = container_of(head, struct aa_namespace,
- base.rcu);
- /* release ns->base.list ref */
- aa_put_namespace(ns);
-}
-
/**
* __remove_namespace - remove a namespace and all its children
* @ns: namespace to be removed (NOT NULL)
@@ -540,10 +528,8 @@ static void __remove_namespace(struct aa_namespace *ns)
{
/* remove ns from namespace list */
list_del_rcu(&ns->base.list);
-
destroy_namespace(ns);
-
- call_rcu(&ns->base.rcu, aa_put_ns_rcu);
+ aa_put_namespace(ns);
}
/**
@@ -656,8 +642,7 @@ static void aa_free_profile_rcu(struct rcu_head *head)
*/
void aa_free_profile_kref(struct kref *kref)
{
- struct aa_profile *p = container_of(kref, struct aa_profile,
- base.count);
+ struct aa_profile *p = container_of(kref, struct aa_profile, count);
call_rcu(&p->base.rcu, aa_free_profile_rcu);
}
@@ -683,6 +668,7 @@ struct aa_profile *aa_alloc_profile(const char *hname)
if (!policy_init(&profile->base, NULL, hname))
goto fail;
+ kref_init(&profile->count);
/* refcount released by caller */
return profile;
@@ -884,7 +870,7 @@ struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
/* the unconfined profile is not in the regular profile list */
if (!profile && strcmp(hname, "unconfined") == 0)
- profile = aa_get_profile(ns->unconfined);
+ profile = aa_get_newest_profile(ns->unconfined);
/* refcount released by caller */
return profile;
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