apparmor: convert profile lists to RCU based locking

Signed-off-by: John Johansen <john.johansen@canonical.com>

4 files changed, 167 insertions, 111 deletions

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 01b7bd669a88..454bcd7f3452 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -144,7 +144,7 @@ static struct aa_profile *__attach_match(const char *name,
         int len = 0;
         struct aa_profile *profile, *candidate = NULL;
 
-        list_for_each_entry(profile, head, base.list) {
+        list_for_each_entry_rcu(profile, head, base.list) {
                 if (profile->flags & PFLAG_NULL)
                         continue;
                 if (profile->xmatch && profile->xmatch_len > len) {
@@ -177,9 +177,9 @@ static struct aa_profile *find_attach(struct aa_namespace *ns,
 {
         struct aa_profile *profile;
 
-        read_lock(&ns->lock);
+        rcu_read_lock();
         profile = aa_get_profile(__attach_match(name, list));
-        read_unlock(&ns->lock);
+        rcu_read_unlock();
 
         return profile;
 }
@@ -641,7 +641,10 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
         if (count) {
                 /* attempting to change into a new hat or switch to a sibling */
                 struct aa_profile *root;
-                root = PROFILE_IS_HAT(profile) ? profile->parent : profile;
+                if (PROFILE_IS_HAT(profile))
+                        root = aa_get_profile_rcu(&profile->parent);
+                else
+                        root = aa_get_profile(profile);
 
                 /* find first matching hat */
                 for (i = 0; i < count && !hat; i++)
@@ -653,6 +656,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
                                         error = -ECHILD;
                                 else
                                         error = -ENOENT;
+                                aa_put_profile(root);
                                 goto out;
                         }
 
@@ -667,6 +671,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
 
                         /* freed below */
                         name = new_compound_name(root->base.hname, hats[0]);
+                        aa_put_profile(root);
                         target = name;
                         /* released below */
                         hat = aa_new_null_profile(profile, 1);
@@ -676,6 +681,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
                                 goto audit;
                         }
                 } else {
+                        aa_put_profile(root);
                         target = hat->base.hname;
                         if (!PROFILE_IS_HAT(hat)) {
                                 info = "target not hat";
diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
index 1ba2ca56a6ef..8fb1488a3cd4 100644
--- a/security/apparmor/include/apparmor.h
+++ b/security/apparmor/include/apparmor.h
@@ -78,6 +78,12 @@ static inline void *kvzalloc(size_t size)
         return __aa_kvmalloc(size, __GFP_ZERO);
 }
 
+/* returns 0 if kref not incremented */
+static inline int kref_get_not0(struct kref *kref)
+{
+        return atomic_inc_not_zero(&kref->refcount);
+}
+
 /**
  * aa_strneq - compare null terminated @str to a non null terminated substring
  * @str: a null terminated string
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index b25491a3046a..82487a853353 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -42,6 +42,8 @@ extern const char *const profile_mode_names[];
 
 #define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT)
 
+#define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)
+
 /*
  * FIXME: currently need a clean way to replace and remove profiles as a
  * set.  It should be done at the namespace level.
@@ -75,6 +77,7 @@ struct aa_profile;
  * @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
  */
 struct aa_policy {
@@ -83,6 +86,7 @@ struct aa_policy {
         struct kref count;
         struct list_head list;
         struct list_head profiles;
+        struct rcu_head rcu;
 };
 
 /* struct aa_ns_acct - accounting of profiles in namespace
@@ -124,7 +128,7 @@ struct aa_ns_acct {
 struct aa_namespace {
         struct aa_policy base;
         struct aa_namespace *parent;
-        rwlock_t lock;
+        struct mutex lock;
         struct aa_ns_acct acct;
         struct aa_profile *unconfined;
         struct list_head sub_ns;
@@ -166,7 +170,7 @@ struct aa_policydb {
  * attachments are determined by profile X transition rules.
  *
  * The @replacedby field is write protected by the profile lock.  Reads
- * are assumed to be atomic, and are done without locking.
+ * are assumed to be atomic.
  *
  * Profiles have a hierarchy where hats and children profiles keep
  * a reference to their parent.
@@ -177,7 +181,7 @@ struct aa_policydb {
  */
 struct aa_profile {
         struct aa_policy base;
-        struct aa_profile *parent;
+        struct aa_profile __rcu *parent;
 
         struct aa_namespace *ns;
         struct aa_profile *replacedby;
@@ -296,6 +300,41 @@ static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
 }
 
 /**
+ * aa_get_profile_not0 - increment refcount on profile @p found via lookup
+ * @p: profile  (MAYBE NULL)
+ *
+ * Returns: pointer to @p if @p is NULL will return NULL
+ * Requires: @p must be held with valid refcount when called
+ */
+static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
+{
+        if (p && kref_get_not0(&p->base.count))
+                return p;
+
+        return NULL;
+}
+
+/**
+ * aa_get_profile_rcu - increment a refcount profile that can be replaced
+ * @p: pointer to profile that can be replaced (NOT NULL)
+ *
+ * Returns: pointer to a refcounted profile.
+ *     else NULL if no profile
+ */
+static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
+{
+        struct aa_profile *c;
+
+        rcu_read_lock();
+        do {
+                c = rcu_dereference(*p);
+        } while (c && !kref_get_not0(&c->base.count));
+        rcu_read_unlock();
+
+        return c;
+}
+
+/**
  * aa_put_profile - decrement refcount on profile @p
  * @p: profile  (MAYBE NULL)
  */
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 407b442c0a2c..25bbbb482bb6 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -153,13 +153,13 @@ static bool policy_init(struct aa_policy *policy, const char *prefix,
 static void policy_destroy(struct aa_policy *policy)
 {
         /* still contains profiles -- invalid */
-        if (!list_empty(&policy->profiles)) {
+        if (on_list_rcu(&policy->profiles)) {
                 AA_ERROR("%s: internal error, "
                          "policy '%s' still contains profiles\n",
                          __func__, policy->name);
                 BUG();
         }
-        if (!list_empty(&policy->list)) {
+        if (on_list_rcu(&policy->list)) {
                 AA_ERROR("%s: internal error, policy '%s' still on list\n",
                          __func__, policy->name);
                 BUG();
@@ -174,7 +174,7 @@ static void policy_destroy(struct aa_policy *policy)
  * @head: list to search  (NOT NULL)
  * @name: name to search for  (NOT NULL)
  *
- * Requires: correct locks for the @head list be held
+ * Requires: rcu_read_lock be held
  *
  * Returns: unrefcounted policy that match @name or NULL if not found
  */
@@ -182,7 +182,7 @@ static struct aa_policy *__policy_find(struct list_head *head, const char *name)
 {
         struct aa_policy *policy;
 
-        list_for_each_entry(policy, head, list) {
+        list_for_each_entry_rcu(policy, head, list) {
                 if (!strcmp(policy->name, name))
                         return policy;
         }
@@ -195,7 +195,7 @@ static struct aa_policy *__policy_find(struct list_head *head, const char *name)
  * @str: string to search for  (NOT NULL)
  * @len: length of match required
  *
- * Requires: correct locks for the @head list be held
+ * Requires: rcu_read_lock be held
  *
  * Returns: unrefcounted policy that match @str or NULL if not found
  *
@@ -207,7 +207,7 @@ static struct aa_policy *__policy_strn_find(struct list_head *head,
 {
         struct aa_policy *policy;
 
-        list_for_each_entry(policy, head, list) {
+        list_for_each_entry_rcu(policy, head, list) {
                 if (aa_strneq(policy->name, str, len))
                         return policy;
         }
@@ -284,7 +284,7 @@ static struct aa_namespace *alloc_namespace(const char *prefix,
                 goto fail_ns;
 
         INIT_LIST_HEAD(&ns->sub_ns);
-        rwlock_init(&ns->lock);
+        mutex_init(&ns->lock);
 
         /* released by free_namespace */
         ns->unconfined = aa_alloc_profile("unconfined");
@@ -350,7 +350,7 @@ void aa_free_namespace_kref(struct kref *kref)
  *
  * Returns: unrefcounted namespace
  *
- * Requires: ns lock be held
+ * Requires: rcu_read_lock be held
  */
 static struct aa_namespace *__aa_find_namespace(struct list_head *head,
                                                 const char *name)
@@ -373,9 +373,9 @@ struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
 {
         struct aa_namespace *ns = NULL;
 
-        read_lock(&root->lock);
+        rcu_read_lock();
         ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
-        read_unlock(&root->lock);
+        rcu_read_unlock();
 
         return ns;
 }
@@ -392,7 +392,7 @@ static struct aa_namespace *aa_prepare_namespace(const char *name)
 
         root = aa_current_profile()->ns;
 
-        write_lock(&root->lock);
+        mutex_lock(&root->lock);
 
         /* if name isn't specified the profile is loaded to the current ns */
         if (!name) {
@@ -405,31 +405,17 @@ static struct aa_namespace *aa_prepare_namespace(const char *name)
         /* released by caller */
         ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
         if (!ns) {
-                /* namespace not found */
-                struct aa_namespace *new_ns;
-                write_unlock(&root->lock);
-                new_ns = alloc_namespace(root->base.hname, name);
-                if (!new_ns)
-                        return NULL;
-                write_lock(&root->lock);
-                /* test for race when new_ns was allocated */
-                ns = __aa_find_namespace(&root->sub_ns, name);
-                if (!ns) {
-                        /* add parent ref */
-                        new_ns->parent = aa_get_namespace(root);
-
-                        list_add(&new_ns->base.list, &root->sub_ns);
-                        /* add list ref */
-                        ns = aa_get_namespace(new_ns);
-                } else {
-                        /* raced so free the new one */
-                        free_namespace(new_ns);
-                        /* get reference on namespace */
-                        aa_get_namespace(ns);
-                }
+                ns = alloc_namespace(root->base.hname, name);
+                if (!ns)
+                        goto out;
+                /* add parent ref */
+                ns->parent = aa_get_namespace(root);
+                list_add_rcu(&ns->base.list, &root->sub_ns);
+                /* add list ref */
+                aa_get_namespace(ns);
         }
 out:
-        write_unlock(&root->lock);
+        mutex_unlock(&root->lock);
 
         /* return ref */
         return ns;
@@ -447,7 +433,7 @@ out:
 static void __list_add_profile(struct list_head *list,
                                struct aa_profile *profile)
 {
-        list_add(&profile->base.list, list);
+        list_add_rcu(&profile->base.list, list);
         /* get list reference */
         aa_get_profile(profile);
 }
@@ -466,10 +452,8 @@ static void __list_add_profile(struct list_head *list,
  */
 static void __list_remove_profile(struct aa_profile *profile)
 {
-        list_del_init(&profile->base.list);
-        if (!(profile->flags & PFLAG_NO_LIST_REF))
-                /* release list reference */
-                aa_put_profile(profile);
+        list_del_rcu(&profile->base.list);
+        aa_put_profile(profile);
 }
 
 static void __profile_list_release(struct list_head *head);
@@ -510,17 +494,40 @@ static void __ns_list_release(struct list_head *head);
  */
 static void destroy_namespace(struct aa_namespace *ns)
 {
+        struct aa_profile *unconfined;
+
         if (!ns)
                 return;
 
-        write_lock(&ns->lock);
+        mutex_lock(&ns->lock);
         /* release all profiles in this namespace */
         __profile_list_release(&ns->base.profiles);
 
         /* release all sub namespaces */
         __ns_list_release(&ns->sub_ns);
 
-        write_unlock(&ns->lock);
+        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);
+
+        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);
 }
 
 /**
@@ -531,26 +538,12 @@ static void destroy_namespace(struct aa_namespace *ns)
  */
 static void __remove_namespace(struct aa_namespace *ns)
 {
-        struct aa_profile *unconfined = ns->unconfined;
-
         /* remove ns from namespace list */
-        list_del_init(&ns->base.list);
-
-        /*
-         * 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);
+        list_del_rcu(&ns->base.list);
 
         destroy_namespace(ns);
 
-        /* release original ns->unconfined ref */
-        aa_put_profile(unconfined);
-        /* release ns->base.list ref, from removal above */
-        aa_put_namespace(ns);
+        call_rcu(&ns->base.rcu, aa_put_ns_rcu);
 }
 
 /**
@@ -614,16 +607,9 @@ static void free_profile(struct aa_profile *profile)
         if (!profile)
                 return;
 
-        if (!list_empty(&profile->base.list)) {
-                AA_ERROR("%s: internal error, "
-                         "profile '%s' still on ns list\n",
-                         __func__, profile->base.name);
-                BUG();
-        }
-
         /* free children profiles */
         policy_destroy(&profile->base);
-        aa_put_profile(profile->parent);
+        aa_put_profile(rcu_access_pointer(profile->parent));
 
         aa_put_namespace(profile->ns);
         kzfree(profile->rename);
@@ -661,6 +647,16 @@ static void free_profile(struct aa_profile *profile)
 }
 
 /**
+ * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref)
+ * @head: rcu_head callback for freeing of a profile  (NOT NULL)
+ */
+static void aa_free_profile_rcu(struct rcu_head *head)
+{
+        struct aa_profile *p = container_of(head, struct aa_profile, base.rcu);
+        free_profile(p);
+}
+
+/**
  * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
  * @kr: kref callback for freeing of a profile  (NOT NULL)
  */
@@ -668,8 +664,7 @@ void aa_free_profile_kref(struct kref *kref)
 {
         struct aa_profile *p = container_of(kref, struct aa_profile,
                                             base.count);
-
-        free_profile(p);
+        call_rcu(&p->base.rcu, aa_free_profile_rcu);
 }
 
 /**
@@ -733,12 +728,12 @@ struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat)
                 profile->flags |= PFLAG_HAT;
 
         /* released on free_profile */
-        profile->parent = aa_get_profile(parent);
+        rcu_assign_pointer(profile->parent, aa_get_profile(parent));
         profile->ns = aa_get_namespace(parent->ns);
 
-        write_lock(&profile->ns->lock);
+        mutex_lock(&profile->ns->lock);
         __list_add_profile(&parent->base.profiles, profile);
-        write_unlock(&profile->ns->lock);
+        mutex_unlock(&profile->ns->lock);
 
         /* refcount released by caller */
         return profile;
@@ -754,7 +749,7 @@ fail:
  * @head: list to search  (NOT NULL)
  * @name: name of profile (NOT NULL)
  *
- * Requires: ns lock protecting list be held
+ * Requires: rcu_read_lock be held
  *
  * Returns: unrefcounted profile ptr, or NULL if not found
  */
@@ -769,7 +764,7 @@ static struct aa_profile *__find_child(struct list_head *head, const char *name)
  * @name: name of profile (NOT NULL)
  * @len: length of @name substring to match
  *
- * Requires: ns lock protecting list be held
+ * Requires: rcu_read_lock be held
  *
  * Returns: unrefcounted profile ptr, or NULL if not found
  */
@@ -790,9 +785,9 @@ struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
 {
         struct aa_profile *profile;
 
-        read_lock(&parent->ns->lock);
+        rcu_read_lock();
         profile = aa_get_profile(__find_child(&parent->base.profiles, name));
-        read_unlock(&parent->ns->lock);
+        rcu_read_unlock();
 
         /* refcount released by caller */
         return profile;
@@ -807,7 +802,7 @@ struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
  * that matches hname does not need to exist, in general this
  * is used to load a new profile.
  *
- * Requires: ns->lock be held
+ * Requires: rcu_read_lock be held
  *
  * Returns: unrefcounted policy or NULL if not found
  */
@@ -839,7 +834,7 @@ static struct aa_policy *__lookup_parent(struct aa_namespace *ns,
  * @base: base list to start looking up profile name from  (NOT NULL)
  * @hname: hierarchical profile name  (NOT NULL)
  *
- * Requires: ns->lock be held
+ * Requires: rcu_read_lock be held
  *
  * Returns: unrefcounted profile pointer or NULL if not found
  *
@@ -878,9 +873,11 @@ struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
 {
         struct aa_profile *profile;
 
-        read_lock(&ns->lock);
-        profile = aa_get_profile(__lookup_profile(&ns->base, hname));
-        read_unlock(&ns->lock);
+        rcu_read_lock();
+        do {
+                profile = __lookup_profile(&ns->base, hname);
+        } while (profile && !aa_get_profile_not0(profile));
+        rcu_read_unlock();
 
         /* the unconfined profile is not in the regular profile list */
         if (!profile && strcmp(hname, "unconfined") == 0)
@@ -1002,7 +999,7 @@ static void __replace_profile(struct aa_profile *old, struct aa_profile *new)
 
         if (!list_empty(&old->base.profiles)) {
                 LIST_HEAD(lh);
-                list_splice_init(&old->base.profiles, &lh);
+                list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);
 
                 list_for_each_entry_safe(child, tmp, &lh, base.list) {
                         struct aa_profile *p;
@@ -1018,20 +1015,24 @@ static void __replace_profile(struct aa_profile *old, struct aa_profile *new)
                         /* inherit @child and its children */
                         /* TODO: update hname of inherited children */
                         /* list refcount transferred to @new */
-                        list_add(&child->base.list, &new->base.profiles);
-                        aa_put_profile(child->parent);
-                        child->parent = aa_get_profile(new);
+                        p = rcu_dereference_protected(child->parent,
+                                             mutex_is_locked(&child->ns->lock));
+                        rcu_assign_pointer(child->parent, aa_get_profile(new));
+                        list_add_rcu(&child->base.list, &new->base.profiles);
+                        aa_put_profile(p);
                 }
         }
 
-        if (!new->parent)
-                new->parent = aa_get_profile(old->parent);
+        if (!rcu_access_pointer(new->parent)) {
+                struct aa_profile *parent = rcu_dereference(old->parent);
+                rcu_assign_pointer(new->parent, aa_get_profile(parent));
+        }
         /* released by free_profile */
         old->replacedby = aa_get_profile(new);
 
         if (list_empty(&new->base.list)) {
                 /* new is not on a list already */
-                list_replace_init(&old->base.list, &new->base.list);
+                list_replace_rcu(&old->base.list, &new->base.list);
                 aa_get_profile(new);
                 aa_put_profile(old);
         } else
@@ -1099,7 +1100,7 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
                 goto fail;
         }
 
-        write_lock(&ns->lock);
+        mutex_lock(&ns->lock);
         /* setup parent and ns info */
         list_for_each_entry(ent, &lh, list) {
                 struct aa_policy *policy;
@@ -1135,11 +1136,12 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
                                 name = ent->new->base.hname;
                                 goto fail_lock;
                         }
-                        ent->new->parent = aa_get_profile(p);
-                } else if (policy != &ns->base)
+                        rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
+                } else if (policy != &ns->base) {
                         /* released on profile replacement or free_profile */
-                        ent->new->parent = aa_get_profile((struct aa_profile *)
-                                                          policy);
+                        struct aa_profile *p = (struct aa_profile *) policy;
+                        rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
+                }
         }
 
         /* do actual replacement */
@@ -1156,13 +1158,16 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
                 } else if (ent->rename) {
                         __replace_profile(ent->rename, ent->new);
                 } else if (ent->new->parent) {
-                        struct aa_profile *parent;
-                        parent = aa_newest_version(ent->new->parent);
+                        struct aa_profile *parent, *newest;
+                        parent = rcu_dereference_protected(ent->new->parent,
+                                                    mutex_is_locked(&ns->lock));
+                        newest = aa_newest_version(parent);
+
                         /* parent replaced in this atomic set? */
-                        if (parent != ent->new->parent) {
-                                aa_get_profile(parent);
-                                aa_put_profile(ent->new->parent);
-                                ent->new->parent = parent;
+                        if (newest != parent) {
+                                aa_get_profile(newest);
+                                aa_put_profile(parent);
+                                rcu_assign_pointer(ent->new->parent, newest);
                         }
                         __list_add_profile(&parent->base.profiles, ent->new);
                 } else
@@ -1170,7 +1175,7 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
 
                 aa_load_ent_free(ent);
         }
-        write_unlock(&ns->lock);
+        mutex_unlock(&ns->lock);
 
 out:
         aa_put_namespace(ns);
@@ -1180,7 +1185,7 @@ out:
         return size;
 
 fail_lock:
-        write_unlock(&ns->lock);
+        mutex_unlock(&ns->lock);
 fail:
         error = audit_policy(op, GFP_KERNEL, name, info, error);
 
@@ -1235,12 +1240,12 @@ ssize_t aa_remove_profiles(char *fqname, size_t size)
 
         if (!name) {
                 /* remove namespace - can only happen if fqname[0] == ':' */
-                write_lock(&ns->parent->lock);
+                mutex_lock(&ns->parent->lock);
                 __remove_namespace(ns);
-                write_unlock(&ns->parent->lock);
+                mutex_unlock(&ns->parent->lock);
         } else {
                 /* remove profile */
-                write_lock(&ns->lock);
+                mutex_lock(&ns->lock);
                 profile = aa_get_profile(__lookup_profile(&ns->base, name));
                 if (!profile) {
                         error = -ENOENT;
@@ -1249,7 +1254,7 @@ ssize_t aa_remove_profiles(char *fqname, size_t size)
                 }
                 name = profile->base.hname;
                 __remove_profile(profile);
-                write_unlock(&ns->lock);
+                mutex_unlock(&ns->lock);
         }
 
         /* don't fail removal if audit fails */
@@ -1259,7 +1264,7 @@ ssize_t aa_remove_profiles(char *fqname, size_t size)
         return size;
 
 fail_ns_lock:
-        write_unlock(&ns->lock);
+        mutex_unlock(&ns->lock);
         aa_put_namespace(ns);
 
 fail: