Merge branch 'nsfs-ioctls' into HEAD

[cascardo/linux.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 86b0e8b..d650433 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -6295,6 +6295,16 @@ void cgroup_sk_free(struct sock_cgroup_data *skcd)
 
 /* cgroup namespaces */
 
+static struct ucounts *inc_cgroup_namespaces(struct user_namespace *ns)
+{
+       return inc_ucount(ns, current_euid(), UCOUNT_CGROUP_NAMESPACES);
+}
+
+static void dec_cgroup_namespaces(struct ucounts *ucounts)
+{
+       dec_ucount(ucounts, UCOUNT_CGROUP_NAMESPACES);
+}
+
 static struct cgroup_namespace *alloc_cgroup_ns(void)
 {
        struct cgroup_namespace *new_ns;
@@ -6316,6 +6326,7 @@ static struct cgroup_namespace *alloc_cgroup_ns(void)
 void free_cgroup_ns(struct cgroup_namespace *ns)
 {
        put_css_set(ns->root_cset);
+       dec_cgroup_namespaces(ns->ucounts);
        put_user_ns(ns->user_ns);
        ns_free_inum(&ns->ns);
        kfree(ns);
@@ -6327,6 +6338,7 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
                                        struct cgroup_namespace *old_ns)
 {
        struct cgroup_namespace *new_ns;
+       struct ucounts *ucounts;
        struct css_set *cset;
 
        BUG_ON(!old_ns);
@@ -6340,6 +6352,10 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
        if (!ns_capable(user_ns, CAP_SYS_ADMIN))
                return ERR_PTR(-EPERM);
 
+       ucounts = inc_cgroup_namespaces(user_ns);
+       if (!ucounts)
+               return ERR_PTR(-ENOSPC);
+
        /* It is not safe to take cgroup_mutex here */
        spin_lock_irq(&css_set_lock);
        cset = task_css_set(current);
@@ -6349,10 +6365,12 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
        new_ns = alloc_cgroup_ns();
        if (IS_ERR(new_ns)) {
                put_css_set(cset);
+               dec_cgroup_namespaces(ucounts);
                return new_ns;
        }
 
        new_ns->user_ns = get_user_ns(user_ns);
+       new_ns->ucounts = ucounts;
        new_ns->root_cset = cset;
 
        return new_ns;