sit: allow to configure 6rd tunnels via netlink

[~andy/linux] / kernel / pid_namespace.c

diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 478bad2745e3a8357fcc2f9a56059d167bf67e49..7b07cc0dfb75fb6b2f2f802178abf82565d9c1a4 100644 (file)
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -71,12 +71,22 @@ err_alloc:
        return NULL;
 }
 
+/* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */
+#define MAX_PID_NS_LEVEL 32
+
 static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_pid_ns)
 {
        struct pid_namespace *ns;
        unsigned int level = parent_pid_ns->level + 1;
-       int i, err = -ENOMEM;
+       int i;
+       int err;
+
+       if (level > MAX_PID_NS_LEVEL) {
+               err = -EINVAL;
+               goto out;
+       }
 
+       err = -ENOMEM;
        ns = kmem_cache_zalloc(pid_ns_cachep, GFP_KERNEL);
        if (ns == NULL)
                goto out;
@@ -133,19 +143,26 @@ struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old
        return create_pid_namespace(old_ns);
 }
 
-void free_pid_ns(struct kref *kref)
+static void free_pid_ns(struct kref *kref)
 {
-       struct pid_namespace *ns, *parent;
+       struct pid_namespace *ns;
 
        ns = container_of(kref, struct pid_namespace, kref);
-
-       parent = ns->parent;
        destroy_pid_namespace(ns);
+}
+
+void put_pid_ns(struct pid_namespace *ns)
+{
+       struct pid_namespace *parent;
 
-       if (parent != NULL)
-               put_pid_ns(parent);
+       while (ns != &init_pid_ns) {
+               parent = ns->parent;
+               if (!kref_put(&ns->kref, free_pid_ns))
+                       break;
+               ns = parent;
+       }
 }
-EXPORT_SYMBOL_GPL(free_pid_ns);
+EXPORT_SYMBOL_GPL(put_pid_ns);
 
 void zap_pid_ns_processes(struct pid_namespace *pid_ns)
 {