Merge branch 'nsfs-ioctls' into HEAD

[cascardo/linux.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 7bb2cda..8a0e90e 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2719,9 +2719,20 @@ dput_out:
        return retval;
 }
 
+static struct ucounts *inc_mnt_namespaces(struct user_namespace *ns)
+{
+       return inc_ucount(ns, current_euid(), UCOUNT_MNT_NAMESPACES);
+}
+
+static void dec_mnt_namespaces(struct ucounts *ucounts)
+{
+       dec_ucount(ucounts, UCOUNT_MNT_NAMESPACES);
+}
+
 static void free_mnt_ns(struct mnt_namespace *ns)
 {
        ns_free_inum(&ns->ns);
+       dec_mnt_namespaces(ns->ucounts);
        put_user_ns(ns->user_ns);
        kfree(ns);
 }
@@ -2738,14 +2749,22 @@ static atomic64_t mnt_ns_seq = ATOMIC64_INIT(1);
 static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
 {
        struct mnt_namespace *new_ns;
+       struct ucounts *ucounts;
        int ret;
 
+       ucounts = inc_mnt_namespaces(user_ns);
+       if (!ucounts)
+               return ERR_PTR(-ENOSPC);
+
        new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
-       if (!new_ns)
+       if (!new_ns) {
+               dec_mnt_namespaces(ucounts);
                return ERR_PTR(-ENOMEM);
+       }
        ret = ns_alloc_inum(&new_ns->ns);
        if (ret) {
                kfree(new_ns);
+               dec_mnt_namespaces(ucounts);
                return ERR_PTR(ret);
        }
        new_ns->ns.ops = &mntns_operations;
@@ -2756,6 +2775,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
        init_waitqueue_head(&new_ns->poll);
        new_ns->event = 0;
        new_ns->user_ns = get_user_ns(user_ns);
+       new_ns->ucounts = ucounts;
        return new_ns;
 }
 
@@ -3348,10 +3368,16 @@ static int mntns_install(struct nsproxy *nsproxy, struct ns_common *ns)
        return 0;
 }
 
+static struct user_namespace *mntns_owner(struct ns_common *ns)
+{
+       return to_mnt_ns(ns)->user_ns;
+}
+
 const struct proc_ns_operations mntns_operations = {
        .name           = "mnt",
        .type           = CLONE_NEWNS,
        .get            = mntns_get,
        .put            = mntns_put,
        .install        = mntns_install,
+       .owner          = mntns_owner,
 };