ext4: unregister es_shrinker if mount failed

[mirror_ubuntu-bionic-kernel.git] / kernel / user_namespace.c

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index b14f4d3420439ca629be08494ef417e734513499..a54f26f82eb250a60c7f24ecc651c6c1bbf8cc88 100644 (file)
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -61,6 +61,15 @@ int create_user_ns(struct cred *new)
        kgid_t group = new->egid;
        int ret;
 
+       /*
+        * Verify that we can not violate the policy of which files
+        * may be accessed that is specified by the root directory,
+        * by verifing that the root directory is at the root of the
+        * mount namespace which allows all files to be accessed.
+        */
+       if (current_chrooted())
+               return -EPERM;
+
        /* The creator needs a mapping in the parent user namespace
         * or else we won't be able to reasonably tell userspace who
         * created a user_namespace.
@@ -87,6 +96,8 @@ int create_user_ns(struct cred *new)
 
        set_cred_user_ns(new, ns);
 
+       update_mnt_policy(ns);
+
        return 0;
 }