1 files changed, 4 insertions, 2 deletions

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 9451b12a9b6c..1e34de2fbd60 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -812,14 +812,16 @@ static bool new_idmap_permitted(const struct file *file,
                                 struct user_namespace *ns, int cap_setid,
                                 struct uid_gid_map *new_map)
 {
+        const struct cred *cred = file->f_cred;
         /* Don't allow mappings that would allow anything that wouldn't
          * be allowed without the establishment of unprivileged mappings.
          */
-        if ((new_map->nr_extents == 1) && (new_map->extent[0].count == 1)) {
+        if ((new_map->nr_extents == 1) && (new_map->extent[0].count == 1) &&
+            uid_eq(ns->owner, cred->euid)) {
                 u32 id = new_map->extent[0].lower_first;
                 if (cap_setid == CAP_SETUID) {
                         kuid_t uid = make_kuid(ns->parent, id);
-                        if (uid_eq(uid, file->f_cred->euid))
+                        if (uid_eq(uid, cred->euid))
                                 return true;
                 }
         }