userns: Convert user specfied uids and gids in chown into kuids and kgid

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/fs/open.c b/fs/open.c
index 92335f663545..e16680138323 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -506,15 +506,24 @@ static int chown_common(struct path *path, uid_t user, gid_t group)
         struct inode *inode = path->dentry->d_inode;
         int error;
         struct iattr newattrs;
+        kuid_t uid;
+        kgid_t gid;
+
+        uid = make_kuid(current_user_ns(), user);
+        gid = make_kgid(current_user_ns(), group);
 
         newattrs.ia_valid =  ATTR_CTIME;
         if (user != (uid_t) -1) {
+                if (!uid_valid(uid))
+                        return -EINVAL;
                 newattrs.ia_valid |= ATTR_UID;
-                newattrs.ia_uid = user;
+                newattrs.ia_uid = uid;
         }
         if (group != (gid_t) -1) {
+                if (!gid_valid(gid))
+                        return -EINVAL;
                 newattrs.ia_valid |= ATTR_GID;
-                newattrs.ia_gid = group;
+                newattrs.ia_gid = gid;
         }
         if (!S_ISDIR(inode->i_mode))
                 newattrs.ia_valid |=