Re: [PATCH v6 09/40] xattr: handle idmapped mounts

[David Howells]

Christian Brauner <christian.brauner@xxxxxxxxxx> wrote:

> diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
> index 72e42438f3d7..a591b5e09637 100644
> --- a/fs/cachefiles/xattr.c
> +++ b/fs/cachefiles/xattr.c
> @@ -39,8 +39,8 @@ int cachefiles_check_object_type(struct cachefiles_object *object)
>  	_enter("%p{%s}", object, type);
>  
>  	/* attempt to install a type label directly */
> -	ret = vfs_setxattr(dentry, cachefiles_xattr_cache, type, 2,
> -			   XATTR_CREATE);
> +	ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache, type,
> +			   2, XATTR_CREATE);

Actually, on further consideration, this might be the wrong thing to do in
cachefiles.  The creds are (or should be) overridden when accesses to the
underlying filesystem are being made.

I wonder if this should be using current_cred()->user_ns or
cache->cache_cred->user_ns instead.

David