Re: [PATCH 1/2] userns: remove dead key_put() on the create_user_ns() error path

[Jan Kara]

On Fri 28-08-26 17:16:58, Tao Cui wrote:
> From: Tao Cui <cuitao@xxxxxxxxxx>
> 
> create_user_ns() jumps to fail_keyring when setup_userns_sysctls()
> fails.  At that point ns was freshly allocated with
> kmem_cache_zalloc() and ns->persistent_keyring_register is only ever
> assigned later, lazily, from key_get_persistent()
> (security/keys/persistent.c).  The key_put() therefore always
> receives NULL.
> 
> Remove the dead call.
> 
> Signed-off-by: Tao Cui <cuitao@xxxxxxxxxx>

Adding Eric to CC for verification but yes, that code seems to be dead
since its introduction by Eric 10 years ago. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  kernel/user_namespace.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
> index 0bed462e9b2a..e9e04ce167df 100644
> --- a/kernel/user_namespace.c
> +++ b/kernel/user_namespace.c
> @@ -162,9 +162,6 @@ int create_user_ns(struct cred *new)
>  	ns_tree_add(ns);
>  	return 0;
>  fail_keyring:
> -#ifdef CONFIG_PERSISTENT_KEYRINGS
> -	key_put(ns->persistent_keyring_register);
> -#endif
>  	ns_common_free(ns);
>  fail_free:
>  	kmem_cache_free(user_ns_cachep, ns);
> -- 
> 2.43.0
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR