Re: [PATCH] KEYS: reuse keyring_index_key::desc_len in lookup_user_key()

[Eric Biggers <ebiggers@kernel.org>]

On Fri, Nov 02, 2018 at 07:10:49PM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> When lookup_user_key() checks whether the key is possessed, it should
> use the key's existing index_key including the 'desc_len' field, rather
> than recomputing the 'desc_len'.  This shouldn't cause any observable
> behavior change; this way is just simpler and faster.
> 
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  security/keys/process_keys.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
> index d5b25e535d3a5..3bea09e7176d7 100644
> --- a/security/keys/process_keys.c
> +++ b/security/keys/process_keys.c
> @@ -688,9 +688,7 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
>  		key_ref = make_key_ref(key, 0);
>  
>  		/* check to see if we possess the key */
> -		ctx.index_key.type		= key->type;
> -		ctx.index_key.description	= key->description;
> -		ctx.index_key.desc_len		= strlen(key->description);
> +		ctx.index_key			= key->index_key;
>  		ctx.match_data.raw_data		= key;
>  		kdebug("check possessed");
>  		skey_ref = search_process_keyrings(&ctx);
> -- 
> 2.19.1
> 

Ping.