[dm-devel] [PATCH] dm-crypt: mark key as invalid until properly loaded

[Mikulas Patocka]

On Wed, 2 Nov 2016, Ondrej Kozina wrote:

> on crypt_message() key set code path while loading new key
> replacing the old one in case tfm->setkey() fails
> we would end having invalid key in crypto layer but
> DM_CRYPT_KEY_VALID flag set.
> 
> Signed-off-by: Ondrej Kozina <okozina at redhat.com>

Reviewed-by: Mikulas Patocka <mpatocka at redhat.com>

> ---
>  drivers/md/dm-crypt.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
> index a276883..0aedd0e 100644
> --- a/drivers/md/dm-crypt.c
> +++ b/drivers/md/dm-crypt.c
> @@ -1503,12 +1503,15 @@ static int crypt_set_key(struct crypt_config *cc, char *key)
>  	if (!cc->key_size && strcmp(key, "-"))
>  		goto out;
>  
> +	/* clear the flag since following operations may invalidate previously valid key */
> +	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
> +
>  	if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
>  		goto out;
>  
> -	set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
> -
>  	r = crypt_setkey_allcpus(cc);
> +	if (!r)
> +		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
>  
>  out:
>  	/* Hex key string not needed after here, so wipe it. */
> -- 
> 2.7.4
>