On Tue, 2010-11-02 at 10:30 +0100, Roberto Sassu wrote:
> The buffer 'derived_buf' in the function get_derived_key() must be
> allocated dynamically in order to make room for an arbitrary length
> master key.
> 
> Signed-off-by: Roberto Sassu <roberto.sa...@polito.it>
> ---
>  security/keys/encrypted_defined.c |   15 +++++++++++++--
>  1 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/security/keys/encrypted_defined.c 
> b/security/keys/encrypted_defined.c
> index 5331925..65d9b13 100644
> --- a/security/keys/encrypted_defined.c
> +++ b/security/keys/encrypted_defined.c
> @@ -289,10 +289,20 @@ enum derived_key_type { ENC_KEY, AUTH_KEY };
>  static int get_derived_key(char *derived_key, enum derived_key_type key_type,
>                          void *master_key, unsigned int master_keylen)
>  {
> -     char derived_buf[hash_size + 10];
> +     char *derived_buf;
>       int ret;
> +     unsigned int derived_buf_len;
> +
> +     derived_buf_len = strlen("AUTH_KEY") + 1 + master_keylen;
> +     if (derived_buf_len < hash_size)
> +             derived_buf_len = hash_size;
> +
> +     derived_buf = kzalloc(derived_buf_len, GFP_KERNEL);
> +     if (!derived_buf) {
> +             pr_err("encrypted_key: out of memory\n");
> +             return -ENOMEM;
> +     }
>  
> -     memset(derived_buf, 0, sizeof derived_buf);

Thanks Roberto!

>       if (key_type)
>               strcpy(derived_buf, "AUTH_KEY");
>       else
> @@ -301,6 +311,7 @@ static int get_derived_key(char *derived_key, enum 
> derived_key_type key_type,
>       memcpy(derived_buf + strlen(derived_buf) + 1, master_key,
>              master_keylen);
>       ret = calc_hash(derived_key, derived_buf, sizeof derived_buf);
> +     kfree(derived_buf);
>       return ret;
>  }
>  

Yes, and the length in calc_hash() would then need to be
derived_buf_len.

thanks,

Mimi

--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to