Re: [PATCH v8 5/8] ima: make process_buffer_measurement() generic

[Mimi Zohar <zohar@linux.ibm.com>]

On Sat, 2019-10-19 at 14:06 -0400, Nayna Jain wrote:
> process_buffer_measurement() is limited to measuring the kexec boot
> command line. This patch makes process_buffer_measurement() more
> generic, allowing it to measure other types of buffer data (e.g.
> blacklisted binary hashes or key hashes).

based on "func".
> 
> This patch modifies the function to conditionally retrieve the policy
> defined pcr and template based on the func.

This would be done in a subsequent patch, not here.

> @@ -642,19 +642,38 @@ static void process_buffer_measurement(const void *buf, int size,
>  					    .filename = eventname,
>  					    .buf = buf,
>  					    .buf_len = size};
> -	struct ima_template_desc *template_desc = NULL;
> +	struct ima_template_desc *template = NULL;
>  	struct {
>  		struct ima_digest_data hdr;
>  		char digest[IMA_MAX_DIGEST_SIZE];
>  	} hash = {};
>  	int violation = 0;
> -	int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
>  	int action = 0;
> +	u32 secid;
>  
> -	action = ima_get_action(NULL, cred, secid, 0, KEXEC_CMDLINE, &pcr,
> -				&template_desc);
> -	if (!(action & IMA_MEASURE))
> -		return;
> +	if (func) {
> +		security_task_getsecid(current, &secid);
> +		action = ima_get_action(NULL, current_cred(), secid, 0, func,
> +					&pcr, &template);
> +		if (!(action & IMA_MEASURE))
> +			return;
> +	}
> +

Initially there is no need to test "func".  A specific "func" test
would be added as needed. 

Mimi