Re: [PATCH v8 05/19] ima: Move measurement list related variables into ima_namespace

[Stefan Berger <stefanb@linux.ibm.com>]

On 1/13/22 15:27, Mimi Zohar wrote:
> Hi Stefan,
>
> On Tue, 2022-01-04 at 12:04 -0500, Stefan Berger wrote:
>> From: Stefan Berger <stefanb@linux.ibm.com>
>>
>> Move measurement list related variables into the ima_namespace. This way a
>> front-end like SecurityFS can show the measurement list inside an IMA
>> namespace.
>>
>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>> ---
>>   security/integrity/ima/ima.h             |  5 +++--
>>   security/integrity/ima/ima_fs.c          |  6 ++++--
>>   security/integrity/ima/ima_init_ima_ns.c |  5 +++++
>>   security/integrity/ima/ima_kexec.c       | 12 +++++++-----
>>   security/integrity/ima/ima_queue.c       | 24 ++++++++++--------------
>>   5 files changed, 29 insertions(+), 23 deletions(-)
>>
>> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
>> index 68d8a8e6fd1d..ee16ce5050c8 100644
>> --- a/security/integrity/ima/ima.h
>> +++ b/security/integrity/ima/ima.h
>> @@ -106,7 +106,6 @@ struct ima_queue_entry {
>>   	struct list_head later;		/* place in ima_measurements list */
>>   	struct ima_template_entry *entry;
>>   };
>> -extern struct list_head ima_measurements;	/* list of all measurements */
>>   
>>   /* Some details preceding the binary serialized measurement list */
>>   struct ima_kexec_hdr {
>> @@ -134,6 +133,8 @@ struct ima_namespace {
>>   	int ima_policy_flag;
>>   
>>   	struct ima_h_table ima_htable;
>> +	struct list_head ima_measurements;
>> +	unsigned long binary_runtime_size;
> Please add a comment indicating binary_runtime_size is only applicable
> to ns_ima_init.

It looks like this now:

         struct list_head ima_measurements;
         /* binary_runtime_size is used only by init_ima_ns */
         unsigned long binary_runtime_size;


>
>
>>   } __randomize_layout;
>>   extern struct ima_namespace init_ima_ns;
>
>> @@ -124,12 +119,13 @@ static int ima_add_digest_entry(struct ima_namespace *ns,
>>    * entire binary_runtime_measurement list, including the ima_kexec_hdr
>>    * structure.
>>    */
>> -unsigned long ima_get_binary_runtime_size(void)
>> +unsigned long ima_get_binary_runtime_size(struct ima_namespace *ns)
>>   {
>> -	if (binary_runtime_size >= (ULONG_MAX - sizeof(struct ima_kexec_hdr)))
>> +	if (ns->binary_runtime_size >=
>> +				(ULONG_MAX - sizeof(struct ima_kexec_hdr)))
>>   		return ULONG_MAX;
>>   	else
>> -		return binary_runtime_size + sizeof(struct ima_kexec_hdr);
>> +		return ns->binary_runtime_size + sizeof(struct ima_kexec_hdr);
>>   }
>>   
> Please update the function description indicating that either carrying
> the measurement list across kexec is limited to ns_ima_init or not
> supported by namespaces.

This is the updated function description:


/*
  * Return the amount of memory required for serializing the
  * entire binary_runtime_measurement list, including the ima_kexec_hdr
  * structure. Carrying the measurement list across kexec is limited
  * to init_ima_ns.
  */
>
> thanks,
>
> Mimi
>