diff mbox series

[v7,5/8] IMA: limit critical data measurement based on a label

Message ID 20201209194212.5131-6-tusharsu@linux.microsoft.com (mailing list archive)
State New
Headers show
Series IMA: support for measuring kernel integrity critical data | expand

Commit Message

Tushar Sugandhi Dec. 9, 2020, 7:42 p.m. UTC
System administrators should be able to limit which kernel subsystems
they want to measure the critical data for. To enable that, an IMA policy
condition to choose specific kernel subsystems is needed. This policy
condition would constrain the measurement of the critical data based on
a label for the given subsystems.

Add a new IMA policy condition - "data_source:=" to the IMA func
CRITICAL_DATA to allow measurement of various kernel subsystems. This
policy condition would enable the system administrators to restrict the
measurement to the labels listed in "data_source:=".

Limit the measurement to the labels that are specified in the IMA
policy - CRITICAL_DATA+"data_source:=". If "data_sources:=" is not
provided with the func CRITICAL_DATA, the data from all the
supported kernel subsystems is measured.

Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
---
 Documentation/ABI/testing/ima_policy |  2 ++
 security/integrity/ima/ima_policy.c  | 26 +++++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

Comments

Tyler Hicks Dec. 10, 2020, 11:15 p.m. UTC | #1
On 2020-12-09 11:42:09, Tushar Sugandhi wrote:
> System administrators should be able to limit which kernel subsystems
> they want to measure the critical data for. To enable that, an IMA policy
> condition to choose specific kernel subsystems is needed. This policy
> condition would constrain the measurement of the critical data based on
> a label for the given subsystems.
> 
> Add a new IMA policy condition - "data_source:=" to the IMA func
> CRITICAL_DATA to allow measurement of various kernel subsystems. This
> policy condition would enable the system administrators to restrict the
> measurement to the labels listed in "data_source:=".
> 
> Limit the measurement to the labels that are specified in the IMA
> policy - CRITICAL_DATA+"data_source:=". If "data_sources:=" is not
> provided with the func CRITICAL_DATA, the data from all the
> supported kernel subsystems is measured.
> 
> Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>

This patch will look good once all the IMA_DATA_SOURCE stuff is moved
over from patch #4.

Tyler

> ---
>  Documentation/ABI/testing/ima_policy |  2 ++
>  security/integrity/ima/ima_policy.c  | 26 +++++++++++++++++++++++++-
>  2 files changed, 27 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
> index 6ec7daa87cba..0f4ee9e0a455 100644
> --- a/Documentation/ABI/testing/ima_policy
> +++ b/Documentation/ABI/testing/ima_policy
> @@ -52,6 +52,8 @@ Description:
>  			template:= name of a defined IMA template type
>  			(eg, ima-ng). Only valid when action is "measure".
>  			pcr:= decimal value
> +			data_source:= [label]
> +			label:= a unique string used for grouping and limiting critical data.
>  
>  		  default policy:
>  			# PROC_SUPER_MAGIC
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 9a8ee80a3128..7486d09a3f60 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -934,7 +934,7 @@ enum {
>  	Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
>  	Opt_appraise_type, Opt_appraise_flag,
>  	Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
> -	Opt_err
> +	Opt_data_source, Opt_err
>  };
>  
>  static const match_table_t policy_tokens = {
> @@ -971,6 +971,7 @@ static const match_table_t policy_tokens = {
>  	{Opt_pcr, "pcr=%s"},
>  	{Opt_template, "template=%s"},
>  	{Opt_keyrings, "keyrings=%s"},
> +	{Opt_data_source, "data_source=%s"},
>  	{Opt_err, NULL}
>  };
>  
> @@ -1350,6 +1351,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
>  
>  			entry->flags |= IMA_KEYRINGS;
>  			break;
> +		case Opt_data_source:
> +			ima_log_string(ab, "data_source", args[0].from);
> +
> +			if (entry->data_source) {
> +				result = -EINVAL;
> +				break;
> +			}
> +
> +			entry->data_source = ima_alloc_rule_opt_list(args);
> +			if (IS_ERR(entry->data_source)) {
> +				result = PTR_ERR(entry->data_source);
> +				entry->data_source = NULL;
> +				break;
> +			}
> +
> +			entry->flags |= IMA_DATA_SOURCE;
> +			break;
>  		case Opt_fsuuid:
>  			ima_log_string(ab, "fsuuid", args[0].from);
>  
> @@ -1730,6 +1748,12 @@ int ima_policy_show(struct seq_file *m, void *v)
>  		seq_puts(m, " ");
>  	}
>  
> +	if (entry->flags & IMA_DATA_SOURCE) {
> +		seq_puts(m, "data_source=");
> +		ima_show_rule_opt_list(m, entry->data_source);
> +		seq_puts(m, " ");
> +	}
> +
>  	if (entry->flags & IMA_PCR) {
>  		snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
>  		seq_printf(m, pt(Opt_pcr), tbuf);
> -- 
> 2.17.1
>
Tushar Sugandhi Dec. 11, 2020, 3:28 a.m. UTC | #2
On 2020-12-10 3:15 p.m., Tyler Hicks wrote:
> On 2020-12-09 11:42:09, Tushar Sugandhi wrote:
>> System administrators should be able to limit which kernel subsystems
>> they want to measure the critical data for. To enable that, an IMA policy
>> condition to choose specific kernel subsystems is needed. This policy
>> condition would constrain the measurement of the critical data based on
>> a label for the given subsystems.
>>
>> Add a new IMA policy condition - "data_source:=" to the IMA func
>> CRITICAL_DATA to allow measurement of various kernel subsystems. This
>> policy condition would enable the system administrators to restrict the
>> measurement to the labels listed in "data_source:=".
>>
>> Limit the measurement to the labels that are specified in the IMA
>> policy - CRITICAL_DATA+"data_source:=". If "data_sources:=" is not
>> provided with the func CRITICAL_DATA, the data from all the
>> supported kernel subsystems is measured.
>>
>> Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
> 
> This patch will look good once all the IMA_DATA_SOURCE stuff is moved
> over from patch #4.
> 
> Tyler
> 
Sounds good. Will do.
~Tushar

>> ---
>>   Documentation/ABI/testing/ima_policy |  2 ++
>>   security/integrity/ima/ima_policy.c  | 26 +++++++++++++++++++++++++-
>>   2 files changed, 27 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
>> index 6ec7daa87cba..0f4ee9e0a455 100644
>> --- a/Documentation/ABI/testing/ima_policy
>> +++ b/Documentation/ABI/testing/ima_policy
>> @@ -52,6 +52,8 @@ Description:
>>   			template:= name of a defined IMA template type
>>   			(eg, ima-ng). Only valid when action is "measure".
>>   			pcr:= decimal value
>> +			data_source:= [label]
>> +			label:= a unique string used for grouping and limiting critical data.
>>   
>>   		  default policy:
>>   			# PROC_SUPER_MAGIC
>> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
>> index 9a8ee80a3128..7486d09a3f60 100644
>> --- a/security/integrity/ima/ima_policy.c
>> +++ b/security/integrity/ima/ima_policy.c
>> @@ -934,7 +934,7 @@ enum {
>>   	Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
>>   	Opt_appraise_type, Opt_appraise_flag,
>>   	Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
>> -	Opt_err
>> +	Opt_data_source, Opt_err
>>   };
>>   
>>   static const match_table_t policy_tokens = {
>> @@ -971,6 +971,7 @@ static const match_table_t policy_tokens = {
>>   	{Opt_pcr, "pcr=%s"},
>>   	{Opt_template, "template=%s"},
>>   	{Opt_keyrings, "keyrings=%s"},
>> +	{Opt_data_source, "data_source=%s"},
>>   	{Opt_err, NULL}
>>   };
>>   
>> @@ -1350,6 +1351,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
>>   
>>   			entry->flags |= IMA_KEYRINGS;
>>   			break;
>> +		case Opt_data_source:
>> +			ima_log_string(ab, "data_source", args[0].from);
>> +
>> +			if (entry->data_source) {
>> +				result = -EINVAL;
>> +				break;
>> +			}
>> +
>> +			entry->data_source = ima_alloc_rule_opt_list(args);
>> +			if (IS_ERR(entry->data_source)) {
>> +				result = PTR_ERR(entry->data_source);
>> +				entry->data_source = NULL;
>> +				break;
>> +			}
>> +
>> +			entry->flags |= IMA_DATA_SOURCE;
>> +			break;
>>   		case Opt_fsuuid:
>>   			ima_log_string(ab, "fsuuid", args[0].from);
>>   
>> @@ -1730,6 +1748,12 @@ int ima_policy_show(struct seq_file *m, void *v)
>>   		seq_puts(m, " ");
>>   	}
>>   
>> +	if (entry->flags & IMA_DATA_SOURCE) {
>> +		seq_puts(m, "data_source=");
>> +		ima_show_rule_opt_list(m, entry->data_source);
>> +		seq_puts(m, " ");
>> +	}
>> +
>>   	if (entry->flags & IMA_PCR) {
>>   		snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
>>   		seq_printf(m, pt(Opt_pcr), tbuf);
>> -- 
>> 2.17.1
>>
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index 6ec7daa87cba..0f4ee9e0a455 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -52,6 +52,8 @@  Description:
 			template:= name of a defined IMA template type
 			(eg, ima-ng). Only valid when action is "measure".
 			pcr:= decimal value
+			data_source:= [label]
+			label:= a unique string used for grouping and limiting critical data.
 
 		  default policy:
 			# PROC_SUPER_MAGIC
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 9a8ee80a3128..7486d09a3f60 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -934,7 +934,7 @@  enum {
 	Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
 	Opt_appraise_type, Opt_appraise_flag,
 	Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
-	Opt_err
+	Opt_data_source, Opt_err
 };
 
 static const match_table_t policy_tokens = {
@@ -971,6 +971,7 @@  static const match_table_t policy_tokens = {
 	{Opt_pcr, "pcr=%s"},
 	{Opt_template, "template=%s"},
 	{Opt_keyrings, "keyrings=%s"},
+	{Opt_data_source, "data_source=%s"},
 	{Opt_err, NULL}
 };
 
@@ -1350,6 +1351,23 @@  static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 
 			entry->flags |= IMA_KEYRINGS;
 			break;
+		case Opt_data_source:
+			ima_log_string(ab, "data_source", args[0].from);
+
+			if (entry->data_source) {
+				result = -EINVAL;
+				break;
+			}
+
+			entry->data_source = ima_alloc_rule_opt_list(args);
+			if (IS_ERR(entry->data_source)) {
+				result = PTR_ERR(entry->data_source);
+				entry->data_source = NULL;
+				break;
+			}
+
+			entry->flags |= IMA_DATA_SOURCE;
+			break;
 		case Opt_fsuuid:
 			ima_log_string(ab, "fsuuid", args[0].from);
 
@@ -1730,6 +1748,12 @@  int ima_policy_show(struct seq_file *m, void *v)
 		seq_puts(m, " ");
 	}
 
+	if (entry->flags & IMA_DATA_SOURCE) {
+		seq_puts(m, "data_source=");
+		ima_show_rule_opt_list(m, entry->data_source);
+		seq_puts(m, " ");
+	}
+
 	if (entry->flags & IMA_PCR) {
 		snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
 		seq_printf(m, pt(Opt_pcr), tbuf);