Re: [PATCH v9 7/8] IMA: define a builtin critical data measurement policy

2021-01-05 Thread Tushar Sugandhi 




On 2020-12-24 6:41 a.m., Mimi Zohar wrote:

On Sat, 2020-12-12 at 10:02 -0800, Tushar Sugandhi wrote:

From: Lakshmi Ramasubramanian 

Define a new critical data builtin policy to allow measuring
early kernel integrity critical data before a custom IMA policy
is loaded.

Add critical data to built-in IMA rules if the kernel command line
contains "ima_policy=critical_data".


This sentence isn't really necessary.


Will remove.


Update the documentation on kernel parameters to document
the new critical data builtin policy.

Signed-off-by: Lakshmi Ramasubramanian 
Reviewed-by: Tyler Hicks 


Otherwise,
Reviewed-by:  Mimi Zohar 

Thanks again for the "Reviewed-by" tag.

Thanks,
Tushar


thanks,

Mimi

Re: [PATCH v9 7/8] IMA: define a builtin critical data measurement policy

2020-12-24 Thread Mimi Zohar 
On Sat, 2020-12-12 at 10:02 -0800, Tushar Sugandhi wrote:
> From: Lakshmi Ramasubramanian 
> 
> Define a new critical data builtin policy to allow measuring
> early kernel integrity critical data before a custom IMA policy
> is loaded.
> 
> Add critical data to built-in IMA rules if the kernel command line
> contains "ima_policy=critical_data".

This sentence isn't really necessary.

> 
> Update the documentation on kernel parameters to document
> the new critical data builtin policy.
> 
> Signed-off-by: Lakshmi Ramasubramanian 
> Reviewed-by: Tyler Hicks 

Otherwise,
Reviewed-by:  Mimi Zohar 

thanks,

Mimi

[PATCH v9 7/8] IMA: define a builtin critical data measurement policy

2020-12-12 Thread Tushar Sugandhi 
From: Lakshmi Ramasubramanian 

Define a new critical data builtin policy to allow measuring
early kernel integrity critical data before a custom IMA policy
is loaded.

Add critical data to built-in IMA rules if the kernel command line
contains "ima_policy=critical_data".

Update the documentation on kernel parameters to document
the new critical data builtin policy.

Signed-off-by: Lakshmi Ramasubramanian 
Reviewed-by: Tyler Hicks 
---
 Documentation/admin-guide/kernel-parameters.txt |  5 -
 security/integrity/ima/ima_policy.c | 12 
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt 
b/Documentation/admin-guide/kernel-parameters.txt
index 526d65d8573a..6034d75c3ca0 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1746,7 +1746,7 @@
ima_policy= [IMA]
The builtin policies to load during IMA setup.
Format: "tcb | appraise_tcb | secure_boot |
-fail_securely"
+fail_securely | critical_data"
 
The "tcb" policy measures all programs exec'd, files
mmap'd for exec, and all files opened with the read
@@ -1765,6 +1765,9 @@
filesystems with the SB_I_UNVERIFIABLE_SIGNATURE
flag.
 
+   The "critical_data" policy measures kernel integrity
+   critical data.
+
ima_tcb [IMA] Deprecated.  Use ima_policy= instead.
Load a policy which meets the needs of the Trusted
Computing Base.  This means IMA will measure all
diff --git a/security/integrity/ima/ima_policy.c 
b/security/integrity/ima/ima_policy.c
index fea996a9e26c..376b625acc72 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -206,6 +206,10 @@ static struct ima_rule_entry secure_boot_rules[] 
__ro_after_init = {
 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 };
 
+static struct ima_rule_entry critical_data_rules[] __ro_after_init = {
+   {.action = MEASURE, .func = CRITICAL_DATA, .flags = IMA_FUNC},
+};
+
 /* An array of architecture specific rules */
 static struct ima_rule_entry *arch_policy_entry __ro_after_init;
 
@@ -228,6 +232,7 @@ __setup("ima_tcb", default_measure_policy_setup);
 
 static bool ima_use_appraise_tcb __initdata;
 static bool ima_use_secure_boot __initdata;
+static bool ima_use_critical_data __initdata;
 static bool ima_fail_unverifiable_sigs __ro_after_init;
 static int __init policy_setup(char *str)
 {
@@ -242,6 +247,8 @@ static int __init policy_setup(char *str)
ima_use_appraise_tcb = true;
else if (strcmp(p, "secure_boot") == 0)
ima_use_secure_boot = true;
+   else if (strcmp(p, "critical_data") == 0)
+   ima_use_critical_data = true;
else if (strcmp(p, "fail_securely") == 0)
ima_fail_unverifiable_sigs = true;
else
@@ -872,6 +879,11 @@ void __init ima_init_policy(void)
  ARRAY_SIZE(default_appraise_rules),
  IMA_DEFAULT_POLICY);
 
+   if (ima_use_critical_data)
+   add_rules(critical_data_rules,
+ ARRAY_SIZE(critical_data_rules),
+ IMA_DEFAULT_POLICY);
+
ima_update_policy_flag();
 }
 
-- 
2.17.1