xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ima: update builtin policies

Browse Source 
This patch defines a builtin measurement policy "tcb", similar to the
existing "ima_tcb", but with additional rules to also measure files
based on the effective uid and to measure files opened with the "read"
mode bit set (eg. read, read-write).

Changing the builtin "ima_tcb" policy could potentially break existing
users.  Instead of defining a new separate boot command line option each
time the builtin measurement policy is modified, this patch defines a
single generic boot command line option "ima_policy=" to specify the
builtin policy and deprecates the use of the builtin ima_tcb policy.

[The "ima_policy=" boot command line option is based on Roberto Sassu's
"ima: added new policy type exec" patch.]

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dr. Greg Wettstein <gw@idfusion.org>
Cc: stable@vger.kernel.org
This commit is contained in:
Mimi Zohar
2015-06-11 20:48:33 -04:00
parent 4351c294b8
commit 24fd03c876
2 changed files with 65 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
security/integrity/ima/ima_policy.c
View File

@@ -44,6 +44,8 @@ enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
};
enum policy_types { ORIGINAL_TCB = 1, DEFAULT_TCB };
struct ima_rule_entry {
struct list_head list;
int action;
@@ -72,7 +74,7 @@ struct ima_rule_entry {
* normal users can easily run the machine out of memory simply building
* and running executables.
*/
static struct ima_rule_entry default_rules[] = {
static struct ima_rule_entry dont_measure_rules[] = {
{.action = DONT_MEASURE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
{.action = DONT_MEASURE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
{.action = DONT_MEASURE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
@@ -83,13 +85,29 @@ static struct ima_rule_entry default_rules[] = {
{.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
{.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC,
.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
{.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC}
};
static struct ima_rule_entry original_measurement_rules[] = {
{.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
.flags = IMA_FUNC | IMA_MASK},
{.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
.flags = IMA_FUNC | IMA_MASK},
{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ, .uid = GLOBAL_ROOT_UID,
.flags = IMA_FUNC | IMA_MASK | IMA_UID},
{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
.uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_MASK | IMA_UID},
{.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
{.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
};
static struct ima_rule_entry default_measurement_rules[] = {
{.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
.flags = IMA_FUNC | IMA_MASK},
{.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
.flags = IMA_FUNC | IMA_MASK},
{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
.uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_EUID},
{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
.uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_UID},
{.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
{.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
};
@@ -121,14 +139,29 @@ static struct list_head *ima_rules;
static DEFINE_MUTEX(ima_rules_mutex);
static bool ima_use_tcb __initdata;
static int ima_policy __initdata;
static int __init default_measure_policy_setup(char *str)
{
ima_use_tcb = 1;
if (ima_policy)
return 1;
ima_policy = ORIGINAL_TCB;
return 1;
}
__setup("ima_tcb", default_measure_policy_setup);
static int __init policy_setup(char *str)
{
if (ima_policy)
return 1;
if (strcmp(str, "tcb") == 0)
ima_policy = DEFAULT_TCB;
return 1;
}
__setup("ima_policy=", policy_setup);
static bool ima_use_appraise_tcb __initdata;
static int __init default_appraise_policy_setup(char *str)
{
@@ -352,13 +385,27 @@ void __init ima_init_policy(void)
{
int i, measure_entries, appraise_entries;
/* if !ima_use_tcb set entries = 0 so we load NO default rules */
measure_entries = ima_use_tcb ? ARRAY_SIZE(default_rules) : 0;
/* if !ima_policy set entries = 0 so we load NO default rules */
measure_entries = ima_policy ? ARRAY_SIZE(dont_measure_rules) : 0;
appraise_entries = ima_use_appraise_tcb ?
ARRAY_SIZE(default_appraise_rules) : 0;
for (i = 0; i < measure_entries; i++)
list_add_tail(&default_rules[i].list, &ima_default_rules);
list_add_tail(&dont_measure_rules[i].list, &ima_default_rules);
switch (ima_policy) {
case ORIGINAL_TCB:
for (i = 0; i < ARRAY_SIZE(original_measurement_rules); i++)
list_add_tail(&original_measurement_rules[i].list,
&ima_default_rules);
break;
case DEFAULT_TCB:
for (i = 0; i < ARRAY_SIZE(default_measurement_rules); i++)
list_add_tail(&default_measurement_rules[i].list,
&ima_default_rules);
default:
break;
}
for (i = 0; i < appraise_entries; i++) {
list_add_tail(&default_appraise_rules[i].list,