The patch below does not apply to the 4.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 24fd03c87695a76f0517df42a37e51b1597d2c8a Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Date: Thu, 11 Jun 2015 20:48:33 -0400
Subject: [PATCH] ima: update builtin policies
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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Dr. Greg Wettstein <gw@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index abc496f95220..807b765087d4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1398,7 +1398,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
The list of supported hash algorithms is defined
in crypto/hash_info.h.
- ima_tcb [IMA]
+ ima_policy= [IMA]
+ The builtin measurement policy to load during IMA
+ setup. Specyfing "tcb" as the value, measures all
+ programs exec'd, files mmap'd for exec, and all files
+ opened with the read mode bit set by either the
+ effective uid (euid=0) or uid=0.
+ Format: "tcb"
+
+ 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
programs exec'd, files mmap'd for exec, and all files
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index b3a2038ed424..3997e206f82d 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -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 = 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_MASK | IMA_UID},
+ {.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,
--
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