@@ -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
@@ -34,6 +34,7 @@
#define IMA_PCR 0x0100
#define IMA_FSNAME 0x0200
#define IMA_KEYRINGS 0x0400
+#define IMA_DATA_SOURCE 0x0800
#define UNKNOWN 0
#define MEASURE 0x0001 /* same as IMA_MEASURE */
@@ -930,7 +931,7 @@ 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 = {
@@ -967,6 +968,7 @@ 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}
};
@@ -1134,7 +1136,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
if (entry->action & ~(MEASURE | DONT_MEASURE))
return false;
- if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR))
+ if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR |
+ IMA_DATA_SOURCE))
return false;
if (ima_rule_contains_lsm_cond(entry))
@@ -1344,6 +1347,23 @@ 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);
@@ -1724,6 +1744,12 @@ 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);
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 | 30 ++++++++++++++++++++++++++-- 2 files changed, 30 insertions(+), 2 deletions(-)