[PATCH v7 5/5] IMA: Read keyrings= option from the IMA policy

From: Lakshmi Ramasubramanian
Date: Wed Nov 13 2019 - 22:12:25 EST


Read "keyrings=" option, if specified in the IMA policy, and store in
the list of IMA rules when the configured IMA policy is read.

This patch defines a new policy token enum namely Opt_keyrings
and an option flag IMA_KEYRINGS for reading "keyrings=" option
from the IMA policy.

Updated ima_parse_rule() to parse "keyrings=" option in the policy.
Updated ima_policy_show() to display "keyrings=" option.

Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
---
security/integrity/ima/ima_policy.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 76da4f17bc79..577a51a548fb 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -34,6 +34,7 @@
#define IMA_EUID 0x0080
#define IMA_PCR 0x0100
#define IMA_FSNAME 0x0200
+#define IMA_KEYRINGS 0x0400

#define UNKNOWN 0
#define MEASURE 0x0001 /* same as IMA_MEASURE */
@@ -795,7 +796,8 @@ enum {
Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt,
Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
Opt_appraise_type, Opt_appraise_flag,
- Opt_permit_directio, Opt_pcr, Opt_template, Opt_err
+ Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
+ Opt_err
};

static const match_table_t policy_tokens = {
@@ -831,6 +833,7 @@ static const match_table_t policy_tokens = {
{Opt_permit_directio, "permit_directio"},
{Opt_pcr, "pcr=%s"},
{Opt_template, "template=%s"},
+ {Opt_keyrings, "keyrings=%s"},
{Opt_err, NULL}
};

@@ -1080,6 +1083,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
result = 0;
entry->flags |= IMA_FSNAME;
break;
+ case Opt_keyrings:
+ ima_log_string(ab, "keyrings", args[0].from);
+
+ if ((entry->keyrings) ||
+ (entry->action != MEASURE) ||
+ (entry->func != KEY_CHECK)) {
+ result = -EINVAL;
+ break;
+ }
+ entry->keyrings = kstrdup(args[0].from, GFP_KERNEL);
+ if (!entry->keyrings) {
+ result = -ENOMEM;
+ break;
+ }
+ result = 0;
+ entry->flags |= IMA_KEYRINGS;
+ break;
case Opt_fsuuid:
ima_log_string(ab, "fsuuid", args[0].from);

@@ -1455,6 +1475,13 @@ int ima_policy_show(struct seq_file *m, void *v)
seq_puts(m, " ");
}

+ if (entry->flags & IMA_KEYRINGS) {
+ if (entry->keyrings != NULL)
+ snprintf(tbuf, sizeof(tbuf), "%s", entry->keyrings);
+ seq_printf(m, pt(Opt_keyrings), tbuf);
+ 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