[PATCH v1 3/6] KEYS: ima hook to measure builtin_trusted_keys

Lakshmi Ramasubramanian
2019-10-23T00:18:47Z

Add a new ima hook to measure keys added to builtin_trusted_keys
keyring.

Updated ima_match_rules function to handle the new ima hook.
This is used to determine if ima policy requires measurement
of keys added to builtin_trusted_keys keyring.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
Documentation/ABI/testing/ima_policy | 1 +
security/integrity/ima/ima.h | 1 +
security/integrity/ima/ima_api.c | 1 +
security/integrity/ima/ima_policy.c | 5 ++++-
4 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index fc376a323908..25566c74e679 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -29,6 +29,7 @@ Description:
[FIRMWARE_CHECK]
[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
[KEXEC_CMDLINE]
+ [BUILTIN_TRUSTED_KEYS]
mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
[[^]MAY_EXEC]
fsmagic:= hex value
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index b6847ee1f47a..0d2908036882 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -189,6 +189,7 @@ static inline unsigned long ima_hash_key(u8 *digest)
hook(KEXEC_INITRAMFS_CHECK) \
hook(POLICY_CHECK) \
hook(KEXEC_CMDLINE) \
+ hook(BUILTIN_TRUSTED_KEYS) \
hook(MAX_CHECK)
#define __ima_hook_enumify(ENUM) ENUM,

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index f614e22bf39f..cc04706b7e7a 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -175,6 +175,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
* subj,obj, and type: are LSM specific.
* func: FILE_CHECK | BPRM_CHECK | CREDS_CHECK | MMAP_CHECK | MODULE_CHECK
* | KEXEC_CMDLINE
+ * | BUILTIN_TRUSTED_KEYS
* mask: contains the permission mask
* fsmagic: hex value
*
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 6df7f641ff66..944636076152 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -370,7 +370,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
{
int i;

- if (func == KEXEC_CMDLINE) {
+ if ((func == KEXEC_CMDLINE) || (func == BUILTIN_TRUSTED_KEYS)) {
if ((rule->flags & IMA_FUNC) && (rule->func == func))
return true;
return false;
@@ -959,6 +959,9 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
entry->func = POLICY_CHECK;
else if (strcmp(args[0].from, "KEXEC_CMDLINE") == 0)
entry->func = KEXEC_CMDLINE;
+ else if (strcmp(args[0].from,
+ "BUILTIN_TRUSTED_KEYS") == 0)
+ entry->func = BUILTIN_TRUSTED_KEYS;
else
result = -EINVAL;
if (!result)
--
2.17.1