[PATCH v5 07/10] KEYS: Call the IMA hook to measure key when a new key is created or an existing key is updated

Lakshmi Ramasubramanian
2019-11-11T19:33:28Z

key_create_or_update function needs to call the IMA hook to measure
the key when a new key is created or an existing key is updated.

This patch adds the call to the IMA hook from key_create_or_update
function.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
include/linux/ima.h | 13 +++++++++++++
security/keys/key.c | 9 +++++++++
2 files changed, 22 insertions(+)

diff --git a/include/linux/ima.h b/include/linux/ima.h
index 6d904754d858..ec5afe319ab7 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -25,6 +25,12 @@ extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
extern void ima_post_path_mknod(struct dentry *dentry);
extern void ima_kexec_cmdline(const void *buf, int size);

+#ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
+extern void ima_post_key_create_or_update(struct key *keyring,
+ struct key *key,
+ unsigned long flags, bool create);
+#endif
+
#ifdef CONFIG_IMA_KEXEC
extern void ima_add_kexec_buffer(struct kimage *image);
#endif
@@ -101,6 +107,13 @@ static inline void ima_add_kexec_buffer(struct kimage *image)
{}
#endif

+#ifndef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
+static inline void ima_post_key_create_or_update(struct key *keyring,
+ struct key *key,
+ unsigned long flags,
+ bool create) {}
+#endif
+
#ifdef CONFIG_IMA_APPRAISE
extern bool is_ima_appraise_enabled(void);
extern void ima_inode_post_setattr(struct dentry *dentry);
diff --git a/security/keys/key.c b/security/keys/key.c
index 764f4c57913e..9782d4d046fd 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -13,6 +13,7 @@
#include <linux/security.h>
#include <linux/workqueue.h>
#include <linux/random.h>
+#include <linux/ima.h>
#include <linux/err.h>
#include "internal.h"

@@ -936,6 +937,9 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
goto error_link_end;
}

+ /* let the ima module know about the created key. */
+ ima_post_key_create_or_update(keyring, key, flags, true);
+
key_ref = make_key_ref(key, is_key_possessed(keyring_ref));

error_link_end:
@@ -965,6 +969,11 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
}

key_ref = __key_update(key_ref, &prep);
+
+ /* let the ima module know about the updated key. */
+ if (!IS_ERR(key_ref))
+ ima_post_key_create_or_update(keyring, key, flags, false);
+
goto error_free_prep;
}
EXPORT_SYMBOL(key_create_or_update);
--
2.17.1