[PATCH v7 5/8] ima: make process_buffer_measurement() generic

From: Nayna Jain
Date: Mon Oct 07 2019 - 21:15:14 EST


An additional measurement record is needed to indicate the blacklisted
binary. The record will measure the blacklisted binary hash.

This patch makes the function process_buffer_measurement() generic to be
called by the blacklisting function. It modifies the function to handle
more than just the KEXEC_CMDLINE.

Signed-off-by: Nayna Jain <nayna@xxxxxxxxxxxxx>
---
security/integrity/ima/ima.h | 3 +++
security/integrity/ima/ima_main.c | 29 ++++++++++++++---------------
2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 3689081aaf38..ed86c1f70d7f 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -217,6 +217,9 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
struct evm_ima_xattr_data *xattr_value,
int xattr_len, const struct modsig *modsig, int pcr,
struct ima_template_desc *template_desc);
+void process_buffer_measurement(const void *buf, int size,
+ const char *eventname, int pcr,
+ struct ima_template_desc *template_desc);
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename);
int ima_alloc_init_template(struct ima_event_data *event_data,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 60027c643ecd..77115e884496 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -626,14 +626,14 @@ int ima_load_data(enum kernel_load_data_id id)
* @buf: pointer to the buffer that needs to be added to the log.
* @size: size of buffer(in bytes).
* @eventname: event name to be used for the buffer entry.
- * @cred: a pointer to a credentials structure for user validation.
- * @secid: the secid of the task to be validated.
+ * @pcr: pcr to extend the measurement
+ * @template_desc: template description
*
* Based on policy, the buffer is measured into the ima log.
*/
-static void process_buffer_measurement(const void *buf, int size,
- const char *eventname,
- const struct cred *cred, u32 secid)
+void process_buffer_measurement(const void *buf, int size,
+ const char *eventname, int pcr,
+ struct ima_template_desc *template_desc)
{
int ret = 0;
struct ima_template_entry *entry = NULL;
@@ -642,19 +642,11 @@ static void process_buffer_measurement(const void *buf, int size,
.filename = eventname,
.buf = buf,
.buf_len = size};
- struct ima_template_desc *template_desc = NULL;
struct {
struct ima_digest_data hdr;
char digest[IMA_MAX_DIGEST_SIZE];
} hash = {};
int violation = 0;
- int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
- int action = 0;
-
- action = ima_get_action(NULL, cred, secid, 0, KEXEC_CMDLINE, &pcr,
- &template_desc);
- if (!(action & IMA_MEASURE))
- return;

iint.ima_hash = &hash.hdr;
iint.ima_hash->algo = ima_hash_algo;
@@ -686,12 +678,19 @@ static void process_buffer_measurement(const void *buf, int size,
*/
void ima_kexec_cmdline(const void *buf, int size)
{
+ int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+ struct ima_template_desc *template_desc = NULL;
+ int action;
u32 secid;

if (buf && size != 0) {
security_task_getsecid(current, &secid);
- process_buffer_measurement(buf, size, "kexec-cmdline",
- current_cred(), secid);
+ action = ima_get_action(NULL, current_cred(), secid, 0,
+ KEXEC_CMDLINE, &pcr, &template_desc);
+ if (!(action & IMA_MEASURE))
+ return;
+ process_buffer_measurement(buf, size, "kexec-cmdline", pcr,
+ template_desc);
}
}

--
2.20.1