[Cc'ing Prakhar Srivastava]
On Mon, 2019-10-07 at 21:14 -0400, Nayna Jain wrote:
> 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.
The purpose of this patch is to make process_buffer_measurement() more
generic. The patch description should simply say,
process_buffer_measurement() is limited to measuring the kexec boot
command line. This patch makes process_buffer_measurement() more
generic, allowing it to measure other types of buffer data (eg.
blacklisted binary hashes).
Mimi
>
> Signed-off-by: Nayna Jain <na...@linux.ibm.com>
> ---
> 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);
> }
> }
>
