lkml.org 
[lkml]   [2020]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 3/5] LSM: Add security_measure_data in lsm_info struct
Date
The security modules that require their data to be measured using
the IMA subsystem need to define a function that the LSM can call
to trigger the measurement.

Add a function pointer field namely security_measure_data in lsm_info
structure. Update LSM to call this security module function, if defined,
to measure the security module's data using the IMA subsystem.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
include/linux/lsm_hooks.h | 3 +++
security/security.c | 48 ++++++++++++++++++++++++++++++++++++++-
2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 95b7c1d32062..56f0e524838c 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1591,6 +1591,9 @@ struct lsm_info {
int *enabled; /* Optional: controlled by CONFIG_LSM */
int (*init)(void); /* Required. */
struct lsm_blob_sizes *blobs; /* Optional: for blob sharing. */
+ int (*security_measure_data)(void); /* Optional: for measuring
+ * security module data.
+ */
};

extern struct lsm_info __start_lsm_info[], __end_lsm_info[];
diff --git a/security/security.c b/security/security.c
index 70a7ad357bc6..1afa2aebc3ac 100644
--- a/security/security.c
+++ b/security/security.c
@@ -86,6 +86,9 @@ static __initconst const char * const builtin_lsm_order = CONFIG_LSM;
static __initdata struct lsm_info **ordered_lsms;
static __initdata struct lsm_info *exclusive;

+static struct lsm_info *security_state_lsms;
+static int security_state_lsms_count;
+
static __initdata bool debug;
#define init_debug(...) \
do { \
@@ -235,6 +238,45 @@ static void __init initialize_lsm(struct lsm_info *lsm)
}
}

+static int measure_security_state(struct lsm_info *lsm)
+{
+ if (!lsm->security_measure_data)
+ return 0;
+
+ return lsm->security_measure_data();
+}
+
+static void __init initialize_security_state_lsms(void)
+{
+ struct lsm_info **lsm;
+ int count = 0;
+ int inx;
+
+ for (lsm = ordered_lsms; *lsm; lsm++) {
+ if ((*lsm)->security_measure_data)
+ count++;
+ }
+
+ if (count == 0)
+ return;
+
+ security_state_lsms = kcalloc(count, sizeof(struct lsm_info),
+ GFP_KERNEL);
+ if (!security_state_lsms)
+ return;
+
+ inx = 0;
+ for (lsm = ordered_lsms; *lsm; lsm++) {
+ if ((*lsm)->security_measure_data) {
+ security_state_lsms[inx].security_measure_data =
+ (*lsm)->security_measure_data;
+ inx++;
+ }
+ }
+
+ security_state_lsms_count = count;
+}
+
/* Populate ordered LSMs list from comma-separated LSM name list. */
static void __init ordered_lsm_parse(const char *order, const char *origin)
{
@@ -352,8 +394,12 @@ static void __init ordered_lsm_init(void)

lsm_early_cred((struct cred *) current->cred);
lsm_early_task(current);
- for (lsm = ordered_lsms; *lsm; lsm++)
+ for (lsm = ordered_lsms; *lsm; lsm++) {
initialize_lsm(*lsm);
+ measure_security_state(*lsm);
+ }
+
+ initialize_security_state_lsms();

kfree(ordered_lsms);
}
--
2.27.0
\
 
 \ /
  Last update: 2020-07-16 19:45    [W:0.052 / U:1.704 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site