Signed-off-by: Lakshmi Ramasubramanian <nra...@linux.microsoft.com>
Suggested-by: Stephen Smalley <stephen.smalley.w...@gmail.com>
Suggested-by: Paul Moore <p...@paul-moore.com>
---
security/selinux/ima.c | 87 ++++++++++++++++++++++++++++++++--
security/selinux/include/ima.h | 6 +++
security/selinux/selinuxfs.c | 6 +++
security/selinux/ss/services.c | 2 +-
4 files changed, 96 insertions(+), 5 deletions(-)
diff --git a/security/selinux/ima.c b/security/selinux/ima.c
index 03715893ff97..34d421861bfc 100644
--- a/security/selinux/ima.c
+++ b/security/selinux/ima.c
@@ -13,18 +13,83 @@
#include "ima.h"
/*
- * selinux_ima_measure_state - Measure hash of the SELinux policy
+ * selinux_ima_collect_state - Read selinux configuration settings
*
- * @state: selinux state struct
+ * @state: selinux_state
*
- * NOTE: This function must be called with policy_mutex held.
+ * On success returns the configuration settings string.
+ * On error, returns NULL.
*/
-void selinux_ima_measure_state(struct selinux_state *state)
+static char *selinux_ima_collect_state(struct selinux_state *state)
{
+ const char *on = "=1;", *off = "=0;";
+ char *buf;
+ int buf_len, len, i, rc;
+
+ buf_len = strlen("initialized=0;enforcing=0;checkreqprot=0;") + 1;
+
+ len = strlen(on);
+ for (i = 0; i < __POLICYDB_CAPABILITY_MAX; i++)
+ buf_len += strlen(selinux_policycap_names[i]) + len;
+
+ buf = kzalloc(buf_len, GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ rc = strscpy(buf, "initialized", buf_len);
+ WARN_ON(rc < 0);
+
+ rc = strlcat(buf, selinux_initialized(state) ? on : off, buf_len);
+ WARN_ON(rc >= buf_len);
+
+ rc = strlcat(buf, "enforcing", buf_len);
+ WARN_ON(rc >= buf_len);
+
+ rc = strlcat(buf, enforcing_enabled(state) ? on : off, buf_len);
+ WARN_ON(rc >= buf_len);
+
+ rc = strlcat(buf, "checkreqprot", buf_len);
+ WARN_ON(rc >= buf_len);
+
+ rc = strlcat(buf, checkreqprot_get(state) ? on : off, buf_len);
+ WARN_ON(rc >= buf_len);
+
+ for (i = 0; i < __POLICYDB_CAPABILITY_MAX; i++) {
+ rc = strlcat(buf, selinux_policycap_names[i], buf_len);
+ WARN_ON(rc >= buf_len);
+
+ rc = strlcat(buf, state->policycap[i] ? on : off, buf_len);
+ WARN_ON(rc >= buf_len);
+ }
+
+ return buf;
+}
+
+/*
+ * selinux_ima_measure_state_locked - Measure SELinux state and hash of policy
+ *
+ * @state: selinux state struct
+ */
+void selinux_ima_measure_state_locked(struct selinux_state *state)
+{
+ char *state_str = NULL;
void *policy = NULL;
size_t policy_len;
int rc = 0;
+ WARN_ON(!mutex_is_locked(&state->policy_mutex));
+
+ state_str = selinux_ima_collect_state(state);
+ if (!state_str) {
+ pr_err("SELinux: %s: failed to read state.\n", __func__);
+ return;
+ }
+
+ ima_measure_critical_data("selinux", "selinux-state",
+ state_str, strlen(state_str), false);
+
+ kfree(state_str);
+
/*
* Measure SELinux policy only after initialization is completed.
*/
@@ -42,3 +107,17 @@ void selinux_ima_measure_state(struct selinux_state *state)
vfree(policy);
}
+
+/*
+ * selinux_ima_measure_state - Measure SELinux state and hash of policy
+ *
+ * @state: selinux state struct
+ */
+void selinux_ima_measure_state(struct selinux_state *state)
+{
+ WARN_ON(mutex_is_locked(&state->policy_mutex));
+
+ mutex_lock(&state->policy_mutex);
+ selinux_ima_measure_state_locked(state);
+ mutex_unlock(&state->policy_mutex);
+}
diff --git a/security/selinux/include/ima.h b/security/selinux/include/ima.h
index d69c36611423..75ca92b4a462 100644
--- a/security/selinux/include/ima.h
+++ b/security/selinux/include/ima.h
@@ -15,10 +15,16 @@
#ifdef CONFIG_IMA
extern void selinux_ima_measure_state(struct selinux_state *selinux_state);
+extern void selinux_ima_measure_state_locked(
+ struct selinux_state *selinux_state);
#else
static inline void selinux_ima_measure_state(struct selinux_state
*selinux_state)
{
}
+static inline void selinux_ima_measure_state_locked(
+ struct selinux_state *selinux_state)
+{
+}
#endif
#endif /* _SELINUX_IMA_H_ */
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 4bde570d56a2..26ec58593ba1 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -41,6 +41,7 @@
#include "security.h"
#include "objsec.h"
#include "conditional.h"
+#include "ima.h"
enum sel_inos {
SEL_ROOT_INO = 2,
@@ -182,6 +183,8 @@ static ssize_t sel_write_enforce(struct file *file, const
char __user *buf,
selinux_status_update_setenforce(state, new_value);
if (!new_value)
call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
+
+ selinux_ima_measure_state(state);
}
length = count;
out:
@@ -762,6 +765,9 @@ static ssize_t sel_write_checkreqprot(struct file *file,
const char __user *buf,
checkreqprot_set(fsi->state, (new_value ? 1 : 0));
length = count;
+
+ selinux_ima_measure_state(fsi->state);
+
out:
kfree(page);
return length;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 2106b5d383e7..cb2866489363 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2179,7 +2179,7 @@ static void selinux_notify_policy_change(struct
selinux_state *state,
selinux_status_update_policyload(state, seqno);
selinux_netlbl_cache_invalidate();
selinux_xfrm_notify_policyload();
- selinux_ima_measure_state(state);
+ selinux_ima_measure_state_locked(state);
}
void selinux_policy_commit(struct selinux_state *state,