IMA: allow reading back the current IMA policy
It is often useful to be able to read back the IMA policy. It is
even more important after introducing CONFIG_IMA_WRITE_POLICY.
This option allows the root user to see the current policy rules.
Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Signed-off-by: Petko Manolov <petkan@mip-labs.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 10a0a9b..2f4e0f5 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -18,6 +18,7 @@
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/genhd.h>
+#include <linux/seq_file.h>
#include "ima.h"
@@ -458,8 +459,8 @@
Opt_obj_user, Opt_obj_role, Opt_obj_type,
Opt_subj_user, Opt_subj_role, Opt_subj_type,
Opt_func, Opt_mask, Opt_fsmagic,
- Opt_uid, Opt_euid, Opt_fowner,
- Opt_appraise_type, Opt_fsuuid, Opt_permit_directio
+ Opt_fsuuid, Opt_uid, Opt_euid, Opt_fowner,
+ Opt_appraise_type, Opt_permit_directio
};
static match_table_t policy_tokens = {
@@ -828,3 +829,205 @@
kfree(entry);
}
}
+
+#ifdef CONFIG_IMA_READ_POLICY
+enum {
+ mask_exec = 0, mask_write, mask_read, mask_append
+};
+
+static char *mask_tokens[] = {
+ "MAY_EXEC",
+ "MAY_WRITE",
+ "MAY_READ",
+ "MAY_APPEND"
+};
+
+enum {
+ func_file = 0, func_mmap, func_bprm,
+ func_module, func_firmware, func_post
+};
+
+static char *func_tokens[] = {
+ "FILE_CHECK",
+ "MMAP_CHECK",
+ "BPRM_CHECK",
+ "MODULE_CHECK",
+ "FIRMWARE_CHECK",
+ "POST_SETATTR"
+};
+
+void *ima_policy_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t l = *pos;
+ struct ima_rule_entry *entry;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(entry, ima_rules, list) {
+ if (!l--) {
+ rcu_read_unlock();
+ return entry;
+ }
+ }
+ rcu_read_unlock();
+ return NULL;
+}
+
+void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct ima_rule_entry *entry = v;
+
+ rcu_read_lock();
+ entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list);
+ rcu_read_unlock();
+ (*pos)++;
+
+ return (&entry->list == ima_rules) ? NULL : entry;
+}
+
+void ima_policy_stop(struct seq_file *m, void *v)
+{
+}
+
+#define pt(token) policy_tokens[token + Opt_err].pattern
+#define mt(token) mask_tokens[token]
+#define ft(token) func_tokens[token]
+
+int ima_policy_show(struct seq_file *m, void *v)
+{
+ struct ima_rule_entry *entry = v;
+ int i = 0;
+ char tbuf[64] = {0,};
+
+ rcu_read_lock();
+
+ if (entry->action & MEASURE)
+ seq_puts(m, pt(Opt_measure));
+ if (entry->action & DONT_MEASURE)
+ seq_puts(m, pt(Opt_dont_measure));
+ if (entry->action & APPRAISE)
+ seq_puts(m, pt(Opt_appraise));
+ if (entry->action & DONT_APPRAISE)
+ seq_puts(m, pt(Opt_dont_appraise));
+ if (entry->action & AUDIT)
+ seq_puts(m, pt(Opt_audit));
+
+ seq_puts(m, " ");
+
+ if (entry->flags & IMA_FUNC) {
+ switch (entry->func) {
+ case FILE_CHECK:
+ seq_printf(m, pt(Opt_func), ft(func_file));
+ break;
+ case MMAP_CHECK:
+ seq_printf(m, pt(Opt_func), ft(func_mmap));
+ break;
+ case BPRM_CHECK:
+ seq_printf(m, pt(Opt_func), ft(func_bprm));
+ break;
+ case MODULE_CHECK:
+ seq_printf(m, pt(Opt_func), ft(func_module));
+ break;
+ case FIRMWARE_CHECK:
+ seq_printf(m, pt(Opt_func), ft(func_firmware));
+ break;
+ case POST_SETATTR:
+ seq_printf(m, pt(Opt_func), ft(func_post));
+ break;
+ default:
+ snprintf(tbuf, sizeof(tbuf), "%d", entry->func);
+ seq_printf(m, pt(Opt_func), tbuf);
+ break;
+ }
+ seq_puts(m, " ");
+ }
+
+ if (entry->flags & IMA_MASK) {
+ if (entry->mask & MAY_EXEC)
+ seq_printf(m, pt(Opt_mask), mt(mask_exec));
+ if (entry->mask & MAY_WRITE)
+ seq_printf(m, pt(Opt_mask), mt(mask_write));
+ if (entry->mask & MAY_READ)
+ seq_printf(m, pt(Opt_mask), mt(mask_read));
+ if (entry->mask & MAY_APPEND)
+ seq_printf(m, pt(Opt_mask), mt(mask_append));
+ seq_puts(m, " ");
+ }
+
+ if (entry->flags & IMA_FSMAGIC) {
+ snprintf(tbuf, sizeof(tbuf), "0x%lx", entry->fsmagic);
+ seq_printf(m, pt(Opt_fsmagic), tbuf);
+ seq_puts(m, " ");
+ }
+
+ if (entry->flags & IMA_FSUUID) {
+ seq_puts(m, "fsuuid=");
+ for (i = 0; i < ARRAY_SIZE(entry->fsuuid); ++i) {
+ switch (i) {
+ case 4:
+ case 6:
+ case 8:
+ case 10:
+ seq_puts(m, "-");
+ }
+ seq_printf(m, "%x", entry->fsuuid[i]);
+ }
+ seq_puts(m, " ");
+ }
+
+ if (entry->flags & IMA_UID) {
+ snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
+ seq_printf(m, pt(Opt_uid), tbuf);
+ seq_puts(m, " ");
+ }
+
+ if (entry->flags & IMA_EUID) {
+ snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
+ seq_printf(m, pt(Opt_euid), tbuf);
+ seq_puts(m, " ");
+ }
+
+ if (entry->flags & IMA_FOWNER) {
+ snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner));
+ seq_printf(m, pt(Opt_fowner), tbuf);
+ seq_puts(m, " ");
+ }
+
+ for (i = 0; i < MAX_LSM_RULES; i++) {
+ if (entry->lsm[i].rule) {
+ switch (i) {
+ case LSM_OBJ_USER:
+ seq_printf(m, pt(Opt_obj_user),
+ (char *)entry->lsm[i].args_p);
+ break;
+ case LSM_OBJ_ROLE:
+ seq_printf(m, pt(Opt_obj_role),
+ (char *)entry->lsm[i].args_p);
+ break;
+ case LSM_OBJ_TYPE:
+ seq_printf(m, pt(Opt_obj_type),
+ (char *)entry->lsm[i].args_p);
+ break;
+ case LSM_SUBJ_USER:
+ seq_printf(m, pt(Opt_subj_user),
+ (char *)entry->lsm[i].args_p);
+ break;
+ case LSM_SUBJ_ROLE:
+ seq_printf(m, pt(Opt_subj_role),
+ (char *)entry->lsm[i].args_p);
+ break;
+ case LSM_SUBJ_TYPE:
+ seq_printf(m, pt(Opt_subj_type),
+ (char *)entry->lsm[i].args_p);
+ break;
+ }
+ }
+ }
+ if (entry->flags & IMA_DIGSIG_REQUIRED)
+ seq_puts(m, "appraise_type=imasig ");
+ if (entry->flags & IMA_PERMIT_DIRECTIO)
+ seq_puts(m, "permit_directio ");
+ rcu_read_unlock();
+ seq_puts(m, "\n");
+ return 0;
+}
+#endif /* CONFIG_IMA_READ_POLICY */