#include <linux/magic.h>
#include <linux/parser.h>
#include <linux/slab.h>
+#include <linux/genhd.h>
#include "ima.h"
#define IMA_FSMAGIC 0x0004
#define IMA_UID 0x0008
#define IMA_FOWNER 0x0010
+#define IMA_FSUUID 0x0020
#define UNKNOWN 0
#define MEASURE 0x0001 /* same as IMA_MEASURE */
enum ima_hooks func;
int mask;
unsigned long fsmagic;
+ u8 fsuuid[16];
kuid_t uid;
kuid_t fowner;
struct {
void *rule; /* LSM file metadata specific */
+ void *args_p; /* audit value */
int type; /* audit type */
} lsm[MAX_LSM_RULES];
};
{.action = DONT_MEASURE,.fsmagic = BINFMTFS_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
- {.action = MEASURE,.func = FILE_MMAP,.mask = MAY_EXEC,
+ {.action = MEASURE,.func = MMAP_CHECK,.mask = MAY_EXEC,
.flags = IMA_FUNC | IMA_MASK},
{.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC,
.flags = IMA_FUNC | IMA_MASK},
}
__setup("ima_appraise_tcb", default_appraise_policy_setup);
+/*
+ * Although the IMA policy does not change, the LSM policy can be
+ * reloaded, leaving the IMA LSM based rules referring to the old,
+ * stale LSM policy.
+ *
+ * Update the IMA LSM based rules to reflect the reloaded LSM policy.
+ * We assume the rules still exist; and BUG_ON() if they don't.
+ */
+static void ima_lsm_update_rules(void)
+{
+ struct ima_rule_entry *entry, *tmp;
+ int result;
+ int i;
+
+ mutex_lock(&ima_rules_mutex);
+ list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) {
+ for (i = 0; i < MAX_LSM_RULES; i++) {
+ if (!entry->lsm[i].rule)
+ continue;
+ result = security_filter_rule_init(entry->lsm[i].type,
+ Audit_equal,
+ entry->lsm[i].args_p,
+ &entry->lsm[i].rule);
+ BUG_ON(!entry->lsm[i].rule);
+ }
+ }
+ mutex_unlock(&ima_rules_mutex);
+}
+
/**
* ima_match_rules - determine whether an inode matches the measure rule.
* @rule: a pointer to a rule
if ((rule->flags & IMA_FSMAGIC)
&& rule->fsmagic != inode->i_sb->s_magic)
return false;
+ if ((rule->flags & IMA_FSUUID) &&
+ memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
+ return false;
if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid))
return false;
if ((rule->flags & IMA_FOWNER) && !uid_eq(rule->fowner, inode->i_uid))
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
u32 osid, sid;
+ int retried = 0;
if (!rule->lsm[i].rule)
continue;
-
+retry:
switch (i) {
case LSM_OBJ_USER:
case LSM_OBJ_ROLE:
default:
break;
}
+ if ((rc < 0) && (!retried)) {
+ retried = 1;
+ ima_lsm_update_rules();
+ goto retry;
+ }
if (!rc)
return false;
}
return true;
}
+/*
+ * In addition to knowing that we need to appraise the file in general,
+ * we need to differentiate between calling hooks, for hook specific rules.
+ */
+static int get_subaction(struct ima_rule_entry *rule, int func)
+{
+ if (!(rule->flags & IMA_FUNC))
+ return IMA_FILE_APPRAISE;
+
+ switch(func) {
+ case MMAP_CHECK:
+ return IMA_MMAP_APPRAISE;
+ case BPRM_CHECK:
+ return IMA_BPRM_APPRAISE;
+ case MODULE_CHECK:
+ return IMA_MODULE_APPRAISE;
+ case FILE_CHECK:
+ default:
+ return IMA_FILE_APPRAISE;
+ }
+}
+
/**
* ima_match_policy - decision based on LSM and other conditions
* @inode: pointer to an inode for which the policy decision is being made
if (!ima_match_rules(entry, inode, func, mask))
continue;
+ action |= entry->flags & IMA_ACTION_FLAGS;
+
action |= entry->action & IMA_DO_MASK;
+ if (entry->action & IMA_APPRAISE)
+ action |= get_subaction(entry, func);
+
if (entry->action & IMA_DO_MASK)
actmask &= ~(entry->action | entry->action << 1);
else
Opt_audit,
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_fowner
+ Opt_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner,
+ Opt_appraise_type, Opt_fsuuid
};
static match_table_t policy_tokens = {
{Opt_func, "func=%s"},
{Opt_mask, "mask=%s"},
{Opt_fsmagic, "fsmagic=%s"},
+ {Opt_fsuuid, "fsuuid=%s"},
{Opt_uid, "uid=%s"},
{Opt_fowner, "fowner=%s"},
+ {Opt_appraise_type, "appraise_type=%s"},
{Opt_err, NULL}
};
static int ima_lsm_rule_init(struct ima_rule_entry *entry,
- char *args, int lsm_rule, int audit_type)
+ substring_t *args, int lsm_rule, int audit_type)
{
int result;
if (entry->lsm[lsm_rule].rule)
return -EINVAL;
+ entry->lsm[lsm_rule].args_p = match_strdup(args);
+ if (!entry->lsm[lsm_rule].args_p)
+ return -ENOMEM;
+
entry->lsm[lsm_rule].type = audit_type;
result = security_filter_rule_init(entry->lsm[lsm_rule].type,
- Audit_equal, args,
+ Audit_equal,
+ entry->lsm[lsm_rule].args_p,
&entry->lsm[lsm_rule].rule);
- if (!entry->lsm[lsm_rule].rule)
+ if (!entry->lsm[lsm_rule].rule) {
+ kfree(entry->lsm[lsm_rule].args_p);
return -EINVAL;
+ }
+
return result;
}
entry->func = FILE_CHECK;
else if (strcmp(args[0].from, "MODULE_CHECK") == 0)
entry->func = MODULE_CHECK;
- else if (strcmp(args[0].from, "FILE_MMAP") == 0)
- entry->func = FILE_MMAP;
+ else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
+ || (strcmp(args[0].from, "MMAP_CHECK") == 0))
+ entry->func = MMAP_CHECK;
else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
entry->func = BPRM_CHECK;
else
if (!result)
entry->flags |= IMA_FSMAGIC;
break;
+ case Opt_fsuuid:
+ ima_log_string(ab, "fsuuid", args[0].from);
+
+ if (memchr_inv(entry->fsuuid, 0x00,
+ sizeof(entry->fsuuid))) {
+ result = -EINVAL;
+ break;
+ }
+
+ part_pack_uuid(args[0].from, entry->fsuuid);
+ entry->flags |= IMA_FSUUID;
+ result = 0;
+ break;
case Opt_uid:
ima_log_string(ab, "uid", args[0].from);
break;
case Opt_obj_user:
ima_log_string(ab, "obj_user", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
+ result = ima_lsm_rule_init(entry, args,
LSM_OBJ_USER,
AUDIT_OBJ_USER);
break;
case Opt_obj_role:
ima_log_string(ab, "obj_role", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
+ result = ima_lsm_rule_init(entry, args,
LSM_OBJ_ROLE,
AUDIT_OBJ_ROLE);
break;
case Opt_obj_type:
ima_log_string(ab, "obj_type", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
+ result = ima_lsm_rule_init(entry, args,
LSM_OBJ_TYPE,
AUDIT_OBJ_TYPE);
break;
case Opt_subj_user:
ima_log_string(ab, "subj_user", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
+ result = ima_lsm_rule_init(entry, args,
LSM_SUBJ_USER,
AUDIT_SUBJ_USER);
break;
case Opt_subj_role:
ima_log_string(ab, "subj_role", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
+ result = ima_lsm_rule_init(entry, args,
LSM_SUBJ_ROLE,
AUDIT_SUBJ_ROLE);
break;
case Opt_subj_type:
ima_log_string(ab, "subj_type", args[0].from);
- result = ima_lsm_rule_init(entry, args[0].from,
+ result = ima_lsm_rule_init(entry, args,
LSM_SUBJ_TYPE,
AUDIT_SUBJ_TYPE);
break;
+ case Opt_appraise_type:
+ if (entry->action != APPRAISE) {
+ result = -EINVAL;
+ break;
+ }
+
+ ima_log_string(ab, "appraise_type", args[0].from);
+ if ((strcmp(args[0].from, "imasig")) == 0)
+ entry->flags |= IMA_DIGSIG_REQUIRED;
+ else
+ result = -EINVAL;
+ break;
case Opt_err:
ima_log_string(ab, "UNKNOWN", p);
result = -EINVAL;
void ima_delete_rules(void)
{
struct ima_rule_entry *entry, *tmp;
+ int i;
mutex_lock(&ima_rules_mutex);
list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) {
+ for (i = 0; i < MAX_LSM_RULES; i++)
+ kfree(entry->lsm[i].args_p);
+
list_del(&entry->list);
kfree(entry);
}
projects / cascardo / linux.git / blobdiff