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Diffstat (limited to 'security/integrity/ima/ima_policy.c')
-rw-r--r--security/integrity/ima/ima_policy.c195
1 files changed, 148 insertions, 47 deletions
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index c84df05180cb..c7dacd2eab7a 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -24,22 +24,29 @@
#define IMA_MASK 0x0002
#define IMA_FSMAGIC 0x0004
#define IMA_UID 0x0008
+#define IMA_FOWNER 0x0010
-enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE };
+#define UNKNOWN 0
+#define MEASURE 0x0001 /* same as IMA_MEASURE */
+#define DONT_MEASURE 0x0002
+#define APPRAISE 0x0004 /* same as IMA_APPRAISE */
+#define DONT_APPRAISE 0x0008
+#define AUDIT 0x0040
#define MAX_LSM_RULES 6
enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
};
-struct ima_measure_rule_entry {
+struct ima_rule_entry {
struct list_head list;
- enum ima_action action;
+ int action;
unsigned int flags;
enum ima_hooks func;
int mask;
unsigned long fsmagic;
kuid_t uid;
+ kuid_t fowner;
struct {
void *rule; /* LSM file metadata specific */
int type; /* audit type */
@@ -48,7 +55,7 @@ struct ima_measure_rule_entry {
/*
* Without LSM specific knowledge, the default policy can only be
- * written in terms of .action, .func, .mask, .fsmagic, and .uid
+ * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
*/
/*
@@ -57,7 +64,7 @@ struct ima_measure_rule_entry {
* normal users can easily run the machine out of memory simply building
* and running executables.
*/
-static struct ima_measure_rule_entry default_rules[] = {
+static struct ima_rule_entry default_rules[] = {
{.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
@@ -75,19 +82,41 @@ static struct ima_measure_rule_entry default_rules[] = {
.flags = IMA_FUNC | IMA_MASK | IMA_UID},
};
-static LIST_HEAD(measure_default_rules);
-static LIST_HEAD(measure_policy_rules);
-static struct list_head *ima_measure;
+static struct ima_rule_entry default_appraise_rules[] = {
+ {.action = DONT_APPRAISE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = RAMFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = DEVPTS_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = BINFMTFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = DONT_APPRAISE,.fsmagic = CGROUP_SUPER_MAGIC,.flags = IMA_FSMAGIC},
+ {.action = APPRAISE,.fowner = GLOBAL_ROOT_UID,.flags = IMA_FOWNER},
+};
+
+static LIST_HEAD(ima_default_rules);
+static LIST_HEAD(ima_policy_rules);
+static struct list_head *ima_rules;
-static DEFINE_MUTEX(ima_measure_mutex);
+static DEFINE_MUTEX(ima_rules_mutex);
static bool ima_use_tcb __initdata;
-static int __init default_policy_setup(char *str)
+static int __init default_measure_policy_setup(char *str)
{
ima_use_tcb = 1;
return 1;
}
-__setup("ima_tcb", default_policy_setup);
+__setup("ima_tcb", default_measure_policy_setup);
+
+static bool ima_use_appraise_tcb __initdata;
+static int __init default_appraise_policy_setup(char *str)
+{
+ ima_use_appraise_tcb = 1;
+ return 1;
+}
+__setup("ima_appraise_tcb", default_appraise_policy_setup);
/**
* ima_match_rules - determine whether an inode matches the measure rule.
@@ -98,7 +127,7 @@ __setup("ima_tcb", default_policy_setup);
*
* Returns true on rule match, false on failure.
*/
-static bool ima_match_rules(struct ima_measure_rule_entry *rule,
+static bool ima_match_rules(struct ima_rule_entry *rule,
struct inode *inode, enum ima_hooks func, int mask)
{
struct task_struct *tsk = current;
@@ -114,6 +143,8 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule,
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))
+ return false;
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
u32 osid, sid;
@@ -163,39 +194,61 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule,
* as elements in the list are never deleted, nor does the list
* change.)
*/
-int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
+int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
+ int flags)
{
- struct ima_measure_rule_entry *entry;
+ struct ima_rule_entry *entry;
+ int action = 0, actmask = flags | (flags << 1);
+
+ list_for_each_entry(entry, ima_rules, list) {
+
+ if (!(entry->action & actmask))
+ continue;
+
+ if (!ima_match_rules(entry, inode, func, mask))
+ continue;
- list_for_each_entry(entry, ima_measure, list) {
- bool rc;
+ action |= entry->action & IMA_DO_MASK;
+ if (entry->action & IMA_DO_MASK)
+ actmask &= ~(entry->action | entry->action << 1);
+ else
+ actmask &= ~(entry->action | entry->action >> 1);
- rc = ima_match_rules(entry, inode, func, mask);
- if (rc)
- return entry->action;
+ if (!actmask)
+ break;
}
- return 0;
+
+ return action;
}
/**
* ima_init_policy - initialize the default measure rules.
*
- * ima_measure points to either the measure_default_rules or the
- * the new measure_policy_rules.
+ * ima_rules points to either the ima_default_rules or the
+ * the new ima_policy_rules.
*/
void __init ima_init_policy(void)
{
- int i, entries;
+ int i, measure_entries, appraise_entries;
/* if !ima_use_tcb set entries = 0 so we load NO default rules */
- if (ima_use_tcb)
- entries = ARRAY_SIZE(default_rules);
- else
- entries = 0;
-
- for (i = 0; i < entries; i++)
- list_add_tail(&default_rules[i].list, &measure_default_rules);
- ima_measure = &measure_default_rules;
+ measure_entries = ima_use_tcb ? ARRAY_SIZE(default_rules) : 0;
+ appraise_entries = ima_use_appraise_tcb ?
+ ARRAY_SIZE(default_appraise_rules) : 0;
+
+ for (i = 0; i < measure_entries + appraise_entries; i++) {
+ if (i < measure_entries)
+ list_add_tail(&default_rules[i].list,
+ &ima_default_rules);
+ else {
+ int j = i - measure_entries;
+
+ list_add_tail(&default_appraise_rules[j].list,
+ &ima_default_rules);
+ }
+ }
+
+ ima_rules = &ima_default_rules;
}
/**
@@ -212,8 +265,8 @@ void ima_update_policy(void)
int result = 1;
int audit_info = 0;
- if (ima_measure == &measure_default_rules) {
- ima_measure = &measure_policy_rules;
+ if (ima_rules == &ima_default_rules) {
+ ima_rules = &ima_policy_rules;
cause = "complete";
result = 0;
}
@@ -224,14 +277,19 @@ void ima_update_policy(void)
enum {
Opt_err = -1,
Opt_measure = 1, Opt_dont_measure,
+ Opt_appraise, Opt_dont_appraise,
+ 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_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner
};
static match_table_t policy_tokens = {
{Opt_measure, "measure"},
{Opt_dont_measure, "dont_measure"},
+ {Opt_appraise, "appraise"},
+ {Opt_dont_appraise, "dont_appraise"},
+ {Opt_audit, "audit"},
{Opt_obj_user, "obj_user=%s"},
{Opt_obj_role, "obj_role=%s"},
{Opt_obj_type, "obj_type=%s"},
@@ -242,10 +300,11 @@ static match_table_t policy_tokens = {
{Opt_mask, "mask=%s"},
{Opt_fsmagic, "fsmagic=%s"},
{Opt_uid, "uid=%s"},
+ {Opt_fowner, "fowner=%s"},
{Opt_err, NULL}
};
-static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry,
+static int ima_lsm_rule_init(struct ima_rule_entry *entry,
char *args, int lsm_rule, int audit_type)
{
int result;
@@ -269,7 +328,7 @@ static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
audit_log_format(ab, " ");
}
-static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
+static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
{
struct audit_buffer *ab;
char *p;
@@ -278,6 +337,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
entry->uid = INVALID_UID;
+ entry->fowner = INVALID_UID;
entry->action = UNKNOWN;
while ((p = strsep(&rule, " \t")) != NULL) {
substring_t args[MAX_OPT_ARGS];
@@ -306,11 +366,35 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
entry->action = DONT_MEASURE;
break;
+ case Opt_appraise:
+ ima_log_string(ab, "action", "appraise");
+
+ if (entry->action != UNKNOWN)
+ result = -EINVAL;
+
+ entry->action = APPRAISE;
+ break;
+ case Opt_dont_appraise:
+ ima_log_string(ab, "action", "dont_appraise");
+
+ if (entry->action != UNKNOWN)
+ result = -EINVAL;
+
+ entry->action = DONT_APPRAISE;
+ break;
+ case Opt_audit:
+ ima_log_string(ab, "action", "audit");
+
+ if (entry->action != UNKNOWN)
+ result = -EINVAL;
+
+ entry->action = AUDIT;
+ break;
case Opt_func:
ima_log_string(ab, "func", args[0].from);
if (entry->func)
- result = -EINVAL;
+ result = -EINVAL;
if (strcmp(args[0].from, "FILE_CHECK") == 0)
entry->func = FILE_CHECK;
@@ -375,6 +459,23 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
entry->flags |= IMA_UID;
}
break;
+ case Opt_fowner:
+ ima_log_string(ab, "fowner", args[0].from);
+
+ if (uid_valid(entry->fowner)) {
+ result = -EINVAL;
+ break;
+ }
+
+ result = strict_strtoul(args[0].from, 10, &lnum);
+ if (!result) {
+ entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
+ if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
+ result = -EINVAL;
+ else
+ entry->flags |= IMA_FOWNER;
+ }
+ break;
case Opt_obj_user:
ima_log_string(ab, "obj_user", args[0].from);
result = ima_lsm_rule_init(entry, args[0].from,
@@ -426,7 +527,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
}
/**
- * ima_parse_add_rule - add a rule to measure_policy_rules
+ * ima_parse_add_rule - add a rule to ima_policy_rules
* @rule - ima measurement policy rule
*
* Uses a mutex to protect the policy list from multiple concurrent writers.
@@ -436,12 +537,12 @@ ssize_t ima_parse_add_rule(char *rule)
{
const char *op = "update_policy";
char *p;
- struct ima_measure_rule_entry *entry;
+ struct ima_rule_entry *entry;
ssize_t result, len;
int audit_info = 0;
/* Prevent installed policy from changing */
- if (ima_measure != &measure_default_rules) {
+ if (ima_rules != &ima_default_rules) {
integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
NULL, op, "already exists",
-EACCES, audit_info);
@@ -474,9 +575,9 @@ ssize_t ima_parse_add_rule(char *rule)
return result;
}
- mutex_lock(&ima_measure_mutex);
- list_add_tail(&entry->list, &measure_policy_rules);
- mutex_unlock(&ima_measure_mutex);
+ mutex_lock(&ima_rules_mutex);
+ list_add_tail(&entry->list, &ima_policy_rules);
+ mutex_unlock(&ima_rules_mutex);
return len;
}
@@ -484,12 +585,12 @@ ssize_t ima_parse_add_rule(char *rule)
/* ima_delete_rules called to cleanup invalid policy */
void ima_delete_rules(void)
{
- struct ima_measure_rule_entry *entry, *tmp;
+ struct ima_rule_entry *entry, *tmp;
- mutex_lock(&ima_measure_mutex);
- list_for_each_entry_safe(entry, tmp, &measure_policy_rules, list) {
+ mutex_lock(&ima_rules_mutex);
+ list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) {
list_del(&entry->list);
kfree(entry);
}
- mutex_unlock(&ima_measure_mutex);
+ mutex_unlock(&ima_rules_mutex);
}