diff options
Diffstat (limited to 'security/integrity/ima/ima_policy.c')
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 48 |
1 files changed, 34 insertions, 14 deletions
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index b5291ad5ef56..e1278399b345 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -45,24 +45,30 @@ struct ima_measure_rule_entry { } lsm[MAX_LSM_RULES]; }; -/* Without LSM specific knowledge, the default policy can only be +/* + * Without LSM specific knowledge, the default policy can only be * written in terms of .action, .func, .mask, .fsmagic, and .uid */ + +/* + * The minimum rule set to allow for full TCB coverage. Measures all files + * opened or mmap for exec and everything read by root. Dangerous because + * normal users can easily run the machine out of memory simply building + * and running executables. + */ static struct ima_measure_rule_entry default_rules[] = { - {.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC, - .flags = IMA_FSMAGIC}, + {.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}, {.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC}, - {.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC, - .flags = IMA_FSMAGIC}, - {.action = DONT_MEASURE,.fsmagic = 0xF97CFF8C,.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, .flags = IMA_FUNC | IMA_MASK}, {.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC, .flags = IMA_FUNC | IMA_MASK}, {.action = MEASURE,.func = PATH_CHECK,.mask = MAY_READ,.uid = 0, - .flags = IMA_FUNC | IMA_MASK | IMA_UID} + .flags = IMA_FUNC | IMA_MASK | IMA_UID}, }; static LIST_HEAD(measure_default_rules); @@ -71,6 +77,14 @@ static struct list_head *ima_measure; static DEFINE_MUTEX(ima_measure_mutex); +static bool ima_use_tcb __initdata; +static int __init default_policy_setup(char *str) +{ + ima_use_tcb = 1; + return 1; +} +__setup("ima_tcb", default_policy_setup); + /** * ima_match_rules - determine whether an inode matches the measure rule. * @rule: a pointer to a rule @@ -96,7 +110,7 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule, if ((rule->flags & IMA_UID) && rule->uid != tsk->cred->uid) return false; for (i = 0; i < MAX_LSM_RULES; i++) { - int rc; + int rc = 0; u32 osid, sid; if (!rule->lsm[i].rule) @@ -109,7 +123,7 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule, security_inode_getsecid(inode, &osid); rc = security_filter_rule_match(osid, rule->lsm[i].type, - AUDIT_EQUAL, + Audit_equal, rule->lsm[i].rule, NULL); break; @@ -119,7 +133,7 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule, security_task_getsecid(tsk, &sid); rc = security_filter_rule_match(sid, rule->lsm[i].type, - AUDIT_EQUAL, + Audit_equal, rule->lsm[i].rule, NULL); default: @@ -164,11 +178,17 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask) * ima_measure points to either the measure_default_rules or the * the new measure_policy_rules. */ -void ima_init_policy(void) +void __init ima_init_policy(void) { - int i; + int i, 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 < ARRAY_SIZE(default_rules); i++) + for (i = 0; i < entries; i++) list_add_tail(&default_rules[i].list, &measure_default_rules); ima_measure = &measure_default_rules; } @@ -227,7 +247,7 @@ static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry, entry->lsm[lsm_rule].type = audit_type; result = security_filter_rule_init(entry->lsm[lsm_rule].type, - AUDIT_EQUAL, args, + Audit_equal, args, &entry->lsm[lsm_rule].rule); return result; } |