Hi Casey,
On Fri, 2020-11-20 at 12:14 -0800, Casey Schaufler wrote:
diff --git a/security/security.c b/security/security.c
index 5da8b3643680..d01363cb0082 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2510,7 +2526,24 @@ int security_key_getsecurity(struct key *key, char **_buffer)
int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
{
- return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule);
+ struct security_hook_list *hp;
+ bool one_is_good = false;
+ int rc = 0;
+ int trc;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >=
lsm_slot))
+ continue;
+ trc = hp->hook.audit_rule_init(field, op, rulestr,
+ &lsmrule[hp->lsmid->slot]);
+ if (trc == 0)
+ one_is_good = true;
+ else
+ rc = trc;
+ }
+ if (one_is_good)
+ return 0;
+ return rc;
}
So the same string may be defined by multiple LSMs.
int security_audit_rule_known(struct audit_krule *krule)
@@ -2518,14 +2551,31 @@ int security_audit_rule_known(struct audit_krule *krule)
return call_int_hook(audit_rule_known, 0, krule);
}
-void security_audit_rule_free(void *lsmrule)
+void security_audit_rule_free(void **lsmrule)
{
- call_void_hook(audit_rule_free, lsmrule);
+ struct security_hook_list *hp;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_free, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >=
lsm_slot))
+ continue;
+ hp->hook.audit_rule_free(lsmrule[hp->lsmid->slot]);
+ }
}
If one LSM frees the string, then the string is deleted from all LSMs.
I don't understand how this safe.
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void
*lsmrule)
+int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule)
{
- return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
+ struct security_hook_list *hp;
+ int rc;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >=
lsm_slot))
+ continue;
+ rc = hp->hook.audit_rule_match(secid, field, op,
+ &lsmrule[hp->lsmid->slot]);
+ if (rc)
+ return rc;
Suppose that there is an IMA dont_measure or dont_appraise rule, if one
LSM matches, then this returns true, causing any measurement or
integrity verification to be skipped.
Sample policy rules:
dont_measure obj_type=foo_log
dont_appraise obj_type=foo_log
Are there any plans to prevent label collisions or at least notify of a
label collision?
Mimi
+ }
+ return 0;
}
#endif /* CONFIG_AUDIT */