Smack: allow to access /smack/access as normal user
Allow query access as a normal user removing the need
for CAP_MAC_ADMIN. Give RW access to /smack/access
for UGO. Do not import smack labels in access check.
Signed-off-by: Jarkko Sakkinen <jarkko.j.sakkinen@gmail.com>
Signed-off-by: Casey Schaufler <cschaufler@cschaufler-intel.(none)>
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 381eecf..6aceef5 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -191,19 +191,37 @@
}
/**
- * smk_parse_rule - parse subject, object and access type
+ * smk_parse_rule - parse Smack rule from load string
* @data: string to be parsed whose size is SMK_LOADLEN
- * @rule: parsed entities are stored in here
+ * @rule: Smack rule
+ * @import: if non-zero, import labels
*/
-static int smk_parse_rule(const char *data, struct smack_rule *rule)
+static int smk_parse_rule(const char *data, struct smack_rule *rule, int import)
{
- rule->smk_subject = smk_import(data, 0);
- if (rule->smk_subject == NULL)
- return -1;
+ char smack[SMK_LABELLEN];
+ struct smack_known *skp;
- rule->smk_object = smk_import(data + SMK_LABELLEN, 0);
- if (rule->smk_object == NULL)
- return -1;
+ if (import) {
+ rule->smk_subject = smk_import(data, 0);
+ if (rule->smk_subject == NULL)
+ return -1;
+
+ rule->smk_object = smk_import(data + SMK_LABELLEN, 0);
+ if (rule->smk_object == NULL)
+ return -1;
+ } else {
+ smk_parse_smack(data, 0, smack);
+ skp = smk_find_entry(smack);
+ if (skp == NULL)
+ return -1;
+ rule->smk_subject = skp->smk_known;
+
+ smk_parse_smack(data + SMK_LABELLEN, 0, smack);
+ skp = smk_find_entry(smack);
+ if (skp == NULL)
+ return -1;
+ rule->smk_object = skp->smk_known;
+ }
rule->smk_access = 0;
@@ -327,7 +345,7 @@
goto out;
}
- if (smk_parse_rule(data, rule))
+ if (smk_parse_rule(data, rule, 1))
goto out_free_rule;
if (rule_list == NULL) {
@@ -1499,14 +1517,11 @@
char *data;
int res;
- if (!capable(CAP_MAC_ADMIN))
- return -EPERM;
-
data = simple_transaction_get(file, buf, count);
if (IS_ERR(data))
return PTR_ERR(data);
- if (count < SMK_LOADLEN || smk_parse_rule(data, &rule))
+ if (count < SMK_LOADLEN || smk_parse_rule(data, &rule, 0))
return -EINVAL;
res = smk_access(rule.smk_subject, rule.smk_object, rule.smk_access,
@@ -1560,7 +1575,7 @@
[SMK_LOAD_SELF] = {
"load-self", &smk_load_self_ops, S_IRUGO|S_IWUGO},
[SMK_ACCESSES] = {
- "access", &smk_access_ops, S_IRUGO|S_IWUSR},
+ "access", &smk_access_ops, S_IRUGO|S_IWUGO},
/* last one */
{""}
};