Commit 0e94ae17 authored by Jarkko Sakkinen's avatar Jarkko Sakkinen Committed by Casey Schaufler

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: default avatarJarkko Sakkinen <jarkko.j.sakkinen@gmail.com>
Signed-off-by: default avatarCasey Schaufler <cschaufler@cschaufler-intel.(none)>
parent d86b2b61
......@@ -208,6 +208,7 @@ int smk_curacc(char *, u32, struct smk_audit_info *);
int smack_to_cipso(const char *, struct smack_cipso *);
char *smack_from_cipso(u32, char *);
char *smack_from_secid(const u32);
void smk_parse_smack(const char *string, int len, char *smack);
char *smk_import(const char *, int);
struct smack_known *smk_import_entry(const char *, int);
struct smack_known *smk_find_entry(const char *);
......
......@@ -353,17 +353,13 @@ struct smack_known *smk_find_entry(const char *string)
}
/**
* smk_import_entry - import a label, return the list entry
* @string: a text string that might be a Smack label
* smk_parse_smack - parse smack label from a text string
* @string: a text string that might contain a Smack label
* @len: the maximum size, or zero if it is NULL terminated.
*
* Returns a pointer to the entry in the label list that
* matches the passed string, adding it if necessary.
* @smack: parsed smack label, or NULL if parse error
*/
struct smack_known *smk_import_entry(const char *string, int len)
void smk_parse_smack(const char *string, int len, char *smack)
{
struct smack_known *skp;
char smack[SMK_LABELLEN];
int found;
int i;
......@@ -381,7 +377,22 @@ struct smack_known *smk_import_entry(const char *string, int len)
} else
smack[i] = string[i];
}
}
/**
* smk_import_entry - import a label, return the list entry
* @string: a text string that might be a Smack label
* @len: the maximum size, or zero if it is NULL terminated.
*
* Returns a pointer to the entry in the label list that
* matches the passed string, adding it if necessary.
*/
struct smack_known *smk_import_entry(const char *string, int len)
{
struct smack_known *skp;
char smack[SMK_LABELLEN];
smk_parse_smack(string, len, smack);
if (smack[0] == '\0')
return NULL;
......
......@@ -191,19 +191,37 @@ static int smk_set_access(struct smack_rule *srp, struct list_head *rule_list,
}
/**
* 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 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf,
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 @@ static ssize_t smk_write_access(struct file *file, const char __user *buf,
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 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
[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 */
{""}
};
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment