diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index f93460156dc..f4c28eeba1b 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -44,6 +44,7 @@ enum smk_inos { SMK_ONLYCAP = 9, /* the only "capable" label */ SMK_LOGGING = 10, /* logging */ SMK_LOAD_SELF = 11, /* task specific rules */ + SMK_ACCESSES = 12, /* access policy */ }; /* @@ -175,6 +176,81 @@ static int smk_set_access(struct smack_rule *srp, struct list_head *rule_list, return found; } +/** + * smk_parse_rule - parse subject, object and access type + * @data: string to be parsed whose size is SMK_LOADLEN + * @rule: parsed entities are stored in here + */ +static int smk_parse_rule(const char *data, struct smack_rule *rule) +{ + 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; + + rule->smk_access = 0; + + switch (data[SMK_LABELLEN + SMK_LABELLEN]) { + case '-': + break; + case 'r': + case 'R': + rule->smk_access |= MAY_READ; + break; + default: + return -1; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) { + case '-': + break; + case 'w': + case 'W': + rule->smk_access |= MAY_WRITE; + break; + default: + return -1; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) { + case '-': + break; + case 'x': + case 'X': + rule->smk_access |= MAY_EXEC; + break; + default: + return -1; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) { + case '-': + break; + case 'a': + case 'A': + rule->smk_access |= MAY_APPEND; + break; + default: + return -1; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 4]) { + case '-': + break; + case 't': + case 'T': + rule->smk_access |= MAY_TRANSMUTE; + break; + default: + return -1; + } + + return 0; +} + /** * smk_write_load_list - write() for any /smack/load * @file: file pointer, not actually used @@ -234,71 +310,9 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf, goto out; } - rule->smk_subject = smk_import(data, 0); - if (rule->smk_subject == NULL) + if (smk_parse_rule(data, rule)) goto out_free_rule; - rule->smk_object = smk_import(data + SMK_LABELLEN, 0); - if (rule->smk_object == NULL) - goto out_free_rule; - - rule->smk_access = 0; - - switch (data[SMK_LABELLEN + SMK_LABELLEN]) { - case '-': - break; - case 'r': - case 'R': - rule->smk_access |= MAY_READ; - break; - default: - goto out_free_rule; - } - - switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) { - case '-': - break; - case 'w': - case 'W': - rule->smk_access |= MAY_WRITE; - break; - default: - goto out_free_rule; - } - - switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) { - case '-': - break; - case 'x': - case 'X': - rule->smk_access |= MAY_EXEC; - break; - default: - goto out_free_rule; - } - - switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) { - case '-': - break; - case 'a': - case 'A': - rule->smk_access |= MAY_APPEND; - break; - default: - goto out_free_rule; - } - - switch (data[SMK_LABELLEN + SMK_LABELLEN + 4]) { - case '-': - break; - case 't': - case 'T': - rule->smk_access |= MAY_TRANSMUTE; - break; - default: - goto out_free_rule; - } - rc = count; /* * smk_set_access returns true if there was already a rule @@ -1425,6 +1439,44 @@ static const struct file_operations smk_load_self_ops = { .write = smk_write_load_self, .release = seq_release, }; + +/** + * smk_write_access - handle access check transaction + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_access(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_rule rule; + char *data; + + 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)) + return -EINVAL; + + data[0] = smk_access(rule.smk_subject, rule.smk_object, + rule.smk_access, NULL) == 0; + + simple_transaction_set(file, 1); + return SMK_LOADLEN; +} + +static const struct file_operations smk_access_ops = { + .write = smk_write_access, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + /** * smk_fill_super - fill the /smackfs superblock * @sb: the empty superblock @@ -1459,6 +1511,8 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent) "logging", &smk_logging_ops, S_IRUGO|S_IWUSR}, [SMK_LOAD_SELF] = { "load-self", &smk_load_self_ops, S_IRUGO|S_IWUGO}, + [SMK_ACCESSES] = { + "access", &smk_access_ops, S_IRUGO|S_IWUSR}, /* last one */ {""} };