diff options
| -rw-r--r-- | security/smack/smackfs.c | 180 |
1 files changed, 117 insertions, 63 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index f93460156dce..f4c28eeba1b1 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 */ }; /* @@ -176,71 +177,19 @@ static int smk_set_access(struct smack_rule *srp, struct list_head *rule_list, } /** - * smk_write_load_list - write() for any /smack/load - * @file: file pointer, not actually used - * @buf: where to get the data from - * @count: bytes sent - * @ppos: where to start - must be 0 - * @rule_list: the list of rules to write to - * @rule_lock: lock for the rule list - * - * Get one smack access rule from above. - * The format is exactly: - * char subject[SMK_LABELLEN] - * char object[SMK_LABELLEN] - * char access[SMK_ACCESSLEN] - * - * writes must be SMK_LABELLEN+SMK_LABELLEN+SMK_ACCESSLEN bytes. + * 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 ssize_t smk_write_load_list(struct file *file, const char __user *buf, - size_t count, loff_t *ppos, - struct list_head *rule_list, - struct mutex *rule_lock) +static int smk_parse_rule(const char *data, struct smack_rule *rule) { - struct smack_rule *rule; - char *data; - int rc = -EINVAL; - - /* - * No partial writes. - * Enough data must be present. - */ - if (*ppos != 0) - return -EINVAL; - /* - * Minor hack for backward compatibility - */ - if (count < (SMK_OLOADLEN) || count > SMK_LOADLEN) - return -EINVAL; - - data = kzalloc(SMK_LOADLEN, GFP_KERNEL); - if (data == NULL) - return -ENOMEM; - - if (copy_from_user(data, buf, count) != 0) { - rc = -EFAULT; - goto out; - } - - /* - * More on the minor hack for backward compatibility - */ - if (count == (SMK_OLOADLEN)) - data[SMK_OLOADLEN] = '-'; - - rule = kzalloc(sizeof(*rule), GFP_KERNEL); - if (rule == NULL) { - rc = -ENOMEM; - goto out; - } - rule->smk_subject = smk_import(data, 0); if (rule->smk_subject == NULL) - goto out_free_rule; + return -1; rule->smk_object = smk_import(data + SMK_LABELLEN, 0); if (rule->smk_object == NULL) - goto out_free_rule; + return -1; rule->smk_access = 0; @@ -252,7 +201,7 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf, rule->smk_access |= MAY_READ; break; default: - goto out_free_rule; + return -1; } switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) { @@ -263,7 +212,7 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf, rule->smk_access |= MAY_WRITE; break; default: - goto out_free_rule; + return -1; } switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) { @@ -274,7 +223,7 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf, rule->smk_access |= MAY_EXEC; break; default: - goto out_free_rule; + return -1; } switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) { @@ -285,7 +234,7 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf, rule->smk_access |= MAY_APPEND; break; default: - goto out_free_rule; + return -1; } switch (data[SMK_LABELLEN + SMK_LABELLEN + 4]) { @@ -296,9 +245,74 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf, rule->smk_access |= MAY_TRANSMUTE; break; default: - goto out_free_rule; + return -1; } + return 0; +} + +/** + * smk_write_load_list - write() for any /smack/load + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * @rule_list: the list of rules to write to + * @rule_lock: lock for the rule list + * + * Get one smack access rule from above. + * The format is exactly: + * char subject[SMK_LABELLEN] + * char object[SMK_LABELLEN] + * char access[SMK_ACCESSLEN] + * + * writes must be SMK_LABELLEN+SMK_LABELLEN+SMK_ACCESSLEN bytes. + */ +static ssize_t smk_write_load_list(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, + struct list_head *rule_list, + struct mutex *rule_lock) +{ + struct smack_rule *rule; + char *data; + int rc = -EINVAL; + + /* + * No partial writes. + * Enough data must be present. + */ + if (*ppos != 0) + return -EINVAL; + /* + * Minor hack for backward compatibility + */ + if (count < (SMK_OLOADLEN) || count > SMK_LOADLEN) + return -EINVAL; + + data = kzalloc(SMK_LOADLEN, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + if (copy_from_user(data, buf, count) != 0) { + rc = -EFAULT; + goto out; + } + + /* + * More on the minor hack for backward compatibility + */ + if (count == (SMK_OLOADLEN)) + data[SMK_OLOADLEN] = '-'; + + rule = kzalloc(sizeof(*rule), GFP_KERNEL); + if (rule == NULL) { + rc = -ENOMEM; + goto out; + } + + if (smk_parse_rule(data, rule)) + 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 */ {""} }; |