From 0e94ae17c857b3835a2b8ea46ce44b5da4e2cc5d Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Tue, 18 Oct 2011 21:21:36 +0300 Subject: 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 Signed-off-by: Casey Schaufler --- security/smack/smack.h | 1 + security/smack/smack_access.c | 27 ++++++++++++++++++-------- security/smack/smackfs.c | 45 ++++++++++++++++++++++++++++--------------- 3 files changed, 50 insertions(+), 23 deletions(-) (limited to 'security') diff --git a/security/smack/smack.h b/security/smack/smack.h index 9da2b2d..2ad0065 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -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 *); diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index a885f62..cc7cb6e 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -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; 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 @@ 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 */ {""} }; -- cgit v1.1