diff options
Diffstat (limited to 'security/smack/smack_access.c')
| -rw-r--r-- | security/smack/smack_access.c | 54 |
1 files changed, 41 insertions, 13 deletions
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index 42becbc1ce3..7ba8478f599 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -67,6 +67,46 @@ static u32 smack_next_secid = 10; int log_policy = SMACK_AUDIT_DENIED; /** + * smk_access_entry - look up matching access rule + * @subject_label: a pointer to the subject's Smack label + * @object_label: a pointer to the object's Smack label + * + * This function looks up the subject/object pair in the + * access rule list and returns pointer to the matching rule if found, + * NULL otherwise. + * + * NOTE: + * Even though Smack labels are usually shared on smack_list + * labels that come in off the network can't be imported + * and added to the list for locking reasons. + * + * Therefore, it is necessary to check the contents of the labels, + * not just the pointer values. Of course, in most cases the labels + * will be on the list, so checking the pointers may be a worthwhile + * optimization. + */ +int smk_access_entry(char *subject_label, char *object_label) +{ + u32 may = MAY_NOT; + struct smack_rule *srp; + + rcu_read_lock(); + list_for_each_entry_rcu(srp, &smack_rule_list, list) { + if (srp->smk_subject == subject_label || + strcmp(srp->smk_subject, subject_label) == 0) { + if (srp->smk_object == object_label || + strcmp(srp->smk_object, object_label) == 0) { + may = srp->smk_access; + break; + } + } + } + rcu_read_unlock(); + + return may; +} + +/** * smk_access - determine if a subject has a specific access to an object * @subject_label: a pointer to the subject's Smack label * @object_label: a pointer to the object's Smack label @@ -90,7 +130,6 @@ int smk_access(char *subject_label, char *object_label, int request, struct smk_audit_info *a) { u32 may = MAY_NOT; - struct smack_rule *srp; int rc = 0; /* @@ -144,18 +183,7 @@ int smk_access(char *subject_label, char *object_label, int request, * access (e.g. read is included in readwrite) it's * good. */ - rcu_read_lock(); - list_for_each_entry_rcu(srp, &smack_rule_list, list) { - if (srp->smk_subject == subject_label || - strcmp(srp->smk_subject, subject_label) == 0) { - if (srp->smk_object == object_label || - strcmp(srp->smk_object, object_label) == 0) { - may = srp->smk_access; - break; - } - } - } - rcu_read_unlock(); + may = smk_access_entry(subject_label, object_label); /* * This is a bit map operation. */ |