diff options
Diffstat (limited to 'security/smack/smack_access.c')
| -rw-r--r-- | security/smack/smack_access.c | 70 |
1 files changed, 43 insertions, 27 deletions
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index 2e0b83e77ffe..ac0a2707f6d4 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -16,48 +16,42 @@ #include "smack.h" struct smack_known smack_known_huh = { - .smk_next = NULL, .smk_known = "?", .smk_secid = 2, .smk_cipso = NULL, }; struct smack_known smack_known_hat = { - .smk_next = &smack_known_huh, .smk_known = "^", .smk_secid = 3, .smk_cipso = NULL, }; struct smack_known smack_known_star = { - .smk_next = &smack_known_hat, .smk_known = "*", .smk_secid = 4, .smk_cipso = NULL, }; struct smack_known smack_known_floor = { - .smk_next = &smack_known_star, .smk_known = "_", .smk_secid = 5, .smk_cipso = NULL, }; struct smack_known smack_known_invalid = { - .smk_next = &smack_known_floor, .smk_known = "", .smk_secid = 6, .smk_cipso = NULL, }; struct smack_known smack_known_web = { - .smk_next = &smack_known_invalid, .smk_known = "@", .smk_secid = 7, .smk_cipso = NULL, }; -struct smack_known *smack_known = &smack_known_web; +LIST_HEAD(smack_known_list); /* * The initial value needs to be bigger than any of the @@ -87,7 +81,6 @@ static u32 smack_next_secid = 10; int smk_access(char *subject_label, char *object_label, int request) { u32 may = MAY_NOT; - struct smk_list_entry *sp; struct smack_rule *srp; /* @@ -139,9 +132,8 @@ int smk_access(char *subject_label, char *object_label, int request) * access (e.g. read is included in readwrite) it's * good. */ - for (sp = smack_list; sp != NULL; sp = sp->smk_next) { - srp = &sp->smk_rule; - + 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 || @@ -151,6 +143,7 @@ int smk_access(char *subject_label, char *object_label, int request) } } } + rcu_read_unlock(); /* * This is a bit map operation. */ @@ -162,8 +155,8 @@ int smk_access(char *subject_label, char *object_label, int request) /** * smk_curacc - determine if current has a specific access to an object - * @object_label: a pointer to the object's Smack label - * @request: the access requested, in "MAY" format + * @obj_label: a pointer to the object's Smack label + * @mode: the access requested, in "MAY" format * * This function checks the current subject label/object label pair * in the access rule list and returns 0 if the access is permitted, @@ -228,14 +221,17 @@ struct smack_known *smk_import_entry(const char *string, int len) mutex_lock(&smack_known_lock); - for (skp = smack_known; skp != NULL; skp = skp->smk_next) - if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) + found = 0; + list_for_each_entry_rcu(skp, &smack_known_list, list) { + if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) { + found = 1; break; + } + } - if (skp == NULL) { + if (found == 0) { skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL); if (skp != NULL) { - skp->smk_next = smack_known; strncpy(skp->smk_known, smack, SMK_MAXLEN); skp->smk_secid = smack_next_secid++; skp->smk_cipso = NULL; @@ -244,8 +240,7 @@ struct smack_known *smk_import_entry(const char *string, int len) * Make sure that the entry is actually * filled before putting it on the list. */ - smp_mb(); - smack_known = skp; + list_add_rcu(&skp->list, &smack_known_list); } } @@ -266,6 +261,9 @@ char *smk_import(const char *string, int len) { struct smack_known *skp; + /* labels cannot begin with a '-' */ + if (string[0] == '-') + return NULL; skp = smk_import_entry(string, len); if (skp == NULL) return NULL; @@ -283,14 +281,19 @@ char *smack_from_secid(const u32 secid) { struct smack_known *skp; - for (skp = smack_known; skp != NULL; skp = skp->smk_next) - if (skp->smk_secid == secid) + rcu_read_lock(); + list_for_each_entry_rcu(skp, &smack_known_list, list) { + if (skp->smk_secid == secid) { + rcu_read_unlock(); return skp->smk_known; + } + } /* * If we got this far someone asked for the translation * of a secid that is not on the list. */ + rcu_read_unlock(); return smack_known_invalid.smk_known; } @@ -305,9 +308,14 @@ u32 smack_to_secid(const char *smack) { struct smack_known *skp; - for (skp = smack_known; skp != NULL; skp = skp->smk_next) - if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) + rcu_read_lock(); + list_for_each_entry_rcu(skp, &smack_known_list, list) { + if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) { + rcu_read_unlock(); return skp->smk_secid; + } + } + rcu_read_unlock(); return 0; } @@ -332,7 +340,8 @@ void smack_from_cipso(u32 level, char *cp, char *result) struct smack_known *kp; char *final = NULL; - for (kp = smack_known; final == NULL && kp != NULL; kp = kp->smk_next) { + rcu_read_lock(); + list_for_each_entry(kp, &smack_known_list, list) { if (kp->smk_cipso == NULL) continue; @@ -344,6 +353,7 @@ void smack_from_cipso(u32 level, char *cp, char *result) spin_unlock_bh(&kp->smk_cipsolock); } + rcu_read_unlock(); if (final == NULL) final = smack_known_huh.smk_known; strncpy(result, final, SMK_MAXLEN); @@ -360,13 +370,19 @@ void smack_from_cipso(u32 level, char *cp, char *result) int smack_to_cipso(const char *smack, struct smack_cipso *cp) { struct smack_known *kp; + int found = 0; - for (kp = smack_known; kp != NULL; kp = kp->smk_next) + rcu_read_lock(); + list_for_each_entry_rcu(kp, &smack_known_list, list) { if (kp->smk_known == smack || - strcmp(kp->smk_known, smack) == 0) + strcmp(kp->smk_known, smack) == 0) { + found = 1; break; + } + } + rcu_read_unlock(); - if (kp == NULL || kp->smk_cipso == NULL) + if (found == 0 || kp->smk_cipso == NULL) return -ENOENT; memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso)); |