[PATCH v2 6/9] selinux: avoid implicit conversions in services code

From: Christian Göttsche
Date: Fri Jul 28 2023 - 11:55:55 EST


Use u32 as the output parameter type in security_get_classes() and
security_get_permissions(), based on the type of the symtab nprim
member.

Declare the read-only class string parameter of
security_get_permissions() const.

Avoid several implicit conversions by using the identical type for the
destination.

Use the type identical to the source for local variables.

Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
v2: avoid declarations in init-clauses of for loops
---
security/selinux/include/security.h | 4 ++--
security/selinux/selinuxfs.c | 7 ++++---
security/selinux/ss/services.c | 23 ++++++++++++-----------
3 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index 668e393a9709..074d439fe9ad 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -312,9 +312,9 @@ int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
u32 *peer_sid);

int security_get_classes(struct selinux_policy *policy,
- char ***classes, int *nclasses);
+ char ***classes, u32 *nclasses);
int security_get_permissions(struct selinux_policy *policy,
- char *class, char ***perms, int *nperms);
+ const char *class, char ***perms, u32 *nperms);
int security_get_reject_unknown(void);
int security_get_allow_unknown(void);

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index f79e96f0f221..b969e87fd870 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1798,7 +1798,8 @@ static int sel_make_perm_files(struct selinux_policy *newpolicy,
char *objclass, int classvalue,
struct dentry *dir)
{
- int i, rc, nperms;
+ u32 i, nperms;
+ int rc;
char **perms;

rc = security_get_permissions(newpolicy, objclass, &perms, &nperms);
@@ -1868,8 +1869,8 @@ static int sel_make_classes(struct selinux_policy *newpolicy,
struct dentry *class_dir,
unsigned long *last_class_ino)
{
-
- int rc, nclasses, i;
+ u32 i, nclasses;
+ int rc;
char **classes;

rc = security_get_classes(newpolicy, &classes, &nclasses);
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index cf4b87ec4a0e..3a03243f52e7 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -856,7 +856,7 @@ int security_bounded_transition(u32 old_sid, u32 new_sid)
struct sidtab *sidtab;
struct sidtab_entry *old_entry, *new_entry;
struct type_datum *type;
- int index;
+ u32 index;
int rc;

if (!selinux_initialized())
@@ -1511,7 +1511,7 @@ static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
return -ENOMEM;

if (!selinux_initialized()) {
- int i;
+ u32 i;

for (i = 1; i < SECINITSID_NUM; i++) {
const char *s = initial_sid_to_string[i];
@@ -2821,7 +2821,6 @@ static inline int __security_genfs_sid(struct selinux_policy *policy,
{
struct policydb *policydb = &policy->policydb;
struct sidtab *sidtab = policy->sidtab;
- int len;
u16 sclass;
struct genfs *genfs;
struct ocontext *c;
@@ -2843,7 +2842,7 @@ static inline int __security_genfs_sid(struct selinux_policy *policy,
return -ENOENT;

for (c = genfs->head; c; c = c->next) {
- len = strlen(c->u.name);
+ size_t len = strlen(c->u.name);
if ((!c->v.sclass || sclass == c->v.sclass) &&
(strncmp(c->u.name, path, len) == 0))
break;
@@ -3331,7 +3330,7 @@ static int get_classes_callback(void *k, void *d, void *args)
{
struct class_datum *datum = d;
char *name = k, **classes = args;
- int value = datum->value - 1;
+ u32 value = datum->value - 1;

classes[value] = kstrdup(name, GFP_ATOMIC);
if (!classes[value])
@@ -3341,7 +3340,7 @@ static int get_classes_callback(void *k, void *d, void *args)
}

int security_get_classes(struct selinux_policy *policy,
- char ***classes, int *nclasses)
+ char ***classes, u32 *nclasses)
{
struct policydb *policydb;
int rc;
@@ -3357,7 +3356,8 @@ int security_get_classes(struct selinux_policy *policy,
rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
*classes);
if (rc) {
- int i;
+ u32 i;
+
for (i = 0; i < *nclasses; i++)
kfree((*classes)[i]);
kfree(*classes);
@@ -3371,7 +3371,7 @@ static int get_permissions_callback(void *k, void *d, void *args)
{
struct perm_datum *datum = d;
char *name = k, **perms = args;
- int value = datum->value - 1;
+ u32 value = datum->value - 1;

perms[value] = kstrdup(name, GFP_ATOMIC);
if (!perms[value])
@@ -3381,10 +3381,11 @@ static int get_permissions_callback(void *k, void *d, void *args)
}

int security_get_permissions(struct selinux_policy *policy,
- char *class, char ***perms, int *nperms)
+ const char *class, char ***perms, u32 *nperms)
{
struct policydb *policydb;
- int rc, i;
+ u32 i;
+ int rc;
struct class_datum *match;

policydb = &policy->policydb;
@@ -3599,7 +3600,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
/* Check to see if the rule contains any selinux fields */
int selinux_audit_rule_known(struct audit_krule *rule)
{
- int i;
+ u32 i;

for (i = 0; i < rule->field_count; i++) {
struct audit_field *f = &rule->fields[i];
--
2.40.1