[PATCH v3 02/13] LSM: Use lsm_prop in security_audit_rule_match

From: Casey Schaufler
Date: Tue Sep 10 2024 - 14:52:09 EST


Change the secid parameter of security_audit_rule_match
to a lsm_prop structure pointer. Pass the entry from the
lsm_prop structure for the approprite slot to the LSM hook.

Change the users of security_audit_rule_match to use the
lsm_prop instead of a u32. The scaffolding function lsmprop_init()
fills the structure with the value of the old secid, ensuring that
it is available to the appropriate module hook. The sources of
the secid, security_task_getsecid() and security_inode_getsecid(),
will be converted to use the lsm_prop structure later in the series.
At that point the use of lsmprop_init() is dropped.

Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
include/linux/lsm_hook_defs.h | 3 ++-
include/linux/security.h | 7 ++++---
kernel/auditfilter.c | 11 +++++++----
kernel/auditsc.c | 18 ++++++++++++++----
security/apparmor/audit.c | 8 ++++++--
security/apparmor/include/audit.h | 2 +-
security/integrity/ima/ima.h | 2 +-
security/integrity/ima/ima_policy.c | 11 +++++++----
security/security.c | 7 ++++---
security/selinux/include/audit.h | 4 ++--
security/selinux/ss/services.c | 10 +++++++---
security/smack/smack_lsm.c | 11 ++++++++---
12 files changed, 63 insertions(+), 31 deletions(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 855db460e08b..0cc3c34f5bdf 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -416,7 +416,8 @@ LSM_HOOK(void, LSM_RET_VOID, key_post_create_or_update, struct key *keyring,
LSM_HOOK(int, 0, audit_rule_init, u32 field, u32 op, char *rulestr,
void **lsmrule, gfp_t gfp)
LSM_HOOK(int, 0, audit_rule_known, struct audit_krule *krule)
-LSM_HOOK(int, 0, audit_rule_match, u32 secid, u32 field, u32 op, void *lsmrule)
+LSM_HOOK(int, 0, audit_rule_match, struct lsm_prop *prop, u32 field, u32 op,
+ void *lsmrule)
LSM_HOOK(void, LSM_RET_VOID, audit_rule_free, void *lsmrule)
#endif /* CONFIG_AUDIT */

diff --git a/include/linux/security.h b/include/linux/security.h
index 1027c802cc8c..736fb1f87bf4 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -2071,7 +2071,8 @@ static inline void security_key_post_create_or_update(struct key *keyring,
int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule,
gfp_t gfp);
int security_audit_rule_known(struct audit_krule *krule);
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
+int security_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op,
+ void *lsmrule);
void security_audit_rule_free(void *lsmrule);

#else
@@ -2087,8 +2088,8 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
return 0;
}

-static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
- void *lsmrule)
+static inline int security_audit_rule_match(struct lsm_prop *prop, u32 field,
+ u32 op, void *lsmrule)
{
return 0;
}
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index d6ef4f4f9cba..5b47571ae4ee 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1339,8 +1339,8 @@ int audit_filter(int msgtype, unsigned int listtype)

for (i = 0; i < e->rule.field_count; i++) {
struct audit_field *f = &e->rule.fields[i];
+ struct lsm_prop prop = { };
pid_t pid;
- u32 sid;

switch (f->type) {
case AUDIT_PID:
@@ -1370,9 +1370,12 @@ int audit_filter(int msgtype, unsigned int listtype)
case AUDIT_SUBJ_SEN:
case AUDIT_SUBJ_CLR:
if (f->lsm_rule) {
- security_current_getsecid_subj(&sid);
- result = security_audit_rule_match(sid,
- f->type, f->op, f->lsm_rule);
+ /* scaffolding */
+ security_current_getsecid_subj(
+ &prop.scaffold.secid);
+ result = security_audit_rule_match(
+ &prop, f->type, f->op,
+ f->lsm_rule);
}
break;
case AUDIT_EXE:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 6f0d6fb6523f..effb1a7e0405 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -471,6 +471,7 @@ static int audit_filter_rules(struct task_struct *tsk,
const struct cred *cred;
int i, need_sid = 1;
u32 sid;
+ struct lsm_prop prop = { };
unsigned int sessionid;

if (ctx && rule->prio <= ctx->prio)
@@ -681,7 +682,10 @@ static int audit_filter_rules(struct task_struct *tsk,
security_current_getsecid_subj(&sid);
need_sid = 0;
}
- result = security_audit_rule_match(sid, f->type,
+ /* scaffolding */
+ prop.scaffold.secid = sid;
+ result = security_audit_rule_match(&prop,
+ f->type,
f->op,
f->lsm_rule);
}
@@ -696,15 +700,19 @@ static int audit_filter_rules(struct task_struct *tsk,
if (f->lsm_rule) {
/* Find files that match */
if (name) {
+ /* scaffolding */
+ prop.scaffold.secid = name->osid;
result = security_audit_rule_match(
- name->osid,
+ &prop,
f->type,
f->op,
f->lsm_rule);
} else if (ctx) {
list_for_each_entry(n, &ctx->names_list, list) {
+ /* scaffolding */
+ prop.scaffold.secid = n->osid;
if (security_audit_rule_match(
- n->osid,
+ &prop,
f->type,
f->op,
f->lsm_rule)) {
@@ -716,7 +724,9 @@ static int audit_filter_rules(struct task_struct *tsk,
/* Find ipc objects that match */
if (!ctx || ctx->type != AUDIT_IPC)
break;
- if (security_audit_rule_match(ctx->ipc.osid,
+ /* scaffolding */
+ prop.scaffold.secid = ctx->ipc.osid;
+ if (security_audit_rule_match(&prop,
f->type, f->op,
f->lsm_rule))
++result;
diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c
index 6b5181c668b5..87df6fa2a48d 100644
--- a/security/apparmor/audit.c
+++ b/security/apparmor/audit.c
@@ -264,13 +264,17 @@ int aa_audit_rule_known(struct audit_krule *rule)
return 0;
}

-int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
+int aa_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule)
{
struct aa_audit_rule *rule = vrule;
struct aa_label *label;
int found = 0;

- label = aa_secid_to_label(sid);
+ /* scaffolding */
+ if (!prop->apparmor.label && prop->scaffold.secid)
+ label = aa_secid_to_label(prop->scaffold.secid);
+ else
+ label = prop->apparmor.label;

if (!label)
return -ENOENT;
diff --git a/security/apparmor/include/audit.h b/security/apparmor/include/audit.h
index 0c8cc86b417b..e27229349abb 100644
--- a/security/apparmor/include/audit.h
+++ b/security/apparmor/include/audit.h
@@ -202,6 +202,6 @@ static inline int complain_error(int error)
void aa_audit_rule_free(void *vrule);
int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, gfp_t gfp);
int aa_audit_rule_known(struct audit_krule *rule);
-int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule);
+int aa_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule);

#endif /* __AA_AUDIT_H */
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index c51e24d24d1e..f17213520c36 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -555,7 +555,7 @@ static inline void ima_filter_rule_free(void *lsmrule)
{
}

-static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
+static inline int ima_filter_rule_match(struct lsm_prop *prop, u32 field, u32 op,
void *lsmrule)
{
return -EINVAL;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 09da8e639239..22a62e675ebc 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -635,7 +635,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
return false;
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
- u32 osid;
+ struct lsm_prop prop = { };

if (!lsm_rule->lsm[i].rule) {
if (!lsm_rule->lsm[i].args_p)
@@ -649,15 +649,18 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
case LSM_OBJ_USER:
case LSM_OBJ_ROLE:
case LSM_OBJ_TYPE:
- security_inode_getsecid(inode, &osid);
- rc = ima_filter_rule_match(osid, lsm_rule->lsm[i].type,
+ /* scaffolding */
+ security_inode_getsecid(inode, &prop.scaffold.secid);
+ rc = ima_filter_rule_match(&prop, lsm_rule->lsm[i].type,
Audit_equal,
lsm_rule->lsm[i].rule);
break;
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
- rc = ima_filter_rule_match(secid, lsm_rule->lsm[i].type,
+ /* scaffolding */
+ prop.scaffold.secid = secid;
+ rc = ima_filter_rule_match(&prop, lsm_rule->lsm[i].type,
Audit_equal,
lsm_rule->lsm[i].rule);
break;
diff --git a/security/security.c b/security/security.c
index 8cee5b6c6e6d..e06817ef4304 100644
--- a/security/security.c
+++ b/security/security.c
@@ -5399,7 +5399,7 @@ void security_audit_rule_free(void *lsmrule)

/**
* security_audit_rule_match() - Check if a label matches an audit rule
- * @secid: security label
+ * @prop: security label
* @field: LSM audit field
* @op: matching operator
* @lsmrule: audit rule
@@ -5410,9 +5410,10 @@ void security_audit_rule_free(void *lsmrule)
* Return: Returns 1 if secid matches the rule, 0 if it does not, -ERRNO on
* failure.
*/
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
+int security_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op,
+ void *lsmrule)
{
- return call_int_hook(audit_rule_match, secid, field, op, lsmrule);
+ return call_int_hook(audit_rule_match, prop, field, op, lsmrule);
}
#endif /* CONFIG_AUDIT */

diff --git a/security/selinux/include/audit.h b/security/selinux/include/audit.h
index 29c7d4c86f6d..7313c92d479b 100644
--- a/security/selinux/include/audit.h
+++ b/security/selinux/include/audit.h
@@ -41,7 +41,7 @@ void selinux_audit_rule_free(void *rule);

/**
* selinux_audit_rule_match - determine if a context ID matches a rule.
- * @sid: the context ID to check
+ * @prop: includes the context ID to check
* @field: the field this rule refers to
* @op: the operator the rule uses
* @rule: pointer to the audit rule to check against
@@ -49,7 +49,7 @@ void selinux_audit_rule_free(void *rule);
* Returns 1 if the context id matches the rule, 0 if it does not, and
* -errno on failure.
*/
-int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *rule);
+int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *rule);

/**
* selinux_audit_rule_known - check to see if rule contains selinux fields.
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index e33e55384b75..74b1aafda399 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3633,7 +3633,7 @@ int selinux_audit_rule_known(struct audit_krule *rule)
return 0;
}

-int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
+int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule)
{
struct selinux_state *state = &selinux_state;
struct selinux_policy *policy;
@@ -3659,10 +3659,14 @@ int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
goto out;
}

- ctxt = sidtab_search(policy->sidtab, sid);
+ /* scaffolding */
+ if (!prop->selinux.secid && prop->scaffold.secid)
+ prop->selinux.secid = prop->scaffold.secid;
+
+ ctxt = sidtab_search(policy->sidtab, prop->selinux.secid);
if (unlikely(!ctxt)) {
WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
- sid);
+ prop->selinux.secid);
match = -ENOENT;
goto out;
}
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 4164699cd4f6..7868268032a3 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4776,7 +4776,7 @@ static int smack_audit_rule_known(struct audit_krule *krule)

/**
* smack_audit_rule_match - Audit given object ?
- * @secid: security id for identifying the object to test
+ * @prop: security id for identifying the object to test
* @field: audit rule flags given from user-space
* @op: required testing operator
* @vrule: smack internal rule presentation
@@ -4784,7 +4784,8 @@ static int smack_audit_rule_known(struct audit_krule *krule)
* The core Audit hook. It's used to take the decision of
* whether to audit or not to audit a given object.
*/
-static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
+static int smack_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op,
+ void *vrule)
{
struct smack_known *skp;
char *rule = vrule;
@@ -4797,7 +4798,11 @@ static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
return 0;

- skp = smack_from_secid(secid);
+ /* scaffolding */
+ if (!prop->smack.skp && prop->scaffold.secid)
+ skp = smack_from_secid(prop->scaffold.secid);
+ else
+ skp = prop->smack.skp;

/*
* No need to do string comparisons. If a match occurs,
--
2.46.0