[PATCH v12 03/25] LSM: Use lsmblob in security_audit_rule_match
Casey Schaufler
casey at schaufler-ca.com
Mon Dec 16 22:24:09 UTC 2019
Change the secid parameter of security_audit_rule_match
to a lsmblob structure pointer. Pass the entry from the
lsmblob structure for the approprite slot to the LSM hook.
Change the users of security_audit_rule_match to use the
lsmblob instead of a u32. In some cases this requires a
temporary conversion using lsmblob_init() that will go
away when other interfaces get converted.
Reviewed-by: Kees Cook <keescook at chromium.org>
Reviewed-by: John Johansen <john.johansen at canonical.com>
Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
---
include/linux/security.h | 7 ++++---
kernel/auditfilter.c | 7 +++++--
kernel/auditsc.c | 14 ++++++++++----
security/integrity/ima/ima.h | 4 ++--
security/integrity/ima/ima_policy.c | 7 +++++--
security/security.c | 18 +++++++++++++++---
6 files changed, 41 insertions(+), 16 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index b74dc70088ca..9c6dbe248eaf 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1837,7 +1837,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
#ifdef CONFIG_SECURITY
int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
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 lsmblob *blob, u32 field, u32 op,
+ void *lsmrule);
void security_audit_rule_free(void *lsmrule);
#else
@@ -1853,8 +1854,8 @@ 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 lsmblob *blob, u32 field,
+ u32 op, void *lsmrule)
{
return 0;
}
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index b0126e9c0743..356db1dd276c 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1325,6 +1325,7 @@ int audit_filter(int msgtype, unsigned int listtype)
struct audit_field *f = &e->rule.fields[i];
pid_t pid;
u32 sid;
+ struct lsmblob blob;
switch (f->type) {
case AUDIT_PID:
@@ -1355,8 +1356,10 @@ int audit_filter(int msgtype, unsigned int listtype)
case AUDIT_SUBJ_CLR:
if (f->lsm_rule) {
security_task_getsecid(current, &sid);
- result = security_audit_rule_match(sid,
- f->type, f->op, f->lsm_rule);
+ lsmblob_init(&blob, sid);
+ result = security_audit_rule_match(
+ &blob, f->type,
+ f->op, f->lsm_rule);
}
break;
case AUDIT_EXE:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4effe01ebbe2..7566e5b1c419 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -445,6 +445,7 @@ static int audit_filter_rules(struct task_struct *tsk,
const struct cred *cred;
int i, need_sid = 1;
u32 sid;
+ struct lsmblob blob;
unsigned int sessionid;
cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
@@ -643,7 +644,9 @@ static int audit_filter_rules(struct task_struct *tsk,
security_task_getsecid(tsk, &sid);
need_sid = 0;
}
- result = security_audit_rule_match(sid, f->type,
+ lsmblob_init(&blob, sid);
+ result = security_audit_rule_match(&blob,
+ f->type,
f->op,
f->lsm_rule);
}
@@ -658,15 +661,17 @@ static int audit_filter_rules(struct task_struct *tsk,
if (f->lsm_rule) {
/* Find files that match */
if (name) {
+ lsmblob_init(&blob, name->osid);
result = security_audit_rule_match(
- name->osid,
+ &blob,
f->type,
f->op,
f->lsm_rule);
} else if (ctx) {
list_for_each_entry(n, &ctx->names_list, list) {
+ lsmblob_init(&blob, n->osid);
if (security_audit_rule_match(
- n->osid,
+ &blob,
f->type,
f->op,
f->lsm_rule)) {
@@ -678,7 +683,8 @@ 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,
+ lsmblob_init(&blob, ctx->ipc.osid);
+ if (security_audit_rule_match(&blob,
f->type, f->op,
f->lsm_rule))
++result;
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index df4ca482fb53..d95b0ece7434 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -381,8 +381,8 @@ static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
return -EINVAL;
}
-static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
- void *lsmrule)
+static inline int security_filter_rule_match(struct lsmblob *blob, 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 f19a895ad7cd..193ddd55420b 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -414,6 +414,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
u32 osid;
+ struct lsmblob blob;
if (!rule->lsm[i].rule)
continue;
@@ -423,7 +424,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
case LSM_OBJ_ROLE:
case LSM_OBJ_TYPE:
security_inode_getsecid(inode, &osid);
- rc = security_filter_rule_match(osid,
+ lsmblob_init(&blob, osid);
+ rc = security_filter_rule_match(&blob,
rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule);
@@ -431,7 +433,8 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
- rc = security_filter_rule_match(secid,
+ lsmblob_init(&blob, secid);
+ rc = security_filter_rule_match(&blob,
rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule);
diff --git a/security/security.c b/security/security.c
index a89634af639a..bfea9739c084 100644
--- a/security/security.c
+++ b/security/security.c
@@ -439,7 +439,7 @@ static int lsm_append(const char *new, char **result)
/*
* Current index to use while initializing the lsmblob secid list.
*/
-static int lsm_slot __initdata;
+static int lsm_slot __lsm_ro_after_init;
/**
* security_add_hooks - Add a modules hooks to the hook lists.
@@ -2412,9 +2412,21 @@ void security_audit_rule_free(void *lsmrule)
call_void_hook(audit_rule_free, lsmrule);
}
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
+ void *lsmrule)
{
- return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
+ struct security_hook_list *hp;
+ int rc;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
+ field, op, lsmrule);
+ if (rc != 0)
+ return rc;
+ }
+ return 0;
}
#endif /* CONFIG_AUDIT */
--
2.20.1
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