[PATCH V3 2/3] audit: add AUDIT_SESSIONID_SET support
Add AUDIT_SESSIONID_SET field to indicate the sessionID is set in
filters rather than depending on an in-band signal to indicate it.
https://github.com/linux-audit/audit-kernel/wiki/RFE-Session-ID-User-Filter
RFE Session ID User Filter
https://github.com/linux-audit/audit-kernel/issues/4
RFE: add a session ID filter to the kernel's user filter
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
include/linux/audit.h | 10 ++++++++++
include/uapi/linux/audit.h | 1 +
kernel/auditfilter.c | 3 +++
kernel/auditsc.c | 7 ++++---
4 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 9d4443f..2392442 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -552,6 +552,16 @@ static inline bool audit_loginuid_set(struct task_struct *tsk)
return uid_valid(audit_get_loginuid(tsk));
}
+static inline bool sessionid_valid(unsigned int sessionid)
+{
+ return sessionid != (unsigned int) -1;
+}
+
+static inline bool audit_sessionid_set(struct task_struct *tsk)
+{
+ return sessionid_valid(audit_get_sessionid(tsk));
+}
+
static inline void audit_log_string(struct audit_buffer *ab, const char *buf)
{
audit_log_n_string(ab, buf, strlen(buf));
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index b3140eb..a4048bc 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -253,6 +253,7 @@
#define AUDIT_OBJ_LEV_HIGH 23
#define AUDIT_LOGINUID_SET 24
#define AUDIT_SESSIONID 25 /* Session ID */
+#define AUDIT_SESSIONID_SET 26 /* Session ID set or not */
/* These are ONLY useful when checking
* at syscall exit time (AUDIT_AT_EXIT). */
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 1c60fcf..47eaaba 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -387,6 +387,7 @@ static int audit_field_valid(struct audit_entry *entry, struct
audit_field *f)
case AUDIT_FILTERKEY:
break;
case AUDIT_LOGINUID_SET:
+ case AUDIT_SESSIONID_SET:
if ((f->val != 0) && (f->val != 1))
return -EINVAL;
/* FALL THROUGH */
@@ -478,6 +479,8 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data
*data,
goto exit_free;
break;
case AUDIT_SESSIONID:
+ if (!sessionid_valid(f->val))
+ goto exit_free;
case AUDIT_ARCH:
entry->rule.arch_f = f;
break;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 52f7a61..4df536b 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -447,7 +447,6 @@ static int audit_filter_rules(struct task_struct *tsk,
const struct cred *cred;
int i, need_sid = 1;
u32 sid;
- unsigned int sessionid;
cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
@@ -511,8 +510,7 @@ static int audit_filter_rules(struct task_struct *tsk,
result = audit_gid_comparator(cred->fsgid, f->op, f->gid);
break;
case AUDIT_SESSIONID:
- sessionid = audit_get_sessionid(current);
- result = audit_comparator(sessionid, f->op, f->val);
+ result = audit_comparator(audit_get_sessionid(tsk), f->op, f->val);
break;
case AUDIT_PERS:
result = audit_comparator(tsk->personality, f->op, f->val);
@@ -614,6 +612,9 @@ static int audit_filter_rules(struct task_struct *tsk,
case AUDIT_LOGINUID_SET:
result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
break;
+ case AUDIT_SESSIONID_SET:
+ result = audit_comparator(audit_sessionid_set(tsk), f->op, f->val);
+ break;
case AUDIT_SUBJ_USER:
case AUDIT_SUBJ_ROLE:
case AUDIT_SUBJ_TYPE:
--
1.7.1