Audit issue

[Alexander Viro]

On Wed, Oct 31, 2007 at 05:40:19PM -0400, Steve Grubb wrote:
> On Tuesday 30 October 2007 07:15:25 pm Alexander Viro wrote:
> > On Tue, Oct 30, 2007 at 07:07:29PM -0400, Steve Grubb wrote:
> > > On Tuesday 30 October 2007 03:04:54 pm Eric Paris wrote:
> > > > why is it acceptable to mandate audit=1 in gurb but not to mandate
> > > > 'don't use auditctl -e 0' ?? ????
> > >
> > > Its not that audit=1 is mandated. Its recommended. In the other case,
> > > temporarily taking the audit system offline should in no way impair the
> > > ability to start auditing again. It is required that an admin be able to
> > > track any users in the system if they are accessing files or attempting
> > > to make privileged calls.
> >
> > Ahem...  If you have it disabled for a while, what's going to do the
> > tracking until you reenable it?

Have fun...

diff --git a/kernel/audit.c b/kernel/audit.c
index f93c271..83227f8 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -70,6 +70,7 @@ static int	audit_initialized;
  * 1 - auditing enabled
  * 2 - auditing enabled and configuration is locked/unchangeable. */
 int		audit_enabled;
+int		audit_ever_enabled;
 
 /* Default state when kernel boots without any parameters. */
 static int	audit_default;
@@ -340,8 +341,10 @@ static int audit_set_enabled(int state, uid_t loginuid, u32 sid)
 		state, old, loginuid, res);
 
 	/* If we are allowed, make the change */
-	if (res == 1)
+	if (res == 1) {
 		audit_enabled = state;
+		audit_ever_enabled |= !!state;
+	}
 	/* Not allowed, update reason */
 	else if (rc == 0)
 		rc = -EPERM;
@@ -965,6 +968,7 @@ static int __init audit_init(void)
 	skb_queue_head_init(&audit_skb_queue);
 	audit_initialized = 1;
 	audit_enabled = audit_default;
+	audit_ever_enabled |= !!audit_default;
 
 	/* Register the callback with selinux.  This callback will be invoked
 	 * when a new policy is loaded. */
@@ -992,8 +996,10 @@ static int __init audit_enable(char *str)
 	printk(KERN_INFO "audit: %s%s\n",
 	       audit_default ? "enabled" : "disabled",
 	       audit_initialized ? "" : " (after initialization)");
-	if (audit_initialized)
+	if (audit_initialized) {
 		audit_enabled = audit_default;
+		audit_ever_enabled |= !!audit_default;
+	}
 	return 1;
 }
 
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index bce9ecd..250f00f 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -70,6 +70,7 @@
 #include "audit.h"
 
 extern struct list_head audit_filter_list[];
+extern int audit_ever_enabled;
 
 /* AUDIT_NAMES is the number of slots we reserve in the audit_context
  * for saving names from getname(). */
@@ -814,7 +815,7 @@ int audit_alloc(struct task_struct *tsk)
 	struct audit_context *context;
 	enum audit_state     state;
 
-	if (likely(!audit_enabled))
+	if (likely(!audit_ever_enabled))
 		return 0; /* Return if not auditing. */
 
 	state = audit_filter_task(tsk);