[PATCH] Audit: make audit=0 actually turn off audit
Currently audit=0 on the kernel command line does absolutely nothing.
Audit always loads and always uses its resources such as creating the
kernel netlink socket. This patch causes audit=0 to actually disable
audit. Audit will use no resources and starting the userspace auditd
daemon will not cause the kernel audit system to activate.
Signed-off-by: Eric Paris <eparis(a)redhat.com>
---
kernel/audit.c | 28 +++++++++++++++++++++-------
1 files changed, 21 insertions(+), 7 deletions(-)
diff --git a/kernel/audit.c b/kernel/audit.c
index 4414e93..d8646c2 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -61,8 +61,11 @@
#include "audit.h"
-/* No auditing will take place until audit_initialized != 0.
+/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
* (Initialization happens after skb_init is called.) */
+#define AUDIT_DISABLED -1
+#define AUDIT_UNINITIALIZED 0
+#define AUDIT_INITIALIZED 1
static int audit_initialized;
#define AUDIT_OFF 0
@@ -965,6 +968,9 @@ static int __init audit_init(void)
{
int i;
+ if (audit_initialized == AUDIT_DISABLED)
+ return 0;
+
printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
audit_default ? "enabled" : "disabled");
audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
@@ -976,7 +982,7 @@ static int __init audit_init(void)
skb_queue_head_init(&audit_skb_queue);
skb_queue_head_init(&audit_skb_hold_queue);
- audit_initialized = 1;
+ audit_initialized = AUDIT_INITIALIZED;
audit_enabled = audit_default;
audit_ever_enabled |= !!audit_default;
@@ -999,13 +1005,21 @@ __initcall(audit_init);
static int __init audit_enable(char *str)
{
audit_default = !!simple_strtol(str, NULL, 0);
- printk(KERN_INFO "audit: %s%s\n",
- audit_default ? "enabled" : "disabled",
- audit_initialized ? "" : " (after initialization)");
- if (audit_initialized) {
+ if (!audit_default)
+ audit_initialized = AUDIT_DISABLED;
+
+ printk(KERN_INFO "audit: %s", audit_default ? "enabled" :
"disabled");
+
+ if (audit_initialized == AUDIT_INITIALIZED) {
audit_enabled = audit_default;
audit_ever_enabled |= !!audit_default;
+ } else if (audit_initialized == AUDIT_UNINITIALIZED) {
+ printk(" (after initialization)");
+ } else {
+ printk(" (until reboot)");
}
+ printk("\n");
+
return 1;
}
@@ -1146,7 +1160,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx,
gfp_t gfp_mask,
int reserve;
unsigned long timeout_start = jiffies;
- if (!audit_initialized)
+ if (audit_initialized != AUDIT_INITIALIZED)
return NULL;
if (unlikely(audit_filter_type(type)))