[PATCH] audit: audit feature to send logs to kmsg always
This adds a new 'audit feature' bit which allows userspace to set it
such that the audit messages will always be sent to kmsg, even in the
advent of a registered userspace daemon.
Signed-off-by: William Roberts <w.roberts(a)sta.samsung.com>
---
include/uapi/linux/audit.h | 3 ++-
kernel/audit.c | 20 ++++++++++++++------
2 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 9539ea9..8464d7c 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -382,7 +382,8 @@ struct audit_features {
#define AUDIT_FEATURE_ONLY_UNSET_LOGINUID 0
#define AUDIT_FEATURE_LOGINUID_IMMUTABLE 1
-#define AUDIT_LAST_FEATURE AUDIT_FEATURE_LOGINUID_IMMUTABLE
+#define AUDIT_FEATURE_ALWAYS_LOG_KMSG 2
+#define AUDIT_LAST_FEATURE AUDIT_FEATURE_ALWAYS_LOG_KMSG
#define audit_feature_valid(x) ((x) >= 0 && (x) <= AUDIT_LAST_FEATURE)
#define AUDIT_FEATURE_TO_MASK(x) (1 << ((x) & 31)) /* mask for __u32 */
diff --git a/kernel/audit.c b/kernel/audit.c
index 900d61d..e40328e 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -145,9 +145,10 @@ static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
.features = 0,
.lock = 0,};
-static char *audit_feature_names[2] = {
+static char *audit_feature_names[3] = {
"only_unset_loginuid",
"loginuid_immutable",
+ "log_kmsg_always"
};
@@ -372,11 +373,8 @@ static void audit_hold_skb(struct sk_buff *skb)
kfree_skb(skb);
}
-/*
- * For one reason or another this nlh isn't getting delivered to the userspace
- * audit daemon, just send it to printk.
- */
-static void audit_printk_skb(struct sk_buff *skb)
+/* Just printks the skb, no audit_hold or free of any kind */
+static void __audit_printk_skb(struct sk_buff *skb)
{
struct nlmsghdr *nlh = nlmsg_hdr(skb);
char *data = nlmsg_data(nlh);
@@ -387,7 +385,15 @@ static void audit_printk_skb(struct sk_buff *skb)
else
audit_log_lost("printk limit exceeded\n");
}
+}
+/*
+ * For one reason or another this nlh isn't getting delivered to the userspace
+ * audit daemon, just send it to printk.
+ */
+static void audit_printk_skb(struct sk_buff *skb)
+{
+ __audit_printk_skb(skb);
audit_hold_skb(skb);
}
@@ -1800,6 +1806,8 @@ void audit_log_end(struct audit_buffer *ab)
nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
if (audit_pid) {
+ if(is_audit_feature_set(AUDIT_FEATURE_ALWAYS_LOG_KMSG))
+ __audit_printk_skb(ab->skb);
skb_queue_tail(&audit_skb_queue, ab->skb);
wake_up_interruptible(&kauditd_wait);
} else {
--
1.8.2.3