The attached patch addresses the problem with getting the audit daemon

shutdown credential information. It creates a new message type 
AUDIT_TERM_INFO, which is used by the audit daemon to query who issued the 
shutdown. 

It requires the placement of a hook function that gathers the information. The 
hook is after the DAC & MAC checks and before the function returns. Racing 
threads could overwrite the uid & pid - but they would have to be root and 
have policy that allows signalling the audit daemon. That should be a 
manageable risk.

The userspace component will be released later in audit 0.7.2. When it 
receives the TERM signal, it queries the kernel for shutdown information. 
When it receives it, it writes the message and exits. The message looks 
like this:

type=DAEMON msg=auditd(1114551182.000) auditd normal halt, sending pid=2650 
uid=525, auditd pid=1685

Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 37b3ac9..f1bf665 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1056,3 +1056,22 @@ int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
 	context->aux = (void *)ax;
 	return 0;
 }
+
+void audit_signal_info(int sig, struct task_struct *t)
+{
+	extern pid_t audit_sig_pid;
+	extern uid_t audit_sig_uid;
+	extern int audit_pid;
+
+	if (unlikely(audit_pid && t->pid == audit_pid)) {
+		if (sig == SIGTERM || sig == SIGHUP) {
+			struct audit_context *ctx = current->audit_context;
+			audit_sig_pid = current->pid;
+			if (ctx)
+				audit_sig_uid = ctx->loginuid;
+			else
+				audit_sig_uid = current->uid;
+		}
+	}
+}
+