From: Richard Guy Briggs <rgb@redhat.com>
Date: Wed, 20 May 2020 14:47:13 -0400
Subject: audit: add subj creds to NETFILTER_CFG record to
Patch-mainline: v5.8-rc1
Git-commit: 9d44a121c5a79bc8a9d67c058456bd52a83c79e7
References: bsc#1176447

Some table unregister actions seem to be initiated by the kernel to
garbage collect unused tables that are not initiated by any userspace
actions.  It was found to be necessary to add the subject credentials to
cover this case to reveal the source of these actions.  A sample record:

The uid, auid, tty, ses and exe fields have not been included since they
are in the SYSCALL record and contain nothing useful in the non-user
context.

Here are two sample orphaned records:

  type=NETFILTER_CFG msg=audit(2020-05-20 12:14:36.505:5) : table=filter family=ipv4 entries=0 op=register pid=1 subj=kernel comm=swapper/0

  type=NETFILTER_CFG msg=audit(2020-05-20 12:15:27.701:301) : table=nat family=bridge entries=0 op=unregister pid=30 subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:1

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 kernel/auditsc.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2560,12 +2560,18 @@ void __audit_log_nfcfg(const char *name,
 		       enum audit_nfcfgop op)
 {
 	struct audit_buffer *ab;
+	char comm[sizeof(current->comm)];
 
 	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_NETFILTER_CFG);
 	if (!ab)
 		return;
 	audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
 			 name, af, nentries, audit_nfcfgs[op].s);
+
+	audit_log_format(ab, " pid=%u", task_pid_nr(current));
+	audit_log_task_context(ab); /* subj= */
+	audit_log_format(ab, " comm=");
+	audit_log_untrustedstring(ab, get_task_comm(comm, current));
 	audit_log_end(ab);
 }
 EXPORT_SYMBOL_GPL(__audit_log_nfcfg);