[PATCH v3] selinux: rate-limit unrecognized netlink message warnings in selinux_nlmsg_perm()

From: Vladis Dronov <vdronov@redhat.com>
To: Paul Moore <paul@paul-moore.com>,
	Stephen Smalley <sds@tycho.nsa.gov>,
	Eric Paris <eparis@parisplace.org>,
	James Morris <james.l.morris@oracle.com>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov
Cc: Vladis Dronov <vdronov@redhat.com>
Subject: [PATCH v3] selinux: rate-limit unrecognized netlink message warnings in selinux_nlmsg_perm()
Date: Fri, 13 Nov 2015 15:14:19 +0100	[thread overview]
Message-ID: <1447424059-11174-1-git-send-email-vdronov@redhat.com> (raw)

Any process is able to send netlink messages with invalid types.
Make the warning rate-limited to prevent too much log spam.

The warning is supposed to help to find misbehaving programs, so
print the triggering command name and pid.

Reported-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
 security/selinux/hooks.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index d0cfaa9..791fc46 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4785,11 +4785,12 @@ static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
 	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
 	if (err) {
 		if (err == -EINVAL) {
-			printk(KERN_WARNING
-			       "SELinux: unrecognized netlink message:"
-			       " protocol=%hu nlmsg_type=%hu sclass=%s\n",
+			pr_warn_ratelimited("SELinux: unrecognized netlink"
+			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
+			       " pig=%d comm=%s\n",
 			       sk->sk_protocol, nlh->nlmsg_type,
-			       secclass_map[sksec->sclass - 1].name);
+			       secclass_map[sksec->sclass - 1].name,
+			       task_pid_nr(current), current->comm);
 			if (!selinux_enforcing || security_get_allow_unknown())
 				err = 0;
 		}
-- 
2.6.2
