[RFC v2 PATCH 2/2] kernel: Add SELinux SCTP protocol support

On Thu, Mar 02, 2017 at 03:45:40PM -0500, Stephen Smalley wrote:

On Wed, 2017-02-22 at 17:03 +0000, Richard Haines wrote:

<snip>

quoted

+	return err;
+}
+
+static int selinux_sctp_accept_conn(struct sctp_endpoint *ep,
+				????struct sk_buff *skb)
+{
+	struct sk_security_struct *sksec = ep->base.sk->sk_security;
+	int err;
+	u32 connsid;
+	u32 peersid;
+
+	/* Have COOKIE ECHO so compute the MLS component for the
connection
+	?* and store the information in ep. This will only be used
by
+	?* TCP/peeloff connections as they cause a new socket to be
generated.

Not sure why you say TCP above. ?And won't this be true of accept()'d

Probably just a typo, should be SCTP instead.

sockets too in addition to peeloff ones?

Speaking of accept() path, I think we have an issue there with this
patch, because it's doing:

@@ -7683,8 +7717,6 @@ void sctp_copy_sock(struct sock *newsk, struct

sock *sk,
-       security_sk_clone(sk, newsk);

@@ -7829,6 +7862,11 @@ static void sctp_sock_migrate(struct sock *oldsk,

struct
+       security_sctp_sk_clone(oldep, oldsk, newsk);

But sctp_copy_sock() is called from places other than
sctp_sock_migrate, mainly:
net/sctp/ipv6.c:        sctp_copy_sock(newsk, sk, asoc);
net/sctp/protocol.c:    sctp_copy_sock(newsk, sk, asoc);
Which are on the accept() path.

Ideally it's better to keep the call to security_sctp_sk_clone in
sctp_copy_sock() to get those covered too.

  Marcelo

quoted

+	?* selinux_sctp_sk_clone() will then plug this into the new
socket
+	?* as described in Documentation/security/LSM-sctp.txt
+	?*/
+	err = selinux_skb_peerlbl_sid(skb, ep->base.sk->sk_family,
&peersid);
+	if (err)
+		return err;
+
+	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
+	if (err)
+		return err;
+
+	ep->secid = connsid;
+	ep->peer_secid = peersid;
+
+	return 0;
+}
+

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