Re: [PATCH V2] selinux: Add SCTP support

On Wed, Dec 6, 2017 at 5:17 AM, Richard Haines
[off-list ref] wrote:

The SELinux SCTP implementation is explained in:
Documentation/security/SELinux-sctp.rst

Signed-off-by: Richard Haines <redacted>
---
V2 Changes
Remove lock from selinux_sctp_assoc_request()
Fix selinux_sctp_sk_clone() kbuild test robot catch [1]

[1] https://marc.info/?l=selinux&m=151198281817779&w=2

 Documentation/security/SELinux-sctp.rst | 104 ++++++++++++
 security/selinux/hooks.c                | 270 +++++++++++++++++++++++++++++---
 security/selinux/include/classmap.h     |   2 +-
 security/selinux/include/netlabel.h     |  20 ++-
 security/selinux/include/objsec.h       |   4 +
 security/selinux/netlabel.c             | 144 +++++++++++++++--
 6 files changed, 512 insertions(+), 32 deletions(-)
 create mode 100644 Documentation/security/SELinux-sctp.rst

I just went through these patches again, and I think they look pretty
good.  There is one small cosmetic nit (see below), but that should be
a quick fix.

As Dave already said, let's give the SCTP folks some time to look
things over before I merge anything.  If we haven't heard anything by
next week, I'll ping Vlad to see if I can get him to take a look.

+/**
+ * selinux_netlbl_socket_connect - Label a client-side socket on connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket with NetLabel using the given address.
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
+{
+       int rc;
+       struct sk_security_struct *sksec = sk->sk_security;
+
+       if (sksec->nlbl_state != NLBL_REQSKB &&
+           sksec->nlbl_state != NLBL_CONNLABELED)
+               return 0;
+
+       lock_sock(sk);
+       rc = selinux_netlbl_socket_connect_helper(sk, addr);
        release_sock(sk);
+
+       return rc;
+}
+
+/**
+ * selinux_netlbl_sctp_socket_connect - Label an SCTP client-side socket on a
+ * connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket with NetLabel using the given address
+ * when called by the SCTP protocol layer. The situations handled are:
+ * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2), whenever a new IP address
+ * is added or when a new primary address is selected. Note that an SCTP
+ * connect(2) call happens before the SCTP protocol layer and is handled via
+ * selinux_netlbl_socket_connect()
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_sctp_socket_connect(struct sock *sk, struct sockaddr *addr)
+{
+       int rc;
+       struct sk_security_struct *sksec = sk->sk_security;
+
+       if (sksec->nlbl_state != NLBL_REQSKB &&
+           sksec->nlbl_state != NLBL_CONNLABELED)
+               return 0;
+
+       rc = selinux_netlbl_socket_connect_helper(sk, addr);
+
        return rc;
 }

My apologies, I should have noticed this sooner ... If the only
difference between selinux_netlbl_socket_connect() and
selinux_netlbl_sctp_socket_connect() is that the SCTP variant takes a
lock, why not simply rename selinux_netlbl_sctp_socket_connect() to
selinux_netlbl_socket_connect_locked()?  There is nothing really SCTP
specific here, aside from the comment header, which should already be
covered elsewhere.

[NOTE TO MYSELF: pick shorter function names next time, oof.]

-- 
paul moore
www.paul-moore.com