Patch "libceph: verify authorize reply on connect" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

libceph: verify authorize reply on connect

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
libceph-verify-authorize-reply-on-connect.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Ilya Dryomov <[email protected]>
Date: Fri, 2 Dec 2016 16:35:09 +0100
Subject: libceph: verify authorize reply on connect

From: Ilya Dryomov <[email protected]>

commit 5c056fdc5b474329037f2aa18401bd73033e0ce0 upstream.

After sending an authorizer (ceph_x_authorize_a + ceph_x_authorize_b), the client gets back a ceph_x_authorize_reply, which it is supposed to verify to ensure the authenticity and protect against replay attacks. The code for doing this is there (ceph_x_verify_authorizer_reply(), ceph_auth_verify_authorizer_reply() + plumbing), but it is never invoked by the the messenger.

AFAICT this goes back to 2009, when ceph authentication protocols support was added to the kernel client in 4e7a5dcd1bba ("ceph:
negotiate authentication protocol; implement AUTH_NONE protocol").

The second param of ceph_connection_operations::verify_authorizer_reply is unused all the way down. Pass 0 to facilitate backporting, and kill it in the next commit.

---
 net/ceph/messenger.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

@@ -2042,6 +2042,19 @@ static int process_connect(struct ceph_c
 
 	dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
 
+	if (con->auth_reply_buf) {
+		/*
+		 * Any connection that defines ->get_authorizer()
+		 * should also define ->verify_authorizer_reply().
+		 * See get_connect_authorizer().
+		 */
+		ret = con->ops->verify_authorizer_reply(con, 0);
+		if (ret < 0) {
+			con->error_msg = "bad authorize reply";
+			return ret;
+		}
+	}
+
 	switch (con->in_reply.tag) {
 	case CEPH_MSGR_TAG_FEATURES:
 		pr_err("%s%lld %s feature set mismatch,"

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/libceph-verify-authorize-reply-on-connect.patch