The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0fd3fd0a9bb0b02b6435bb7070e9f7b82a23f068 Mon Sep 17 00:00:00 2001

From: Ilya Dryomov idryomov@gmail.com Date: Tue, 5 Feb 2019 20:30:27 +0100 Subject: [PATCH] libceph: handle an empty authorize reply

The authorize reply can be empty, for example when the ticket used to build the authorizer is too old and TAG_BADAUTHORIZER is returned from the service. Calling ->verify_authorizer_reply() results in an attempt to decrypt and validate (somewhat) random data in au->buf (most likely the signature block from calc_signature()), which fails and ends up in con_fault_finish() with !con->auth_retry. The ticket isn't invalidated and the connection is retried again and again until a new ticket is obtained from the monitor:

libceph: osd2 192.168.122.1:6809 bad authorize reply libceph: osd2 192.168.122.1:6809 bad authorize reply libceph: osd2 192.168.122.1:6809 bad authorize reply libceph: osd2 192.168.122.1:6809 bad authorize reply

Let TAG_BADAUTHORIZER handler kick in and increment con->auth_retry.

Cc: stable@vger.kernel.org Fixes: 5c056fdc5b47 ("libceph: verify authorize reply on connect") Link: https://tracker.ceph.com/issues/20164 Signed-off-by: Ilya Dryomov idryomov@gmail.com Reviewed-by: Sage Weil sage@redhat.com

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 3661cdd927f1..7e71b0df1fbc 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -2058,6 +2058,8 @@ static int process_connect(struct ceph_connection *con) dout("process_connect on %p tag %d\n", con, (int)con->in_tag);

if (con->auth) { + int len = le32_to_cpu(con->in_reply.authorizer_len); + /* * Any connection that defines ->get_authorizer() * should also define ->add_authorizer_challenge() and @@ -2067,8 +2069,7 @@ static int process_connect(struct ceph_connection *con) */ if (con->in_reply.tag == CEPH_MSGR_TAG_CHALLENGE_AUTHORIZER) { ret = con->ops->add_authorizer_challenge( - con, con->auth->authorizer_reply_buf, - le32_to_cpu(con->in_reply.authorizer_len)); + con, con->auth->authorizer_reply_buf, len); if (ret < 0) return ret;

@@ -2078,10 +2079,12 @@ static int process_connect(struct ceph_connection *con) return 0; }

- ret = con->ops->verify_authorizer_reply(con); - if (ret < 0) { - con->error_msg = "bad authorize reply"; - return ret; + if (len) { + ret = con->ops->verify_authorizer_reply(con); + if (ret < 0) { + con->error_msg = "bad authorize reply"; + return ret; + } } }