On Thu, 7 Feb 2019, Ilya Dryomov wrote:
> 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@xxxxxxxxxxxxxxx
> Fixes: 5c056fdc5b47 ("libceph: verify authorize reply on connect")
> Link: https://tracker.ceph.com/issues/20164
> Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Reviewed-by: Sage Weil <sage@xxxxxxxxxx>
> ---
> net/ceph/messenger.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> 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;
> + }
> }
> }
>
> --
> 2.14.4
>
>
