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From:   Ilya Dryomov <idryomov@gmail.com>
Date:   Tue, 8 Jun 2021 21:07:18 +0200
Message-ID: <CAOi1vP-B4A4bmd=ZbnwqEa14BizN-X8V4ktUMWGuEtXu8n2y-g@mail.gmail.com>
Subject: Re: [PATCH 5.12 083/161] libceph: dont set global_id until we get an
 auth ticket
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     LKML <linux-kernel@vger.kernel.org>, stable@vger.kernel.org,
        Sage Weil <sage@redhat.com>, Sasha Levin <sashal@kernel.org>
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On Tue, Jun 8, 2021 at 8:48 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> From: Ilya Dryomov <idryomov@gmail.com>
>
> [ Upstream commit 61ca49a9105faefa003b37542cebad8722f8ae22 ]
>
> With the introduction of enforcing mode, setting global_id as soon
> as we get it in the first MAuth reply will result in EACCES if the
> connection is reset before we get the second MAuth reply containing
> an auth ticket -- because on retry we would attempt to reclaim that
> global_id with no auth ticket at hand.
>
> Neither ceph_auth_client nor ceph_mon_client depend on global_id
> being set ealy, so just delay the setting until we get and process
> the second MAuth reply.  While at it, complain if the monitor sends
> a zero global_id or changes our global_id as the session is likely
> to fail after that.
>
> Cc: stable@vger.kernel.org # needs backporting for < 5.11
> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
> Reviewed-by: Sage Weil <sage@redhat.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  net/ceph/auth.c | 36 +++++++++++++++++++++++-------------
>  1 file changed, 23 insertions(+), 13 deletions(-)
>
> diff --git a/net/ceph/auth.c b/net/ceph/auth.c
> index eb261aa5fe18..de407e8feb97 100644
> --- a/net/ceph/auth.c
> +++ b/net/ceph/auth.c
> @@ -36,6 +36,20 @@ static int init_protocol(struct ceph_auth_client *ac, int proto)
>         }
>  }
>
> +static void set_global_id(struct ceph_auth_client *ac, u64 global_id)
> +{
> +       dout("%s global_id %llu\n", __func__, global_id);
> +
> +       if (!global_id)
> +               pr_err("got zero global_id\n");
> +
> +       if (ac->global_id && global_id != ac->global_id)
> +               pr_err("global_id changed from %llu to %llu\n", ac->global_id,
> +                      global_id);
> +
> +       ac->global_id = global_id;
> +}
> +
>  /*
>   * setup, teardown.
>   */
> @@ -222,11 +236,6 @@ int ceph_handle_auth_reply(struct ceph_auth_client *ac,
>
>         payload_end = payload + payload_len;
>
> -       if (global_id && ac->global_id != global_id) {
> -               dout(" set global_id %lld -> %lld\n", ac->global_id, global_id);
> -               ac->global_id = global_id;
> -       }
> -
>         if (ac->negotiating) {
>                 /* server does not support our protocols? */
>                 if (!protocol && result < 0) {
> @@ -253,11 +262,16 @@ int ceph_handle_auth_reply(struct ceph_auth_client *ac,
>
>         ret = ac->ops->handle_reply(ac, result, payload, payload_end,
>                                     NULL, NULL, NULL, NULL);
> -       if (ret == -EAGAIN)
> +       if (ret == -EAGAIN) {
>                 ret = build_request(ac, true, reply_buf, reply_len);
> -       else if (ret)
> +               goto out;
> +       } else if (ret) {
>                 pr_err("auth protocol '%s' mauth authentication failed: %d\n",
>                        ceph_auth_proto_name(ac->protocol), result);
> +               goto out;
> +       }
> +
> +       set_global_id(ac, global_id);
>
>  out:
>         mutex_unlock(&ac->mutex);
> @@ -484,15 +498,11 @@ int ceph_auth_handle_reply_done(struct ceph_auth_client *ac,
>         int ret;
>
>         mutex_lock(&ac->mutex);
> -       if (global_id && ac->global_id != global_id) {
> -               dout("%s global_id %llu -> %llu\n", __func__, ac->global_id,
> -                    global_id);
> -               ac->global_id = global_id;
> -       }
> -
>         ret = ac->ops->handle_reply(ac, 0, reply, reply + reply_len,
>                                     session_key, session_key_len,
>                                     con_secret, con_secret_len);
> +       if (!ret)
> +               set_global_id(ac, global_id);
>         mutex_unlock(&ac->mutex);
>         return ret;
>  }

Hi Greg,

I asked Sasha to drop this patch earlier today.

Thanks,

                Ilya