linux-kernel - [PATCH 3.16 07/63] libceph: handle an empty authorize reply

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <lsq.1578512578.424317046@decadent.org.uk>
Date:   Wed, 08 Jan 2020 19:43:05 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, Denis Kirjanov <kda@...ux-powerpc.org>,
        "Sage Weil" <sage@...hat.com>, "Ilya Dryomov" <idryomov@...il.com>
Subject: [PATCH 3.16 07/63] libceph: handle an empty authorize reply

3.16.81-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ilya Dryomov <idryomov@...il.com>

commit 0fd3fd0a9bb0b02b6435bb7070e9f7b82a23f068 upstream.

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.

Fixes: 5c056fdc5b47 ("libceph: verify authorize reply on connect")
Link: https://tracker.ceph.com/issues/20164
Signed-off-by: Ilya Dryomov <idryomov@...il.com>
Reviewed-by: Sage Weil <sage@...hat.com>
[idryomov@...il.com: backport to 4.4: extra arg, no CEPHX_V2]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 net/ceph/messenger.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1984,15 +1984,19 @@ 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) {
+		int len = le32_to_cpu(con->in_reply.authorizer_len);
+
 		/*
 		 * 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;
+		if (len) {
+			ret = con->ops->verify_authorizer_reply(con, 0);
+			if (ret < 0) {
+				con->error_msg = "bad authorize reply";
+				return ret;
+			}
 		}
 	}