linux-stable.git/net/ceph, branch v4.19.26

libceph: handle an empty authorize reply

2019-02-27T09:08:50+00:00

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.

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 
Reviewed-by: Sage Weil 
Signed-off-by: Greg Kroah-Hartman

libceph: avoid KEEPALIVE_PENDING races in ceph_con_keepalive()

2019-02-15T07:10:13+00:00

commit 4aac9228d16458cedcfd90c7fb37211cf3653ac3 upstream.

con_fault() can transition the connection into STANDBY right after
ceph_con_keepalive() clears STANDBY in clear_standby():

    libceph user thread               ceph-msgr worker

ceph_con_keepalive()
  mutex_lock(&con->mutex)
  clear_standby(con)
  mutex_unlock(&con->mutex)
                                mutex_lock(&con->mutex)
                                con_fault()
                                  ...
                                  if KEEPALIVE_PENDING isn't set
                                    set state to STANDBY
                                  ...
                                mutex_unlock(&con->mutex)
  set KEEPALIVE_PENDING
  set WRITE_PENDING

This triggers warnings in clear_standby() when either ceph_con_send()
or ceph_con_keepalive() get to clearing STANDBY next time.

I don't see a reason to condition queue_con() call on the previous
value of KEEPALIVE_PENDING, so move the setting of KEEPALIVE_PENDING
into the critical section -- unlike WRITE_PENDING, KEEPALIVE_PENDING
could have been a non-atomic flag.

Reported-by: syzbot+acdeb633f6211ccdf886@syzkaller.appspotmail.com
Signed-off-by: Ilya Dryomov 
Tested-by: Myungho Jung 
Signed-off-by: Greg Kroah-Hartman

libceph: fall back to sendmsg for slab pages

2018-11-27T15:13:11+00:00

commit 7e241f647dc7087a0401418a187f3f5b527cc690 upstream.

skb_can_coalesce() allows coalescing neighboring slab objects into
a single frag:

  return page == skb_frag_page(frag) &&
         off == frag->page_offset + skb_frag_size(frag);

ceph_tcp_sendpage() can be handed slab pages.  One example of this is
XFS: it passes down sector sized slab objects for its metadata I/O.  If
the kernel client is co-located on the OSD node, the skb may go through
loopback and pop on the receive side with the exact same set of frags.
When tcp_recvmsg() attempts to copy out such a frag, hardened usercopy
complains because the size exceeds the object's allocated size:

  usercopy: kernel memory exposure attempt detected from ffff9ba917f20a00 (kmalloc-512) (1024 bytes)

Although skb_can_coalesce() could be taught to return false if the
resulting frag would cross a slab object boundary, we already have
a fallback for non-refcounted pages.  Utilize it for slab pages too.

Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

crush: fix using plain integer as NULL warning

2018-08-13T15:55:44+00:00

Fixes the following sparse warnings:

net/ceph/crush/mapper.c:517:76: warning: Using plain integer as NULL pointer
net/ceph/crush/mapper.c:728:68: warning: Using plain integer as NULL pointer

Signed-off-by: YueHaibing 
Reviewed-by: Ilya Dryomov 
Signed-off-by: Ilya Dryomov

libceph: remove unnecessary non NULL check for request_key

2018-08-13T15:55:44+00:00

request_key never return NULL,so no need do non-NULL check.

Signed-off-by: YueHaibing 
Reviewed-by: Ilya Dryomov 
Signed-off-by: Ilya Dryomov

libceph: weaken sizeof check in ceph_x_verify_authorizer_reply()

2018-08-02T19:33:26+00:00

Allow for extending ceph_x_authorize_reply in the future.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil

libceph: check authorizer reply/challenge length before reading

2018-08-02T19:33:26+00:00

Avoid scribbling over memory if the received reply/challenge is larger
than the buffer supplied with the authorizer.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil

libceph: implement CEPHX_V2 calculation mode

2018-08-02T19:33:25+00:00

Derive the signature from the entire buffer (both AES cipher blocks)
instead of using just the first half of the first block, leaving out
data_crc entirely.

This addresses CVE-2018-1129.

Link: http://tracker.ceph.com/issues/24837
Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil

libceph: add authorizer challenge

2018-08-02T19:33:24+00:00

When a client authenticates with a service, an authorizer is sent with
a nonce to the service (ceph_x_authorize_[ab]) and the service responds
with a mutation of that nonce (ceph_x_authorize_reply).  This lets the
client verify the service is who it says it is but it doesn't protect
against a replay: someone can trivially capture the exchange and reuse
the same authorizer to authenticate themselves.

Allow the service to reject an initial authorizer with a random
challenge (ceph_x_authorize_challenge).  The client then has to respond
with an updated authorizer proving they are able to decrypt the
service's challenge and that the new authorizer was produced for this
specific connection instance.

The accepting side requires this challenge and response unconditionally
if the client side advertises they have CEPHX_V2 feature bit.

This addresses CVE-2018-1128.

Link: http://tracker.ceph.com/issues/24836
Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil

libceph: factor out encrypt_authorizer()

2018-08-02T19:33:24+00:00

Will be used for encrypting both the initial and updated authorizers.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Sage Weil