Don't attempt to parse JSON payload if it is 0 bytes long.

Also added a test to trigger this.
weaveworks · Apr 5, 2016 · 706c7b8 · 706c7b8
1 parent b7d49cd
commit 706c7b8
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Showing 2 changed files with 6 additions and 1 deletion.
diff --git a/proxy/start_container_interceptor.go b/proxy/start_container_interceptor.go
@@ -15,7 +15,7 @@ func (i *startContainerInterceptor) InterceptRequest(r *http.Request) error {
 
 	// If the client has sent some JSON which might be a HostConfig, add our
 	// parameters back into it, otherwise Docker will consider them overwritten
-	if containerShouldAttach(container) && r.Header.Get("Content-Type") == "application/json" {
+	if containerShouldAttach(container) && r.Header.Get("Content-Type") == "application/json" && r.ContentLength > 0 {
 		params := map[string]interface{}{}
 		if err := unmarshalRequestBody(r, &params); err != nil {
 			return err

diff --git a/test/666_abuse_of_start_test.sh b/test/666_abuse_of_start_test.sh
@@ -33,6 +33,11 @@ proxy docker_on $HOST1 create --name=c4 --memory-swap -1 $SMALL_IMAGE echo foo
 assert_raises "proxy docker_api_on $HOST1 POST /containers/c4/start 'null'"
 assert "docker_on $HOST1 inspect -f '{{.HostConfig.MemorySwap}}' c4" "-1"
 
+# Start c4b with an empty HostConfig (generated by Docker 1.11.0-rc2)
+proxy docker_on $HOST1 create --name=c4b --memory-swap -1 $SMALL_IMAGE echo foo
+assert_raises "proxy docker_api_on $HOST1 POST /containers/c4b/start ''"
+assert "docker_on $HOST1 inspect -f '{{.HostConfig.MemorySwap}}' c4b" "-1"
+
 # Start c6 with both named and unnamed HostConfig
 proxy docker_on $HOST1 create --name=c6 $SMALL_IMAGE $CHECK_ETHWE_UP
 proxy docker_api_on $HOST1 POST /containers/c6/start '{"NetworkMode": "container:c2", "HostConfig": {"NetworkMode": "container:c1"}}'