AMF/NSSF crash about free5gc HOT 8 CLOSED

diff --git a/config/nssfcfg.conf b/config/nssfcfg.conf
index b166eb8..4f3eb83 100644
--- a/config/nssfcfg.conf
+++ b/config/nssfcfg.conf
@@ -67,12 +67,6 @@ configuration:
       nsiInformationList:
         - nrfId: http://localhost:29510/nnrf-nfm/v1/nf-instances
           nsiId: 21
-    - snssai:
-        sst: 1
-        sd: 010203
-      nsiInformationList:
-        - nrfId: http://localhost:29510/nnrf-nfm/v1/nf-instances
-          nsiId: 22
   amfSetList:
     - amfSetId: 1
       amfList:

2020/08/25 09:47:52 map[$and:[map[nfType:NSSF] map[$or:[map[allowedNfTypes:AMF] map[allowedNfTypes:map[$exists:false]]]]]]
[GIN] 2020/08/25 - 09:47:52 | 200 |   31.176161ms |       127.0.0.1 | GET      /nnrf-disc/v1/nf-instances?requester-nf-type=AMF&target-nf-type=NSSF
INFO[2020-08-25T09:47:52+09:00] Request received - NSSelectionGet             NSSF=nsselection
panic: invalid argument to Intn

goroutine 261 [running]:
math/rand.(*Rand).Intn(0xc0001081b0, 0x0, 0x6)
        /usr/local/go/src/math/rand/rand.go:169 +0x9c
math/rand.Intn(...)
        /usr/local/go/src/math/rand/rand.go:337
free5gc/src/nssf/producer.selectNsiInformation(...)
        /home/xxxxx/free5gc/src/nssf/producer/nsselection_for_pdu_session.go:24
free5gc/src/nssf/producer.nsselectionForPduSession(0xc0024076b0, 0xc002137b36, 0x24, 0x0, 0xc0024455e0, 0x0, 0x0, 0x0, 0x0, 0xc001eb9cf8, ...)
        /home/xxxxx/free5gc/src/nssf/producer/nsselection_for_pdu_session.go:117 +0x29b
free5gc/src/nssf/producer.NSSelectionGet(0xc001911bc0, 0xc00248dbf0)
        /home/xxxxx/free5gc/src/nssf/producer/network_slice_information_document.go:133 +0x43f
free5gc/src/nssf/handler.Handle()
        /home/xxxxx/free5gc/src/nssf/handler/handler.go:37 +0x2e1
created by free5gc/src/nssf/service.(*NSSF).Start
        /home/xxxxx/free5gc/src/nssf/service/init.go:114 +0xd1
exit status 2
FAIL    free5gc/src/test        2.647s
INFO[2020-08-25T09:47:55+09:00] /home/xxxxx/free5gc/src/upf/src/up/up_path.c:52 UpRouteTerminate() Removing APN routes  UPF=Util
INFO[2020-08-25T09:47:55+09:00] /home/xxxxx/free5gc/src/upf/src/upf_init.c:297 PacketReceiverThread() Packet receiver thread terminated  UPF=Util

diff --git a/producer/nsselection_for_pdu_session.go b/producer/nsselection_for_pdu_session.go
index 1d75b63..11a6d84 100644
--- a/producer/nsselection_for_pdu_session.go
+++ b/producer/nsselection_for_pdu_session.go
@@ -114,10 +114,12 @@ func nsselectionForPduSession(param NsselectionQueryParameter,

        nsiInformationList := util.GetNsiInformationListFromConfig(*param.SliceInfoRequestForPduSession.SNssai)

+       if len(nsiInformationList) != 0 {
                nsiInformation := selectNsiInformation(nsiInformationList)

                authorizedNetworkSliceInfo.NsiInformation = new(NsiInformation)
                *authorizedNetworkSliceInfo.NsiInformation = nsiInformation
+       }

        return http.StatusOK
}

[GIN] 2020/08/25 - 09:54:48 | 200 |     829.697μs |       127.0.0.1 | GET      /nnssf-nsselection/v1/network-slice-information?nf-id=1fcffa27-a0f3-4a12-bbbb-226389f432e9&nf-type=AMF&slice-info-request-for-pdu-session=%7B%22sNssai%22%3A%7B%22sst%22%3A1%2C%22sd%22%3A%22010203%22%7D%2C%22roamingIndication%22%3A%22NON_ROAMING%22%7D
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0xc997b0]

goroutine 12 [running]:
free5gc/src/amf/gmm.selectSmf(0xc0008ceb00, 0x144acdb, 0xb, 0xc0002519e0, 0xc001a43a40, 0x14, 0x14, 0xc0001a3a40, 0xc0017a8240, 0x12006e0, ...)
        /home/xxxxx/free5gc/src/amf/gmm/handler.go:319 +0x290
free5gc/src/amf/gmm.HandlePDUSessionEstablishmentRequest(0xc0008ceb00, 0x144acdb, 0xb, 0xc001a43a40, 0x14, 0x14, 0xa, 0x145543d, 0xf, 0xc002cfda60, ...)
        /home/xxxxx/free5gc/src/amf/gmm/handler.go:170 +0x18d
free5gc/src/amf/gmm.HandleULNASTransport(0xc0008ceb00, 0x144acdb, 0xb, 0x2e, 0xc0017deea0, 0xc001892d02, 0x30, 0x30)
        /home/xxxxx/free5gc/src/amf/gmm/handler.go:89 +0x48b
free5gc/src/amf/gmm.register_event_3gpp(0xc00220db40, 0x144af6f, 0xb, 0xc0017a8ae0, 0x13c5e00, 0xc001892d80)
        /home/xxxxx/free5gc/src/amf/gmm/sm.go:40 +0x718
free5gc/src/amf/gmm.Registered_3gpp(0xc00220db40, 0x144af6f, 0xb, 0xc0017a8ae0, 0xc0022214e0, 0x17337d0)
        /home/xxxxx/free5gc/src/amf/gmm/sm.go:24 +0x49
free5gc/lib/fsm.(*FSM).SendEvent(...)
        /home/xxxxx/free5gc/lib/fsm/fsm.go:57
free5gc/src/amf/nas.Dispatch(0xc0008ceb00, 0x144acdb, 0xb, 0x2e, 0xc002cfd900, 0x2e, 0x39)
        /home/xxxxx/free5gc/src/amf/nas/dispatch.go:19 +0x2b5
free5gc/src/amf/nas.HandleNAS(0xc001d07680, 0x2e, 0xc001a62400, 0x35, 0x40)
        /home/xxxxx/free5gc/src/amf/nas/handler.go:41 +0x11a
free5gc/src/amf/ngap.HandleUplinkNasTransport(0xc0008669a0, 0xc002cfc6a0)
        /home/xxxxx/free5gc/src/amf/ngap/handler.go:239 +0x731
free5gc/src/amf/ngap.Dispatch(0xc001d503f0, 0xe, 0xc002efc000, 0x60, 0x2000)
        /home/xxxxx/free5gc/src/amf/ngap/dispatcher.go:45 +0x51a
free5gc/src/amf/handler.Handle()
        /home/xxxxx/free5gc/src/amf/handler/handler.go:35 +0x1db
created by free5gc/src/amf/service.(*AMF).Start
        /home/xxxxx/free5gc/src/amf/service/amf_init.go:150 +0x518
exit status 2
FAIL    free5gc/src/test        2.522s
INFO[2020-08-25T09:54:51+09:00] /home/xxxxx/free5gc/src/upf/src/up/up_path.c:52 UpRouteTerminate() Removing APN routes  UPF=Util
INFO[2020-08-25T09:54:51+09:00] /home/xxxxx/free5gc/src/upf/src/upf_init.c:297 PacketReceiverThread() Packet receiver thread terminated  UPF=Util

diff --git a/gmm/handler.go b/gmm/handler.go
index e700ba7..391a241 100644
--- a/gmm/handler.go
+++ b/gmm/handler.go
@@ -316,6 +316,10 @@ func selectSmf(ue *context.AmfUe, anType models.AccessType, pduSession *models.P
                }
        }

+       if nsiInformation == nil {
+               pduSession.NsInstance = ""
+               logger.GmmLog.Errorf("nsiInformation is still nil, use default NRF[%s]", nrfUri)
+       } else {
                pduSession.NsInstance = nsiInformation.NsiId
                nrfApiUrl, err := url.Parse(nsiInformation.NrfId)
                if err != nil {
@@ -323,6 +327,7 @@ func selectSmf(ue *context.AmfUe, anType models.AccessType, pduSession *models.P
                } else {
                        nrfUri = fmt.Sprintf("%s://%s", nrfApiUrl.Scheme, nrfApiUrl.Host)
                }
+       }

        param := Nnrf_NFDiscovery.SearchNFInstancesParamOpts{
                ServiceNames: optional.NewInterface([]models.ServiceName{models.ServiceName_NSMF_PDUSESSION}),