iscsi_logout_sync sometimes abruptly closes socket

[sitsofe]

On macOS 10.13 I have a piece of code doing this:

[working connection that successfully does read capacity 16]
                        iscsi_set_reconnect_max_retries(ifd->iscsi, 0);
                        iscsi_set_timeout(ifd->iscsi, 3);
                        ret = iscsi_logout_sync(ifd->iscsi);

Sometimes after executing this code the iSCSI target reports this:

Jan 6 15:47:41  Login complete, TSIH 580 (1)
Jan 6 15:47:41  Connection [iqn.2010-11.libiscsi:fio:s.580.0] unexpectedly closed
Jan 6 15:47:41  Abort connection [iqn.2010-11.libiscsi:fio:s.580.0]

Setting libiscsi logging in the client reports the following:

libiscsi:2 set log level to 10 [s]
libiscsi:2 connecting to portal stut14vsa [s]
libiscsi:3 SO_KEEPALIVE set to 1 [s]
libiscsi:3 TCP_KEEPCNT set to 3 [s]
libiscsi:3 TCP_KEEPINTVL set to 30 [s]
libiscsi:3 TCP_NODELAY set to 1 [s]
libiscsi:2 connection established (10.1.3.82:53480 -> stut14vsa) [s]
libiscsi:6 TargetLoginReply: TargetPortalGroupTag=1 [s]
libiscsi:6 TargetLoginReply: TargetAlias=s [s]
libiscsi:6 TargetLoginReply: HeaderDigest=None [s]
libiscsi:6 TargetLoginReply: DataDigest=None [s]
libiscsi:6 TargetLoginReply: InitialR2T=Yes [s]
libiscsi:6 TargetLoginReply: ImmediateData=Yes [s]
libiscsi:6 TargetLoginReply: MaxBurstLength=262144 [s]
libiscsi:6 TargetLoginReply: FirstBurstLength=131072 [s]
libiscsi:6 TargetLoginReply: DefaultTime2Wait=0 [s]
libiscsi:6 TargetLoginReply: DefaultTime2Retain=0 [s]
libiscsi:6 TargetLoginReply: MaxOutstandingR2T=1 [s]
libiscsi:6 TargetLoginReply: ErrorRecoveryLevel=0 [s]
libiscsi:6 TargetLoginReply: IFMarker=No [s]
libiscsi:6 TargetLoginReply: OFMarker=No [s]
libiscsi:6 TargetLoginReply: MaxConnections=1 [s]
libiscsi:6 TargetLoginReply: MaxRecvDataSegmentLength=262144 [s]
libiscsi:6 TargetLoginReply: DataPDUInOrder=Yes [s]
libiscsi:6 TargetLoginReply: DataSequenceInOrder=Yes [s]
libiscsi:2 login successful [s]
io       63830 libiscsi: iscsi_url->lun=0
file     63830 libiscsi: get file size for stut14vsa/s/0
io       63830 libiscsi: iscsi=0x623000000100 lun=0
file     63830 libiscsi: LUN size=10485760 bytes
libiscsi:1 iscsi_service: POLLHUP, socket error. [s]
libiscsi:2 reconnect initiated [s]
libiscsi:2 connecting to portal stut14vsa [s]
libiscsi:3 SO_KEEPALIVE set to 1 [s]
libiscsi:3 TCP_KEEPCNT set to 3 [s]
libiscsi:3 TCP_KEEPINTVL set to 30 [s]
libiscsi:3 TCP_NODELAY set to 1 [s]
libiscsi:2 connection established (10.1.3.82:53481 -> stut14vsa) [s]
libiscsi:6 TargetLoginReply: TargetPortalGroupTag=1 [s]
libiscsi:6 TargetLoginReply: TargetAlias=s [s]
libiscsi:6 TargetLoginReply: HeaderDigest=None [s]
libiscsi:6 TargetLoginReply: DataDigest=None [s]
libiscsi:6 TargetLoginReply: InitialR2T=Yes [s]
libiscsi:6 TargetLoginReply: ImmediateData=Yes [s]
libiscsi:6 TargetLoginReply: MaxBurstLength=262144 [s]
libiscsi:6 TargetLoginReply: FirstBurstLength=131072 [s]
libiscsi:6 TargetLoginReply: DefaultTime2Wait=0 [s]
libiscsi:6 TargetLoginReply: DefaultTime2Retain=0 [s]
libiscsi:6 TargetLoginReply: MaxOutstandingR2T=1 [s]
libiscsi:6 TargetLoginReply: ErrorRecoveryLevel=0 [s]
libiscsi:6 TargetLoginReply: IFMarker=No [s]
libiscsi:6 TargetLoginReply: OFMarker=No [s]
libiscsi:6 TargetLoginReply: MaxConnections=1 [s]
libiscsi:6 TargetLoginReply: MaxRecvDataSegmentLength=262144 [s]
libiscsi:6 TargetLoginReply: DataPDUInOrder=Yes [s]
libiscsi:6 TargetLoginReply: DataSequenceInOrder=Yes [s]
libiscsi:2 login successful [s]
libiscsi:2 reconnect was successful [s]

and iscsi_logout_sync has returned -1.

pcap file attached.

iscsi.pcap.gz