ftp service: breaks Honeytrap when move/make/upload files/directory

[AMKuperus]

Service FTP breaks Honeytrap when trying to:

• enter a directory just created
• upload a file to directory
• edit file in directory

Tested with Filezilla and commandline ftp on RaspberryPi and as normal running Honeytrap on Arch Linux

On RaspberryPi running dietpi:

● honeytrap.service - Honeytrap
   Loaded: loaded (/lib/systemd/system/honeytrap.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2019-04-03 14:43:06 CEST; 17s ago
     Docs: https://honeytrap.io
  Process: 3303 ExecStart=/usr/bin/honeytrap --data /var/lib/honeytrap --config /etc/honeytrap.toml (code=exite
d, status=2)
 Main PID: 3303 (code=exited, status=2)

Apr 03 14:43:06 DietPi honeytrap[3303]: github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0x135a3cf8, 0x1289e
7b4, 0x1, 0x0, 0x0)
Apr 03 14:43:06 DietPi honeytrap[3303]:         /go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x2c f
p=0x20ac23e0 sp=0x20ac23c8 pc=0x494530
Apr 03 14:43:06 DietPi honeytrap[3303]: github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0x135a3cf8, 0x1289e
7b4, 0x1, 0x0, 0x0)
Apr 03 14:43:06 DietPi honeytrap[3303]:         /go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x2c f
p=0x20ac23f8 sp=0x20ac23e0 pc=0x494530
Apr 03 14:43:06 DietPi honeytrap[3303]: github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0x135a3cf8, 0x1289e
7b4, 0x1, 0x0, 0x0)
Apr 03 14:43:06 DietPi honeytrap[3303]:         /go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x2c f
p=0x20ac2410 sp=0x20ac23f8 pc=0x494530
Apr 03 14:43:06 DietPi honeytrap[3303]: github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0x135a3cf8, 0x1289e
7b4, 0x1, 0x0, 0x0)
Apr 03 14:43:06 DietPi systemd[1]: honeytrap.service: Main process exited, code=exited, status=2/INVALIDARGUMEN
T
Apr 03 14:43:06 DietPi systemd[1]: honeytrap.service: Unit entered failed state.
Apr 03 14:43:06 DietPi systemd[1]: honeytrap.service: Failed with result 'exit-code'.

[StefanGrimminck]

It is important to note that in all of the above scenario's the ChangeDir() function is called repeatedly which crashes HoneyTrap by overflowing the stack (see goroutine 116).

Last HoneyTrap log

services > ftp > category=ftp, date=2019-04-03 15:22:33.236236055 +0200 CEST m=+24.096400701, destination-ip=::1, destination-port=21, ftp.command=CWD /, ftp.sessionid=37e54404038797f4beb9, sensor=services, source-ip=::1, source-port=44130, token=bi7ql9k3cb9h60vjtg90

Error message

runtime: goroutine stack exceeds 1000000000-byte limit
fatal error: stack overflow

Relevant portion of stack strace

goroutine 116 [running]:
github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0xc0066d4048, 0xc0000b930b, 0x1, 0x0, 0x0)
	/home/stefan/go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:34 +0x62 fp=0xc02675c368 sp=0xc02675c360 pc=0x95c6b2
github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0xc0066d4048, 0xc0000b930b, 0x1, 0x0, 0x0)
	/home/stefan/go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x3f fp=0xc02675c3a0 sp=0xc02675c368 pc=0x95c68f
github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0xc0066d4048, 0xc0000b930b, 0x1, 0x0, 0x0)
	/home/stefan/go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x3f fp=0xc02675c3d8 sp=0xc02675c3a0 pc=0x95c68f
github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0xc0066d4048, 0xc0000b930b, 0x1, 0x0, 0x0)
	/home/stefan/go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x3f fp=0xc02675c410 sp=0xc02675c3d8 pc=0x95c68f
github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0xc0066d4048, 0xc0000b930b, 0x1, 0x0, 0x0)
	/home/stefan/go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x3f fp=0xc02675c448 sp=0xc02675c410 pc=0x95c68f
github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0xc0066d4048, 0xc0000b930b, 0x1, 0x0, 0x0)
	/home/stefan/go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x3f fp=0xc02675c480 sp=0xc02675c448 pc=0x95c68f
github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0xc0066d4048, 0xc0000b930b, 0x1, 0x0, 0x0)
	/home/stefan/go/src/github.com/honeytrap/honeytrap/services/ftp/ftpfs.go:36 +0x3f fp=0xc02675c4b8 sp=0xc02675c480 pc=0x95c68f
github.com/honeytrap/honeytrap/services/ftp.(*Fs).ChangeDir(0xc0066d4048, 0xc0000b930b, 0x1, 0x0, 0x0)
...additional frames elided...

[CapacitorSet]

Reported in #277 and fixed in #213 which is yet to be merged.