panic: runtime error: makeslice: len out of range

DIAGNOSIS:
I0319 04:12:56.381156   57580 main.go:305] ***************************
I0319 04:12:56.381338   57580 main.go:306] Args: [/syzkaller/managers/ptrace-proxy-sandbox-race/current/image -root /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root -watchdog-action=panic -network=none -debug -alsologtostderr -platform=ptrace -file-access=shared -network=sandbox -TESTONLY-unsafe-nonroot debug -stacks --ps ci-gvisor-ptrace-proxy-sandbox-race-1]
I0319 04:12:56.381613   57580 main.go:307] Version release-20200219.0-192-gfc16e64396cf
I0319 04:12:56.381703   57580 main.go:308] PID: 57580
I0319 04:12:56.382153   57580 main.go:309] UID: 0, GID: 0
I0319 04:12:56.382349   57580 main.go:310] Configuration:
I0319 04:12:56.382436   57580 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0319 04:12:56.382558   57580 main.go:312] 		Platform: ptrace
I0319 04:12:56.382641   57580 main.go:313] 		FileAccess: shared, overlay: false
I0319 04:12:56.382808   57580 main.go:314] 		Network: sandbox, logging: false
I0319 04:12:56.382939   57580 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0319 04:12:56.383041   57580 main.go:316] ***************************
W0319 04:12:56.383148   57580 main.go:321] Block the TERM signal. This is only safe in tests!
D0319 04:12:56.405025   57580 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0319 04:12:56.457017   57580 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-1": signal 0
D0319 04:12:56.459581   57580 sandbox.go:814] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0319 04:12:56.462651   57580 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0319 04:12:56.469611   57580 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0319 04:12:57.956671   57580 debug.go:128] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1", PID: 33261
I0319 04:12:57.956866   57580 debug.go:137] Retrieving sandbox stacks
D0319 04:12:57.956977   57580 sandbox.go:932] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0319 04:12:57.957108   57580 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
W0319 04:12:57.957296   57580 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 33261: connection refused
retrieving stacks: connecting to control server at PID 33261: connection refused
W0319 04:12:57.957746   57580 main.go:338] Failure to execute command, err: 1