panic: runtime error: makeslice: len out of range

DIAGNOSIS:
I0314 10:16:01.355891   55964 main.go:305] ***************************
I0314 10:16:01.356066   55964 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-3]
I0314 10:16:01.356282   55964 main.go:307] Version release-20200219.0-175-g829beebf0b67
I0314 10:16:01.356422   55964 main.go:308] PID: 55964
I0314 10:16:01.356544   55964 main.go:309] UID: 0, GID: 0
I0314 10:16:01.356674   55964 main.go:310] Configuration:
I0314 10:16:01.356781   55964 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0314 10:16:01.356911   55964 main.go:312] 		Platform: ptrace
I0314 10:16:01.357066   55964 main.go:313] 		FileAccess: shared, overlay: false
I0314 10:16:01.357207   55964 main.go:314] 		Network: sandbox, logging: false
I0314 10:16:01.357349   55964 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0314 10:16:01.357484   55964 main.go:316] ***************************
W0314 10:16:01.357557   55964 main.go:321] Block the TERM signal. This is only safe in tests!
D0314 10:16:01.357833   55964 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0314 10:16:01.385291   55964 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-3": signal 0
D0314 10:16:01.385526   55964 sandbox.go:814] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0314 10:16:01.386430   55964 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0314 10:16:01.389644   55964 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0314 10:16:02.566863   55964 debug.go:128] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3", PID: 38294
I0314 10:16:02.567005   55964 debug.go:137] Retrieving sandbox stacks
D0314 10:16:02.567538   55964 sandbox.go:932] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0314 10:16:02.567686   55964 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
W0314 10:16:02.567889   55964 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 38294: connection refused
retrieving stacks: connecting to control server at PID 38294: connection refused
W0314 10:16:02.568259   55964 main.go:338] Failure to execute command, err: 1