panic: runtime error: makeslice: len out of range

DIAGNOSIS:
I0314 10:24:03.242067   12759 main.go:305] ***************************
I0314 10:24:03.242181   12759 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-2]
I0314 10:24:03.242372   12759 main.go:307] Version release-20200219.0-175-g829beebf0b67
I0314 10:24:03.242440   12759 main.go:308] PID: 12759
I0314 10:24:03.242523   12759 main.go:309] UID: 0, GID: 0
I0314 10:24:03.242613   12759 main.go:310] Configuration:
I0314 10:24:03.242732   12759 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0314 10:24:03.242817   12759 main.go:312] 		Platform: ptrace
I0314 10:24:03.242912   12759 main.go:313] 		FileAccess: shared, overlay: false
I0314 10:24:03.243020   12759 main.go:314] 		Network: sandbox, logging: false
I0314 10:24:03.243154   12759 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0314 10:24:03.243230   12759 main.go:316] ***************************
W0314 10:24:03.243310   12759 main.go:321] Block the TERM signal. This is only safe in tests!
D0314 10:24:03.243604   12759 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0314 10:24:03.250646   12759 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-2": signal 0
D0314 10:24:03.250809   12759 sandbox.go:814] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0314 10:24:03.250902   12759 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0314 10:24:03.251487   12759 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0314 10:24:03.397809   12759 debug.go:128] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2", PID: 9492
I0314 10:24:03.397928   12759 debug.go:137] Retrieving sandbox stacks
D0314 10:24:03.398052   12759 sandbox.go:932] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0314 10:24:03.398174   12759 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
W0314 10:24:03.398369   12759 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 9492: connection refused
retrieving stacks: connecting to control server at PID 9492: connection refused
W0314 10:24:03.398752   12759 main.go:338] Failure to execute command, err: 1