panic: runtime error: makeslice: len out of range

DIAGNOSIS:
I0316 21:31:24.590495   53239 main.go:305] ***************************
I0316 21:31:24.590671   53239 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]
I0316 21:31:24.590957   53239 main.go:307] Version release-20200219.0-179-g52758e16e0d1
I0316 21:31:24.591051   53239 main.go:308] PID: 53239
I0316 21:31:24.591166   53239 main.go:309] UID: 0, GID: 0
I0316 21:31:24.591284   53239 main.go:310] Configuration:
I0316 21:31:24.591420   53239 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0316 21:31:24.591519   53239 main.go:312] 		Platform: ptrace
I0316 21:31:24.591633   53239 main.go:313] 		FileAccess: shared, overlay: false
I0316 21:31:24.591769   53239 main.go:314] 		Network: sandbox, logging: false
I0316 21:31:24.591888   53239 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0316 21:31:24.591981   53239 main.go:316] ***************************
W0316 21:31:24.592084   53239 main.go:321] Block the TERM signal. This is only safe in tests!
D0316 21:31:24.592377   53239 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0316 21:31:24.603727   53239 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-1": signal 0
D0316 21:31:24.603950   53239 sandbox.go:814] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0316 21:31:24.604116   53239 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0316 21:31:24.604843   53239 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0316 21:31:25.070059   53239 debug.go:128] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1", PID: 39497
I0316 21:31:25.070224   53239 debug.go:137] Retrieving sandbox stacks
D0316 21:31:25.070322   53239 sandbox.go:932] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0316 21:31:25.070443   53239 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
W0316 21:31:25.070642   53239 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 39497: connection refused
retrieving stacks: connecting to control server at PID 39497: connection refused
W0316 21:31:25.070991   53239 main.go:338] Failure to execute command, err: 1