panic: runtime error: index out of range

goroutine 1145473 [running]:
DIAGNOSIS:
I0403 13:14:59.064470   43402 x:0] ***************************
I0403 13:14:59.064642   43402 x:0] 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 -platform=ptrace -file-access=shared -network=sandbox debug -stacks ci-gvisor-ptrace-proxy-sandbox-race-1]
I0403 13:14:59.064718   43402 x:0] Version release-20190304.1-78-gc4caccd54042
I0403 13:14:59.064782   43402 x:0] PID: 43402
I0403 13:14:59.064857   43402 x:0] UID: 0, GID: 0
I0403 13:14:59.064983   43402 x:0] Configuration:
I0403 13:14:59.065031   43402 x:0] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0403 13:14:59.065085   43402 x:0] 		Platform: ptrace
I0403 13:14:59.065147   43402 x:0] 		FileAccess: shared, overlay: false
I0403 13:14:59.065211   43402 x:0] 		Network: sandbox, logging: false
I0403 13:14:59.065270   43402 x:0] 		Strace: false, max size: 1024, syscalls: []
I0403 13:14:59.065325   43402 x:0] ***************************
D0403 13:14:59.065423   43402 x:0] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0403 13:14:59.082420   43402 x:0] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-1": signal 0
D0403 13:14:59.082561   43402 x:0] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0403 13:14:59.082633   43402 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0403 13:14:59.083011   43402 x:0] urpc: successfully marshalled 117 bytes.
I0403 13:14:59.367256   43402 x:0] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1", PID: 3833
I0403 13:14:59.367339   43402 x:0] Retrieving sandbox stacks
D0403 13:14:59.367365   43402 x:0] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
D0403 13:14:59.367396   43402 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-1"
W0403 13:14:59.367500   43402 x:0] FATAL ERROR: retrieving stacks: connecting to control server at PID 3833: connection refused
retrieving stacks: connecting to control server at PID 3833: connection refused