fatal error: concurrent map read and map write
DIAGNOSIS:
I0301 08:25:58.129691   49993 main.go:305] ***************************
I0301 08:25:58.129740   49993 main.go:306] Args: [/syzkaller/managers/ptrace-direct-overlay-host/current/image -root /syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root -watchdog-action=panic -network=none -debug -alsologtostderr -platform=ptrace -file-access=shared -network=host debug -stacks --ps ci-gvisor-ptrace-direct-overlay-host-0]
I0301 08:25:58.129778   49993 main.go:307] Version release-20200219.0-72-gce4d1e45bb88
I0301 08:25:58.129798   49993 main.go:308] PID: 49993
I0301 08:25:58.129819   49993 main.go:309] UID: 0, GID: 0
I0301 08:25:58.129839   49993 main.go:310] Configuration:
I0301 08:25:58.129860   49993 main.go:311] 		RootDir: /syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root
I0301 08:25:58.129891   49993 main.go:312] 		Platform: ptrace
I0301 08:25:58.129912   49993 main.go:313] 		FileAccess: shared, overlay: false
I0301 08:25:58.129941   49993 main.go:314] 		Network: host, logging: false
I0301 08:25:58.129968   49993 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0301 08:25:58.129989   49993 main.go:316] ***************************
D0301 08:25:58.130036   49993 container.go:159] Load container "/syzkaller/managers/ptrace-direct-overlay-host/workdir/gvisor_root" "ci-gvisor-ptrace-direct-overlay-host-0"
D0301 08:25:58.131572   49993 container.go:592] Signal container "ci-gvisor-ptrace-direct-overlay-host-0": signal 0
D0301 08:25:58.131604   49993 sandbox.go:806] Signal sandbox "ci-gvisor-ptrace-direct-overlay-host-0"
D0301 08:25:58.131621   49993 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-0"
D0301 08:25:58.131806   49993 urpc.go:534] urpc: successfully marshalled 118 bytes.
I0301 08:25:58.272484   49993 debug.go:122] Found sandbox "ci-gvisor-ptrace-direct-overlay-host-0", PID: 46884
I0301 08:25:58.272540   49993 debug.go:131] Retrieving sandbox stacks
D0301 08:25:58.272568   49993 sandbox.go:924] Stacks sandbox "ci-gvisor-ptrace-direct-overlay-host-0"
D0301 08:25:58.272585   49993 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-direct-overlay-host-0"
W0301 08:25:58.272638   49993 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 46884: connection refused
retrieving stacks: connecting to control server at PID 46884: connection refused
W0301 08:25:58.272765   49993 main.go:338] Failure to execute command, err: 1