WARNING: DATA RACE
Read at 0x00c004c42d90 by goroutine 1297:
  gvisor.dev/gvisor/pkg/tcpip/stack.(*TransportEndpointInfo).AddrNetProto()
      pkg/tcpip/stack/stack.go:573 +0x79
  gvisor.dev/gvisor/pkg/tcpip/transport/udp.(*endpoint).checkV4Mapped()
      pkg/tcpip/transport/udp/endpoint.go:931 +0xee
  gvisor.dev/gvisor/pkg/tcpip/transport/udp.(*endpoint).Connect()
      pkg/tcpip/transport/udp/endpoint.go:984 +0x6c
  gvisor.dev/gvisor/pkg/sentry/socket/netstack.(*SocketOperations).Connect()
      pkg/sentry/socket/netstack/netstack.go:698 +0x4c5
  gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Connect()
      pkg/sentry/syscalls/linux/sys_socket.go:280 +0x251
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall()
      pkg/sentry/kernel/task_syscall.go:170 +0x44d
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke()
      pkg/sentry/kernel/task_syscall.go:291 +0xb4
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter()
      pkg/sentry/kernel/task_syscall.go:252 +0x109
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall()
      pkg/sentry/kernel/task_syscall.go:227 +0x1b3
  gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute()
      pkg/sentry/kernel/task_run.go:232 +0x1aaa
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run()
      pkg/sentry/kernel/task_run.go:92 +0x320

Previous write at 0x00c004c42d90 by goroutine 1349:
  gvisor.dev/gvisor/pkg/tcpip/transport/udp.(*endpoint).bindLocked()
      pkg/tcpip/transport/udp/endpoint.go:1176 +0x27c
DIAGNOSIS:
I0301 15:52:55.048945   52933 main.go:305] ***************************
I0301 15:52:55.049116   52933 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]
I0301 15:52:55.049337   52933 main.go:307] Version release-20200219.0-72-gce4d1e45bb88
I0301 15:52:55.049430   52933 main.go:308] PID: 52933
I0301 15:52:55.049577   52933 main.go:309] UID: 0, GID: 0
I0301 15:52:55.049699   52933 main.go:310] Configuration:
I0301 15:52:55.049798   52933 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0301 15:52:55.049935   52933 main.go:312] 		Platform: ptrace
I0301 15:52:55.050078   52933 main.go:313] 		FileAccess: shared, overlay: false
I0301 15:52:55.050210   52933 main.go:314] 		Network: sandbox, logging: false
I0301 15:52:55.050316   52933 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0301 15:52:55.050393   52933 main.go:316] ***************************
W0301 15:52:55.050475   52933 main.go:321] Block the TERM signal. This is only safe in tests!
D0301 15:52:55.050670   52933 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0301 15:52:55.062047   52933 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-3": signal 0
D0301 15:52:55.062192   52933 sandbox.go:806] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0301 15:52:55.062326   52933 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0301 15:52:55.062801   52933 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0301 15:52:56.730203   52933 debug.go:122] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3", PID: 38013
I0301 15:52:56.730332   52933 debug.go:131] Retrieving sandbox stacks
D0301 15:52:56.730444   52933 sandbox.go:924] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
D0301 15:52:56.730548   52933 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-3"
W0301 15:52:56.730753   52933 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 38013: connection refused
retrieving stacks: connecting to control server at PID 38013: connection refused
W0301 15:52:56.731161   52933 main.go:338] Failure to execute command, err: 1