WARNING: DATA RACE
Read at 0x00c001250490 by goroutine 1475:
  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
DIAGNOSIS:
I0301 13:56:35.207070   57605 main.go:305] ***************************
I0301 13:56:35.207234   57605 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]
I0301 13:56:35.207480   57605 main.go:307] Version release-20200219.0-72-gce4d1e45bb88
I0301 13:56:35.207590   57605 main.go:308] PID: 57605
I0301 13:56:35.207719   57605 main.go:309] UID: 0, GID: 0
I0301 13:56:35.207818   57605 main.go:310] Configuration:
I0301 13:56:35.207940   57605 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0301 13:56:35.208088   57605 main.go:312] 		Platform: ptrace
I0301 13:56:35.208221   57605 main.go:313] 		FileAccess: shared, overlay: false
I0301 13:56:35.208352   57605 main.go:314] 		Network: sandbox, logging: false
I0301 13:56:35.208462   57605 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0301 13:56:35.208594   57605 main.go:316] ***************************
W0301 13:56:35.208717   57605 main.go:321] Block the TERM signal. This is only safe in tests!
D0301 13:56:35.208971   57605 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0301 13:56:35.217413   57605 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-2": signal 0
D0301 13:56:35.217676   57605 sandbox.go:806] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0301 13:56:35.217820   57605 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0301 13:56:35.218360   57605 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0301 13:56:35.665172   57605 debug.go:122] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2", PID: 27757
I0301 13:56:35.665306   57605 debug.go:131] Retrieving sandbox stacks
D0301 13:56:35.665414   57605 sandbox.go:924] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0301 13:56:35.665522   57605 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
W0301 13:56:35.665667   57605 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 27757: connection refused
retrieving stacks: connecting to control server at PID 27757: connection refused
W0301 13:56:35.666005   57605 main.go:338] Failure to execute command, err: 1


Error collecting stacks: failed to run ["/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"]: exit status 128
I0301 13:56:35.207070   57605 main.go:305] ***************************
I0301 13:56:35.207234   57605 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]
I0301 13:56:35.207480   57605 main.go:307] Version release-20200219.0-72-gce4d1e45bb88
I0301 13:56:35.207590   57605 main.go:308] PID: 57605
I0301 13:56:35.207719   57605 main.go:309] UID: 0, GID: 0
I0301 13:56:35.207818   57605 main.go:310] Configuration:
I0301 13:56:35.207940   57605 main.go:311] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0301 13:56:35.208088   57605 main.go:312] 		Platform: ptrace
I0301 13:56:35.208221   57605 main.go:313] 		FileAccess: shared, overlay: false
I0301 13:56:35.208352   57605 main.go:314] 		Network: sandbox, logging: false
I0301 13:56:35.208462   57605 main.go:315] 		Strace: false, max size: 1024, syscalls: []
I0301 13:56:35.208594   57605 main.go:316] ***************************
W0301 13:56:35.208717   57605 main.go:321] Block the TERM signal. This is only safe in tests!
D0301 13:56:35.208971   57605 container.go:159] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0301 13:56:35.217413   57605 container.go:592] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-2": signal 0
D0301 13:56:35.217676   57605 sandbox.go:806] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0301 13:56:35.217820   57605 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0301 13:56:35.218360   57605 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0301 13:56:35.665172   57605 debug.go:122] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2", PID: 27757
I0301 13:56:35.665306   57605 debug.go:131] Retrieving sandbox stacks
D0301 13:56:35.665414   57605 sandbox.go:924] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
D0301 13:56:35.665522   57605 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-2"
W0301 13:56:35.665667   57605 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 27757: connection refused
retrieving stacks: connecting to control server at PID 27757: connection refused
W0301 13:56:35.666005   57605 main.go:338] Failure to execute command, err: 1
  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