WARNING: DATA RACE
Read at 0x00c000ee0470 by goroutine 970:
  gvisor.dev/gvisor/pkg/tcpip/transport/tcp.(*endpoint).windowCrossedACKThreshold()
      pkg/tcpip/transport/tcp/endpoint.go:1312 +0x9e
  gvisor.dev/gvisor/pkg/tcpip/transport/tcp.(*endpoint).SetSockOptInt()
      pkg/tcpip/transport/tcp/endpoint.go:1394 +0x408
  gvisor.dev/gvisor/pkg/sentry/socket/netstack.setSockOptSocket()
      pkg/sentry/socket/netstack/netstack.go:1549 +0x84c
  gvisor.dev/gvisor/pkg/sentry/socket/netstack.SetSockOpt()
      pkg/sentry/socket/netstack/netstack.go:1509 +0x1ad
  gvisor.dev/gvisor/pkg/sentry/socket/netstack.(*SocketOperations).SetSockOpt()
      pkg/sentry/socket/netstack/netstack.go:1501 +0x69d
DIAGNOSIS:
I0227 10:52:13.317360   59137 main.go:296] ***************************
I0227 10:52:13.317546   59137 main.go:297] 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-0]
I0227 10:52:13.317755   59137 main.go:298] Version release-20200219.0-47-gde0b2ebf8635
I0227 10:52:13.317882   59137 main.go:299] PID: 59137
I0227 10:52:13.317988   59137 main.go:300] UID: 0, GID: 0
I0227 10:52:13.318101   59137 main.go:301] Configuration:
I0227 10:52:13.318160   59137 main.go:302] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0227 10:52:13.318234   59137 main.go:303] 		Platform: ptrace
I0227 10:52:13.318291   59137 main.go:304] 		FileAccess: shared, overlay: false
I0227 10:52:13.318374   59137 main.go:305] 		Network: sandbox, logging: false
I0227 10:52:13.318447   59137 main.go:306] 		Strace: false, max size: 1024, syscalls: []
I0227 10:52:13.318551   59137 main.go:307] ***************************
W0227 10:52:13.318636   59137 main.go:312] Block the TERM signal. This is only safe in tests!
D0227 10:52:13.318791   59137 container.go:158] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0227 10:52:13.326500   59137 container.go:591] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-0": signal 0
D0227 10:52:13.326686   59137 sandbox.go:788] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0227 10:52:13.326780   59137 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0227 10:52:13.327248   59137 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0227 10:52:13.527465   59137 debug.go:122] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0", PID: 48823
I0227 10:52:13.527634   59137 debug.go:131] Retrieving sandbox stacks
D0227 10:52:13.527707   59137 sandbox.go:906] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0227 10:52:13.527838   59137 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
W0227 10:52:13.528045   59137 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 48823: connection refused
retrieving stacks: connecting to control server at PID 48823: connection refused
W0227 10:52:13.528362   59137 main.go:329] 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-0"]: exit status 128
I0227 10:52:13.317360   59137 main.go:296] ***************************
I0227 10:52:13.317546   59137 main.go:297] 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-0]
I0227 10:52:13.317755   59137 main.go:298] Version release-20200219.0-47-gde0b2ebf8635
I0227 10:52:13.317882   59137 main.go:299] PID: 59137
I0227 10:52:13.317988   59137 main.go:300] UID: 0, GID: 0
I0227 10:52:13.318101   59137 main.go:301] Configuration:
I0227 10:52:13.318160   59137 main.go:302] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0227 10:52:13.318234   59137 main.go:303] 		Platform: ptrace
I0227 10:52:13.318291   59137 main.go:304] 		FileAccess: shared, overlay: false
I0227 10:52:13.318374   59137 main.go:305] 		Network: sandbox, logging: false
I0227 10:52:13.318447   59137 main.go:306] 		Strace: false, max size: 1024, syscalls: []
I0227 10:52:13.318551   59137 main.go:307] ***************************
W0227 10:52:13.318636   59137 main.go:312] Block the TERM signal. This is only safe in tests!
D0227 10:52:13.318791   59137 container.go:158] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0227 10:52:13.326500   59137 container.go:591] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-0": signal 0
D0227 10:52:13.326686   59137 sandbox.go:788] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0227 10:52:13.326780   59137 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0227 10:52:13.327248   59137 urpc.go:534] urpc: successfully marshalled 117 bytes.
I0227 10:52:13.527465   59137 debug.go:122] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0", PID: 48823
I0227 10:52:13.527634   59137 debug.go:131] Retrieving sandbox stacks
D0227 10:52:13.527707   59137 sandbox.go:906] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0227 10:52:13.527838   59137 sandbox.go:318] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
W0227 10:52:13.528045   59137 error.go:48] FATAL ERROR: retrieving stacks: connecting to control server at PID 48823: connection refused
retrieving stacks: connecting to control server at PID 48823: connection refused
W0227 10:52:13.528362   59137 main.go:329] Failure to execute command, err: 1
  gvisor.dev/gvisor/pkg/sentry/syscalls/linux.SetSockOpt()
      pkg/sentry/syscalls/linux/sys_socket.go:541 +0x303
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall()
      pkg/sentry/kernel/task_syscall.go:170 +0x455
  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 +0x1aaf
  gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run()
      pkg/sentry/kernel/task_run.go:92 +0x308