WARNING: DATA RACE
Write at 0x00c0007c6048 by goroutine 334:
  gvisor.googlesource.com/gvisor/pkg/sentry/fs/tty.(*queue).WriteFromBlocks()
      pkg/sentry/fs/tty/queue.go:246 +0x2a6
  gvisor.googlesource.com/gvisor/pkg/sentry/safemem.Writer.WriteFromBlocks-fm()
      pkg/sentry/safemem/io.go:46 +0x75
  gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).withInternalMappings()
      pkg/sentry/mm/io.go:503 +0x8ac
  gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).withVecInternalMappings()
      pkg/sentry/mm/io.go:572 +0x964
  gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).CopyInTo()
      pkg/sentry/mm/io.go:309 +0x1f1
DIAGNOSIS:
I0403 02:48:47.689399   39128 x:0] ***************************
I0403 02:48:47.689569   39128 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-0]
I0403 02:48:47.689649   39128 x:0] Version release-20190304.1-71-g52a51a8e20b3
I0403 02:48:47.689724   39128 x:0] PID: 39128
I0403 02:48:47.689771   39128 x:0] UID: 0, GID: 0
I0403 02:48:47.689793   39128 x:0] Configuration:
I0403 02:48:47.689807   39128 x:0] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0403 02:48:47.689841   39128 x:0] 		Platform: ptrace
I0403 02:48:47.689888   39128 x:0] 		FileAccess: shared, overlay: false
I0403 02:48:47.689936   39128 x:0] 		Network: sandbox, logging: false
I0403 02:48:47.689964   39128 x:0] 		Strace: false, max size: 1024, syscalls: []
I0403 02:48:47.689990   39128 x:0] ***************************
D0403 02:48:47.690045   39128 x:0] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0403 02:48:47.697578   39128 x:0] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-0": signal 0
D0403 02:48:47.697666   39128 x:0] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0403 02:48:47.697704   39128 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0403 02:48:47.699350   39128 x:0] urpc: successfully marshalled 117 bytes.
D0403 02:48:47.699529   39128 x:0] urpc: unmarshal success.
I0403 02:48:47.699596   39128 x:0] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0", PID: 36483
I0403 02:48:47.699632   39128 x:0] Retrieving sandbox stacks
D0403 02:48:47.699652   39128 x:0] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0403 02:48:47.699690   39128 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0403 02:48:47.699777   39128 x:0] urpc: successfully marshalled 36 bytes.
D0403 02:48:47.782685   39128 x:0] urpc: unmarshal success.
I0403 02:48:47.782795   39128 x:0]      *** Stack dump ***
goroutine 1242 [running]:
gvisor.googlesource.com/gvisor/pkg/log.Stacks(0x45c801, 0xc0002d0cc0, 0xc00023cc60, 0xc0005fc000)
	pkg/log/log.go:259 +0xb6
gvisor.googlesource.com/gvisor/runsc/boot.(*debug).Stacks(0x23e8c70, 0x23e8c70, 0xc00012f3d0, 0x0, 0x0)
	runsc/boot/debug.go:26 +0x38
reflect.Value.call(0xc0002d0cc0, 0xc0003221c0, 0x13, 0x11357a8, 0x4, 0xc000837eb8, 0x3, 0x3, 0x4a864e, 0xfe5cc0, ...)
	GOROOT/src/reflect/value.go:447 +0x649
reflect.Value.Call(0xc0002d0cc0, 0xc0003221c0, 0x13, 0xc000837eb8, 0x3, 0x3, 0x0, 0x23e8c70, 0x16)
	GOROOT/src/reflect/value.go:308 +0xc1
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).handleOne(0xc0002b8150, 0xc0003f97a0, 0x0, 0x0)
	pkg/urpc/urpc.go:325 +0x63f
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).handleRegistered(0xc0002b8150, 0xc0003f97a0, 0xc0002b8150, 0xc0003f97a0)
	pkg/urpc/urpc.go:420 +0x43
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).StartHandling.func1(0xc0002b8150, 0xc0003f97a0)
	pkg/urpc/urpc.go:440 +0x77
created by gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).StartHandling
	pkg/urpc/urpc.go:438 +0x6f

goroutine 1 [semacquire, 1 minutes]:
sync.runtime_Semacquire(0xc0002dc0d4)
	GOROOT/src/runtime/sema.go:56 +0x39
sync.(*WaitGroup).Wait(0xc0002dc0d4)
	GOROOT/src/sync/waitgroup.go:130 +0xb2
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Kernel).WaitExited(...)
	pkg/sentry/kernel/kernel.go:820
gvisor.googlesource.com/gvisor/runsc/boot.(*Loader).WaitExit(0xc00026c8c0, 0x0, 0x0)
	runsc/boot/loader.go:781 +0x74
gvisor.googlesource.com/gvisor/runsc/cmd.(*Boot).Execute(0xc0001bc240, 0x12c7e00, 0xc000140010, 0xc000146a80, 0xc0001c90a0, 0x2, 0x2, 0x0)
	runsc/cmd/boot.go:252 +0x12e4
github.com/google/subcommands.(*Commander).Execute(0xc00014c000, 0x12c7e00, 0xc000140010, 0xc0001c90a0, 0x2, 0x2, 0x203000)
	external/com_github_google_subcommands/subcommands.go:141 +0x522
github.com/google/subcommands.Execute(...)
	external/com_github_google_subcommands/subcommands.go:371
main.main()
	runsc/main.go:238 +0x2473