WARNING: DATA RACE
Write at 0x00c00106a6c8 by goroutine 373:
  gvisor.googlesource.com/gvisor/pkg/sentry/mm.(*MemoryManager).Brk()
      pkg/sentry/mm/syscalls.go:753 +0x3e1
  gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux.Brk()
      pkg/sentry/syscalls/linux/sys_mmap.go:32 +0x77
DIAGNOSIS:
I0501 08:41:14.193582   39100 x:0] ***************************
I0501 08:41:14.193724   39100 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]
I0501 08:41:14.193804   39100 x:0] Version release-20190304.1-163-g8bfb83d0acde
I0501 08:41:14.193869   39100 x:0] PID: 39100
I0501 08:41:14.193889   39100 x:0] UID: 0, GID: 0
I0501 08:41:14.193927   39100 x:0] Configuration:
I0501 08:41:14.193943   39100 x:0] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0501 08:41:14.193984   39100 x:0] 		Platform: ptrace
I0501 08:41:14.194034   39100 x:0] 		FileAccess: shared, overlay: false
I0501 08:41:14.194063   39100 x:0] 		Network: sandbox, logging: false
I0501 08:41:14.194105   39100 x:0] 		Strace: false, max size: 1024, syscalls: []
I0501 08:41:14.194155   39100 x:0] ***************************
D0501 08:41:14.194215   39100 x:0] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:41:14.201385   39100 x:0] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-0": signal 0
D0501 08:41:14.201486   39100 x:0] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:41:14.201526   39100 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:41:14.201940   39100 x:0] urpc: successfully marshalled 117 bytes.
D0501 08:41:14.203565   39100 x:0] urpc: unmarshal success.
I0501 08:41:14.203746   39100 x:0] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0", PID: 15294
I0501 08:41:14.203810   39100 x:0] Retrieving sandbox stacks
D0501 08:41:14.203840   39100 x:0] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:41:14.203891   39100 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:41:14.204323   39100 x:0] urpc: successfully marshalled 36 bytes.
D0501 08:41:14.437892   39100 x:0] urpc: unmarshal success.
I0501 08:41:14.438005   39100 x:0]      *** Stack dump ***
goroutine 441353 [running]:
gvisor.googlesource.com/gvisor/pkg/log.Stacks(0x45c801, 0xc000358d80, 0xc0014b31a0, 0xc000bb7180)
	pkg/log/log.go:259 +0xb6
gvisor.googlesource.com/gvisor/runsc/boot.(*debug).Stacks(0x2427e60, 0x2427e60, 0xc00035a3b0, 0x0, 0x0)
	runsc/boot/debug.go:26 +0x38
reflect.Value.call(0xc000358d80, 0xc0003701c0, 0x13, 0x115a58b, 0x4, 0xc00129feb8, 0x3, 0x3, 0x4a864e, 0x10074e0, ...)
	GOROOT/src/reflect/value.go:447 +0x649
reflect.Value.Call(0xc000358d80, 0xc0003701c0, 0x13, 0xc00129feb8, 0x3, 0x3, 0x0, 0x2427e60, 0x16)
	GOROOT/src/reflect/value.go:308 +0xc1
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).handleOne(0xc00036e090, 0xc000cce330, 0x0, 0x0)
	pkg/urpc/urpc.go:325 +0x63f
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).handleRegistered(0xc00036e090, 0xc000cce330, 0xc00036e090, 0xc000cce330)
	pkg/urpc/urpc.go:420 +0x43
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).StartHandling.func1(0xc00036e090, 0xc000cce330)
	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, 3 minutes]:
sync.runtime_Semacquire(0xc0002d6214)
	GOROOT/src/runtime/sema.go:56 +0x39
sync.(*WaitGroup).Wait(0xc0002d6214)
	GOROOT/src/sync/waitgroup.go:130 +0xb2
gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Kernel).WaitExited(...)
	pkg/sentry/kernel/kernel.go:896
gvisor.googlesource.com/gvisor/runsc/boot.(*Loader).WaitExit(0xc0002ce140, 0x0, 0x0)
	runsc/boot/loader.go:785 +0x74
gvisor.googlesource.com/gvisor/runsc/cmd.(*Boot).Execute(0xc00027a120, 0x12f0300, 0xc000148010, 0xc0002802a0, 0xc0002386e0, 0x2, 0x2, 0x0)
	runsc/cmd/boot.go:252 +0x12e4
github.com/google/subcommands.(*Commander).Execute(0xc000154000, 0x12f0300, 0xc000148010, 0xc0002386e0, 0x2, 0x2, 0xc000150880)
	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:245 +0x254e