WARNING: DATA RACE
Write at 0x00c00047b448 by goroutine 332:
  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
  gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).executeSyscall()
      pkg/sentry/kernel/task_syscall.go:165 +0x407
  gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke()
      pkg/sentry/kernel/task_syscall.go:283 +0xb4
  gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter()
      pkg/sentry/kernel/task_syscall.go:244 +0x109
  gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).doSyscall()
      pkg/sentry/kernel/task_syscall.go:219 +0x1b6
  gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*runApp).execute()
      pkg/sentry/kernel/task_run.go:220 +0x18b9
  gvisor.googlesource.com/gvisor/pkg/sentry/kernel.(*Task).run()
      pkg/sentry/kernel/task_run.go:92 +0x2e5

DIAGNOSIS:
I0501 08:45:59.452263   20501 x:0] ***************************
I0501 08:45:59.452410   20501 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 08:45:59.452481   20501 x:0] Version release-20190304.1-163-g8bfb83d0acde
I0501 08:45:59.452502   20501 x:0] PID: 20501
I0501 08:45:59.452550   20501 x:0] UID: 0, GID: 0
I0501 08:45:59.452569   20501 x:0] Configuration:
I0501 08:45:59.452589   20501 x:0] 		RootDir: /syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root
I0501 08:45:59.452622   20501 x:0] 		Platform: ptrace
I0501 08:45:59.452657   20501 x:0] 		FileAccess: shared, overlay: false
I0501 08:45:59.452689   20501 x:0] 		Network: sandbox, logging: false
I0501 08:45:59.452730   20501 x:0] 		Strace: false, max size: 1024, syscalls: []
I0501 08:45:59.452776   20501 x:0] ***************************
D0501 08:45:59.452839   20501 x:0] Load container "/syzkaller/managers/ptrace-proxy-sandbox-race/workdir/gvisor_root" "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:45:59.462021   20501 x:0] Signal container "ci-gvisor-ptrace-proxy-sandbox-race-0": signal 0
D0501 08:45:59.462109   20501 x:0] Signal sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:45:59.462163   20501 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:45:59.462775   20501 x:0] urpc: successfully marshalled 117 bytes.
D0501 08:45:59.463717   20501 x:0] urpc: unmarshal success.
I0501 08:45:59.463816   20501 x:0] Found sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0", PID: 16435
I0501 08:45:59.463887   20501 x:0] Retrieving sandbox stacks
D0501 08:45:59.463906   20501 x:0] Stacks sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:45:59.463934   20501 x:0] Connecting to sandbox "ci-gvisor-ptrace-proxy-sandbox-race-0"
D0501 08:45:59.464079   20501 x:0] urpc: successfully marshalled 36 bytes.
D0501 08:45:59.575117   20501 x:0] urpc: unmarshal success.
I0501 08:45:59.575209   20501 x:0]      *** Stack dump ***
goroutine 1318 [running]:
gvisor.googlesource.com/gvisor/pkg/log.Stacks(0x45c801, 0xc0002a49c0, 0xc0004d05d0, 0xc00027ae00)
	pkg/log/log.go:259 +0xb6
gvisor.googlesource.com/gvisor/runsc/boot.(*debug).Stacks(0x2427e60, 0x2427e60, 0xc00065e0b0, 0x0, 0x0)
	runsc/boot/debug.go:26 +0x38
reflect.Value.call(0xc0002a49c0, 0xc00032c1c0, 0x13, 0x115a58b, 0x4, 0xc000907eb8, 0x3, 0x3, 0x4a864e, 0x10074e0, ...)
	GOROOT/src/reflect/value.go:447 +0x649
reflect.Value.Call(0xc0002a49c0, 0xc00032c1c0, 0x13, 0xc000907eb8, 0x3, 0x3, 0x0, 0x2427e60, 0x16)
	GOROOT/src/reflect/value.go:308 +0xc1
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).handleOne(0xc000320090, 0xc00040a480, 0x0, 0x0)
	pkg/urpc/urpc.go:325 +0x63f
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).handleRegistered(0xc000320090, 0xc00040a480, 0xc000320090, 0xc00040a480)
	pkg/urpc/urpc.go:420 +0x43
gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).StartHandling.func1(0xc000320090, 0xc00040a480)
	pkg/urpc/urpc.go:440 +0x77
created by gvisor.googlesource.com/gvisor/pkg/urpc.(*Server).StartHandling
	pkg/urpc/urpc.go:438 +0x6f