Re: [PATCH 02/10] ANDROID: binder: Clear binder and cookie when setting handle in flat binder struct

From: Martijn Coenen
Date: Mon Oct 24 2016 - 10:03:17 EST


On Mon, Oct 24, 2016 at 3:20 PM, Martijn Coenen <maco@xxxxxxxxxxx> wrote:
> From: Arve HjÃnnevÃg <arve@xxxxxxxxxxx>
>
> Prevents leaking pointers between processes
>
> Signed-off-by: Arve HjÃnnevÃg <arve@xxxxxxxxxxx>

Signed-off-by: Martijn Coenen <maco@xxxxxxxxxxx>

> ---
> drivers/android/binder.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 3681759..3c71b98 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -1584,7 +1584,9 @@ static void binder_transaction(struct binder_proc *proc,
> fp->type = BINDER_TYPE_HANDLE;
> else
> fp->type = BINDER_TYPE_WEAK_HANDLE;
> + fp->binder = 0;
> fp->handle = ref->desc;
> + fp->cookie = 0;
> binder_inc_ref(ref, fp->type == BINDER_TYPE_HANDLE,
> &thread->todo);
>
> @@ -1634,7 +1636,9 @@ static void binder_transaction(struct binder_proc *proc,
> return_error = BR_FAILED_REPLY;
> goto err_binder_get_ref_for_node_failed;
> }
> + fp->binder = 0;
> fp->handle = new_ref->desc;
> + fp->cookie = 0;
> binder_inc_ref(new_ref, fp->type == BINDER_TYPE_HANDLE, NULL);
> trace_binder_transaction_ref_to_ref(t, ref,
> new_ref);
> @@ -1688,6 +1692,7 @@ static void binder_transaction(struct binder_proc *proc,
> binder_debug(BINDER_DEBUG_TRANSACTION,
> " fd %d -> %d\n", fp->handle, target_fd);
> /* TODO: fput? */
> + fp->binder = 0;
> fp->handle = target_fd;
> } break;
>
> --
> 2.8.0.rc3.226.g39d4020
>