Re: [PATCH] binder: fix sender_euid type in uapi header

[Masahiro Yamada]

On Wed, Jun 1, 2022 at 10:00 AM Carlos Llamas <cmllamas@xxxxxxxxxx> wrote:
>
> The {pid,uid}_t fields of struct binder_transaction were recently
> replaced to use kernel types in commit 169adc2b6b3c ("android/binder.h:
> add linux/android/binder(fs).h to UAPI compile-test coverage").
>
> However, using __kernel_uid_t here breaks backwards compatibility in
> architectures using 16-bits for this type, since glibc and some others
> still expect a 32-bit uid_t. Instead, let's use __kernel_uid32_t which
> avoids this compatibility problem.
>
> Fixes: 169adc2b6b3c ("android/binder.h: add linux/android/binder(fs).h to UAPI compile-test coverage")
> Reported-by: Christopher Ferris <cferris@xxxxxxxxxx>
> Signed-off-by: Carlos Llamas <cmllamas@xxxxxxxxxx>
> ---

Ahhh, good catch.

Thank you for fixing this!

 Reviewed-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>


>  include/uapi/linux/android/binder.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/android/binder.h b/include/uapi/linux/android/binder.h
> index 11157fae8a8e..688bcdaeed53 100644
> --- a/include/uapi/linux/android/binder.h
> +++ b/include/uapi/linux/android/binder.h
> @@ -289,7 +289,7 @@ struct binder_transaction_data {
>         /* General information about the transaction. */
>         __u32           flags;
>         __kernel_pid_t  sender_pid;
> -       __kernel_uid_t  sender_euid;
> +       __kernel_uid32_t        sender_euid;
>         binder_size_t   data_size;      /* number of bytes of data */
>         binder_size_t   offsets_size;   /* number of bytes of offsets */
>
> --
> 2.36.1.255.ge46751e96f-goog
>


-- 
Best Regards
Masahiro Yamada