Re: [PATCH] usb: mon: make mmapped memory read only

On Mon, 19 Sept 2022 at 06:25, Dmitry Vyukov dvyukov@google.com wrote:

Hi Tadeusz,

Looking at places like these: https://elixir.bootlin.com/linux/v6.0-rc5/source/drivers/infiniband/hw/qib/q... https://elixir.bootlin.com/linux/v6.0-rc5/source/drivers/infiniband/hw/mlx5/... I think we also need to remove VM_MAYWRITE, otherwise it's still possible to turn it into a writable mapping with mprotect.

It's also probably better to return an error if VM_WRITE (or VM_EXEC?) is set rather than silently fix it up.

The credit for the VM_MAYWRITE suggestion goes to the PaX Team.

Suggested-by: PaX Team pageexec@freemail.hu