Re: [Qemu-devel] [PATCH] linux-user: check valid address in access_ok()

[Laurent Vivier]

On 08/02/2019 18:35, Rémi Denis-Courmont wrote:
> This works around the LTP crash, but there are problably better ways to
> go about it.
> 
> Signed-off-by: Rémi Denis-Courmont <address@hidden>
> Cc: <address@hidden>
> ---
>  linux-user/qemu.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-user/qemu.h b/linux-user/qemu.h
> index ef400cb78a..1d222a0cce 100644
> --- a/linux-user/qemu.h
> +++ b/linux-user/qemu.h
> @@ -457,7 +457,8 @@ extern unsigned long guest_stack_size;
>  
>  static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
>  {
> -    return page_check_range((target_ulong)addr, size,
> +    return guest_addr_valid(addr) && guest_addr_valid(addr + size) &&

I think it should be guest_addr_valid(addr + size - 1).

Except that, it looks good.

Thanks,
Laurent