Re: [XEN v6 10/12] xen/arm: domain_build: Check if the address fits the range of physical address

[Julien Grall <julien@xxxxxxx>]

Hi,

On 28/04/2023 18:55, Ayan Kumar Halder wrote:
> handle_pci_range() and map_range_to_domain() take addr and len as uint64_t
> parameters. Then frame numbers are obtained from addr and len by right shifting
> with PAGE_SHIFT. The frame numbers are expressed using unsigned long.
>
> Now if 64-bit >> PAGE_SHIFT, the result will have 52-bits as valid. On a 32-bit
> system, 'unsigned long' is 32-bits. Thus, there is a potential loss of value
> when the result is stored as 'unsigned long'.
>
> To mitigate this issue, we check if the starting and end address can be
> contained within the range of physical address supported on the system. If not,
> then an appropriate error is returned.
>
> Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall