Re: [Qemu-devel] [PATCH v3 6/7] memory-device: avoid overflows on very huge devices

[Igor Mammedov]

On Tue, 23 Oct 2018 17:23:05 +0200
David Hildenbrand <address@hidden> wrote:

> Should not be a problem right now, but it could theoretically happen
> in the future.
> 
> Signed-off-by: David Hildenbrand <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>

> ---
>  hw/mem/memory-device.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
> index 996ad1490f..8be63c8032 100644
> --- a/hw/mem/memory-device.c
> +++ b/hw/mem/memory-device.c
> @@ -85,7 +85,8 @@ static void memory_device_check_addable(MachineState *ms, 
> uint64_t size,
>  
>      /* will we exceed the total amount of memory specified */
>      memory_device_used_region_size(OBJECT(ms), &used_region_size);
> -    if (used_region_size + size > ms->maxram_size - ms->ram_size) {
> +    if (used_region_size + size < used_region_size ||
> +        used_region_size + size > ms->maxram_size - ms->ram_size) {
>          error_setg(errp, "not enough space, currently 0x%" PRIx64
>                     " in use of total space for memory devices 0x" 
> RAM_ADDR_FMT,
>                     used_region_size, ms->maxram_size - ms->ram_size);