Re: [PATCH] xen/arm: check max_init_domid validity

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Tue, 28 Feb 2023, Bertrand Marquis wrote:
> Before trying to create a dom0less guest, check that max_init_domid
> increment will generate a valid domain ID, lower than
> DOMID_FIRST_RESERVED.
> 
> Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
>  xen/arch/arm/domain_build.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index edca23b986d2..9707eb7b1bb1 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -3879,6 +3879,9 @@ void __init create_domUs(void)
>          if ( !dt_device_is_compatible(node, "xen,domain") )
>              continue;
>  
> +        if ( (max_init_domid + 1) >= DOMID_FIRST_RESERVED )
> +            panic("No more domain IDs available\n");
> +
>          if ( dt_find_property(node, "xen,static-mem", NULL) )
>              flags |= CDF_staticmem;
>  
> -- 
> 2.25.1
>