Re: [PATCH 21/26] x86/sgx: use array_size

[Jarkko Sakkinen]

On Fri, 2023-06-23 at 23:14 +0200, Julia Lawall wrote:
> Use array_size to protect against multiplication overflows.
> 
> The changes were done using the following Coccinelle semantic patch:
> 
> // <smpl>
> @@
>     expression E1, E2;
>     constant C1, C2;
>     identifier alloc = {vmalloc,vzalloc};
> @@
>     
> (
>       alloc(C1 * C2,...)
> > 
>       alloc(
> -           (E1) * (E2)
> +           array_size(E1, E2)
>       ,...)
> )
> // </smpl>
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxxx>
> 
> ---
>  arch/x86/kernel/cpu/sgx/main.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
> index 166692f2d501..3a234942c586 100644
> --- a/arch/x86/kernel/cpu/sgx/main.c
> +++ b/arch/x86/kernel/cpu/sgx/main.c
> @@ -628,7 +628,8 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size,
>  	if (!section->virt_addr)
>  		return false;
>  
> -	section->pages = vmalloc(nr_pages * sizeof(struct sgx_epc_page));
> +	section->pages = vmalloc(array_size(nr_pages,
> +					    sizeof(struct sgx_epc_page)));
>  	if (!section->pages) {
>  		memunmap(section->virt_addr);
>  		return false;
> 

Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>

BR, Jarkko