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

Jarkko Sakkinen
2023-07-10T22:03:06Z

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@inria.fr>
>
> ---
> 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@kernel.org>

BR, Jarkko