Re: [PATCH RFT v5 4/7] fork: Add shadow stack support to clone3()

On Sat, 2024-02-03 at 00:05 +0000, Mark Brown wrote:

+       if (args->shadow_stack) { +               addr = args->shadow_stack; +               size = args->shadow_stack_size;   -       size = adjust_shstk_size(stack_size); -       addr = alloc_shstk(0, size, 0, false); -       if (IS_ERR_VALUE(addr)) -               return addr; +               /* There should be a valid token at the top of the stack. */ +               if (!shstk_consume_token(tsk, addr + size - sizeof(u64))) +                       return (unsigned long)ERR_PTR(-EINVAL);

I think for this case, it needs: shstk->base = 0; shstk->size = 0;

To prevent trying to free the parents shadow stack when the child exits.