Re: [PATCH] iwlwifi: d3: use struct_size() in kzalloc()

[Joe Perches]

On Thu, 2018-08-23 at 20:03 -0700, Kees Cook wrote:
> On Thu, Aug 23, 2018 at 6:15 PM, Gustavo A. R. Silva
> <gustavo@xxxxxxxxxxxxxx> wrote:
> > One of the more common cases of allocation size calculations is finding
> > the size of a structure that has a zero-sized array at the end, along
> > with memory for some number of elements for that array. For example:
> > 
> > struct foo {
> >         int stuff;
> >         void *entry[];
> > };

Question for Gustavo.

Did you find any existing instances that are miscalculated?

I believe there are some cases like:

	size = sizeof(struct foo) + count * sizeof(something);
	ptr = kmalloc(size);
	memset(ptr + sizeof(struct foo), 0, size - sizeof(struct foo));

where something could go wrong and not be detected.