Re: [PATCH net-next] netfilter: xt_recent: Use struct_size() in kvzalloc()

From: Pablo Neira Ayuso
Date: Mon Feb 11 2019 - 18:45:27 EST


On Thu, Feb 07, 2019 at 06:56:08PM -0600, Gustavo A. R. Silva 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[];
> };
>
> size = sizeof(struct foo) + count * sizeof(void *);
> instance = alloc(size, GFP_KERNEL)
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> size = struct_size(instance, entry, count);
> instance = alloc(size, GFP_KERNEL)
>
> Notice that, in this case, variable sz is not necessary, hence it is
> removed.
>
> This code was detected with the help of Coccinelle.

Applied, thanks.