Re: [PATCH v2 1/5] string.h: add array-wrappers for (v)memdup_user()

From: Philipp Stanner
Date: Mon Sep 18 2023 - 05:15:42 EST


On Sat, 2023-09-16 at 17:32 +0300, Dan Carpenter wrote:
> On Fri, Sep 08, 2023 at 09:59:40PM +0200, Philipp Stanner wrote:
> > +static inline void *memdup_array_user(const void __user *src,
> > size_t n, size_t size)
> > +{
> > +       size_t nbytes;
> > +
> > +       if (unlikely(check_mul_overflow(n, size, &nbytes)))
> > +               return ERR_PTR(-EOVERFLOW);
>
> No need for an unlikely() because check_mul_overflow() already has
> one
> inside.

ACK. I overlooked that as it was hidden in the callstack.


>   I feel like -ENOMEM is more traditional but I doubt
> anyone/userspace
> cares.

I agree with Andy here. We're not allocating, so -ENOMEM makes no sense
IMO.


P.

>
> > +
> > +       return memdup_user(src, nbytes);
> > +}
>
> regards,
> dan carpenter
>