Re: [PATCH] proc: use vmalloc for our kernel buffer

[Josef Bacik]

On 8/13/20 10:59 AM, Matthew Wilcox wrote:
> On Thu, Aug 13, 2020 at 10:53:05AM -0400, Josef Bacik wrote:
> > +/**
> > + * vmemdup_user - duplicate memory region from user space and NUL-terminate
>
> vmemdup_user_nul()
>
> > +void *vmemdup_user_nul(const void __user *src, size_t len)
> > +{
> > +	void *p;
> > +
> > +	p = kvmalloc(len, GFP_USER);
>
> len+1, shirley?
>
> > +	if (!p)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	if (copy_from_user(p, src, len)) {
> > +		kvfree(p);
> > +		return ERR_PTR(-EFAULT);
> > +	}
>
> I think you forgot
>
>          p[len] = '\0';

Sweet lord I need more sleep, my bad.  Thanks,

Josef