[PATCH 1/2] staging: vchiq: Fix bulk userdata handling

Arnd Bergmann arnd at kernel.org
Tue Jan 5 10:13:26 EST 2021


On Tue, Jan 5, 2021 at 12:53 PM Phil Elwell <phil at raspberrypi.com> wrote:
> On Tue, 5 Jan 2021 at 11:04, Dan Carpenter <dan.carpenter at oracle.com> wrote:

> >
> > Mixing __user pointers and regular pointers is dangerous and has lead to
> > security problems in this driver in the past.  But also mixing mixing
> > tokens with pointers just makes the code hard to read.  Instead of
> > undoing Arnd's work where he split the user space and kernel pointers
> > apart we should go ahead and spit it up even more.  At least add a giant
> > FIXME comment and an item in the TODO list so we don't forget to do this
> > before removing the code from staging.
>
> Those all sound like valid comments to have made against the original
> patch, but that seems to have received little attention.
>
> I'll just leave this here - perhaps Arnd has the patience to finish the job.

I don't really have an interest in this driver. I did a larger cleanup
in order to kill off copy_in_user() from the kernel, and then cleaned
it up some more for good measure, but I would hope someone
else can finish the address space mismatch.

       Arnd



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