Re: [PATCH] consolemap: Fix a memory leaking bug in drivers/tty/vt/consolemap.c

From: Gen Zhang
Date: Wed May 22 2019 - 20:33:18 EST


On Wed, May 22, 2019 at 01:54:47PM -0700, Kees Cook wrote:
> On Wed, May 22, 2019 at 09:50:55AM +0800, Gen Zhang wrote:
> > On Tue, May 21, 2019 at 01:44:33PM -0700, Kees Cook wrote:
> > > This doesn't look safe to me: p->uni_pgdir[n] will still have a handle
> > > to the freed memory, won't it?
> > >
> > Thanks for your reply, Kees!
> > I think you are right. Maybe we should do this:
> > kfree(p1);
> > p->uni_pgdir[n] = NULL;
> > Is this correct?
>
> That's what I'm not sure about. I *think* so, from reading the code, but
> I'd love to have Greg (or someone more familiar with the code) to
> double-check this.
>
> Otherwise, yeah, this looks right. Please send a v2 and we can debate
> the correctness there, if it turns out to be wrong. :)
>
> --
> Kees Cook
Thanks for your suggestions, Kees.
I follow your guidance and work on resubmitting a patch.
Thanks
Gen