RE: [PATCH v2 1/5] ramoops: use persistent_ram_free() instead of kfree() for freeing prz

From: åæäæ / IWAMATSUïNOBUHIRO
Date: Fri Jul 29 2016 - 01:58:32 EST


Hi,

> -----Original Message-----
> From: keescook@xxxxxxxxxx [mailto:keescook@xxxxxxxxxx] On Behalf Of Kees
> Cook
> Sent: Friday, July 29, 2016 4:35 AM
> To: åæäæ / IWAMATSUïNOBUHIRO
> Cc: Anton Vorontsov; Colin Cross; Tony Luck; LKML; Hiraku Toyooka; Mark
> Salyzyn; éåèå / AGUCHIïSEIJI
> Subject: Re: [PATCH v2 1/5] ramoops: use persistent_ram_free() instead of
> kfree() for freeing prz
>
> On Sun, Jul 24, 2016 at 8:56 PM, Nobuhiro Iwamatsu
> <nobuhiro.iwamatsu.kw@xxxxxxxxxxx> wrote:
> > From: Hiraku Toyooka <hiraku.toyooka.gu@xxxxxxxxxxx>
> >
> > persistent_ram_zone(=prz) structures are allocated by
> > persistent_ram_new(), which includes vmap() or ioremap(). But they are
> > currently freed by kfree(). This uses persistent_ram_free() for correct
> this asymmetry usage.
> >
> > Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@xxxxxxxxxxx>
> > Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.kw@xxxxxxxxxxx>
> > Cc: Mark Salyzyn <salyzyn@xxxxxxxxxxx>
> > Cc: Seiji Aguchi <seiji.aguchi.tr@xxxxxxxxxxx>
>
> Oh, yes, oops. I may extract this patch and get it into v4.8, since this
> is an explicit bug fix. Thanks!
>
> -Kees

Thanks. Please pickup this commit as bug fix.
And if you have a time, please review other patches in this patch series.

Best regards,
Nobuhiro

>
> > ---
> > fs/pstore/ram.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index bd9812e..22416c0
> > 100644
> > --- a/fs/pstore/ram.c
> > +++ b/fs/pstore/ram.c
> > @@ -567,11 +567,11 @@ fail_buf:
> > kfree(cxt->pstore.buf);
> > fail_clear:
> > cxt->pstore.bufsize = 0;
> > - kfree(cxt->mprz);
> > + persistent_ram_free(cxt->mprz);
> > fail_init_mprz:
> > - kfree(cxt->fprz);
> > + persistent_ram_free(cxt->fprz);
> > fail_init_fprz:
> > - kfree(cxt->cprz);
> > + persistent_ram_free(cxt->cprz);
> > fail_init_cprz:
> > ramoops_free_przs(cxt);
> > fail_out:
> > --
> > 2.8.1
> >
> >
>
>
>
> --
> Kees Cook
> Chrome OS & Brillo Security