Re: [PATCH v2] wifi: mt76: add a check of vzalloc in mt7615_coredump_work

[Kang Chen]

Hi, Lorenzo

Thanks for your suggestions.
I totally agree with you.

Best regards,
Kang Chen

On Mon, Feb 27, 2023 at 10:07 PM Lorenzo Bianconi
<lorenzo.bianconi@xxxxxxxxxx> wrote:
>
> > From: Kang Chen <void0red@xxxxxxxxx>
> >
> > vzalloc may fails, dump might be null and will cause
> > illegal address access later.
> >
> > Fixes: d2bf7959d9c0 ("mt76: mt7663: introduce coredump support")
> > Signed-off-by: Kang Chen <void0red@xxxxxxxxx>
> > ---
> > v2 -> v1: add Fixes tag
> >
> >  drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > index a95602473..73d84c301 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > @@ -2367,6 +2367,9 @@ void mt7615_coredump_work(struct work_struct *work)
> >       }
> >
> >       dump = vzalloc(MT76_CONNAC_COREDUMP_SZ);
> > +     if (!dump)
> > +             return;
> > +
> >       data = dump;
> >
> >       while (true) {
> > --
> > 2.34.1
> >
>
> revieweing the code I guess the right approach would be the one used in
> mt7921_coredump_work():
> - free pending skbs
> - not run dev_coredumpv()
>
> What do you think?
>
> Regards,
> Lorenzo