On Fri, Mar 24, 2023 at 07:50:01AM -0600, Jeffrey Hugo wrote:
> On 3/24/2023 4:34 AM, Manivannan Sadhasivam wrote:
> > On Fri, Mar 17, 2023 at 09:14:19AM -0600, Jeffrey Hugo wrote:
> > > If the value read from the CHDBOFF and ERDBOFF registers is outside the
> > > range of the MHI register space then an invalid address might be computed
> > > which later causes a kernel panic. Range check the read value to prevent
> > > a crash due to bad data from the device.
> > >
> > > Fixes: 6cd330ae76ff ("bus: mhi: core: Add support for ringing channel/event ring doorbells")
> >
> > Please CC stable list.
>
> The stable folks have been automatically picking up everything with a fixes
> tag for years. CCing the stable list does not seem to do anything unless
> the patch needs specific backporting adjustments.
>
> Do you still want an explicit CC?
>
That was the impression I had but Greg wanted us to explicitly CC stable list
and add a hint about how deep the patch needs to be applied.
> >
> > > Signed-off-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
> > > Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@xxxxxxxxxxx>
> > > ---
> > > drivers/bus/mhi/host/init.c | 12 ++++++++++++
> > > 1 file changed, 12 insertions(+)
> > >
> > > diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
> > > index 3d779ee..ae8ebcfb 100644
> > > --- a/drivers/bus/mhi/host/init.c
> > > +++ b/drivers/bus/mhi/host/init.c
> > > @@ -516,6 +516,12 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
> > > return -EIO;
> > > }
> > > + if (val >= mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB)) {
> > > + dev_err(dev, "CHDB offset: 0x%x is out of range: 0x%zx\n",
> > > + val, mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB));
> > > + return -EINVAL;
> >
> > Isn't -ERANGE a better errno here and also in other places of the driver?
>
> I suppose that could work. This was modeled after the existing BHI (eg
> BHIOFF) range checks. You want those updated in the same change or a
> separate one?
>
That can go into a separate change.
Thanks,
Mani
> > Thanks,
> > Mani
> >
> > > + }
> > > +
> > > /* Setup wake db */
> > > mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
> > > mhi_cntrl->wake_set = false;
> > > @@ -532,6 +538,12 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
> > > return -EIO;
> > > }
> > > + if (val >= mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings)) {
> > > + dev_err(dev, "ERDB offset: 0x%x is out of range: 0x%zx\n",
> > > + val, mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings));
> > > + return -EINVAL;
> > > + }
> > > +
> > > /* Setup event db address for each ev_ring */
> > > mhi_event = mhi_cntrl->mhi_event;
> > > for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
> > > --
> > > 2.7.4
> > >
> > >
> >
>
--
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