RE: [PATCH rdma-next 5/6] RDMA/mana_ib: boundary check before installing cq callbacks

[Konstantin Taranov]

> > Add a boundary check inside mana_ib_install_cq_cb to prevent index
> > overflow.
> 
> How is this condition possible that we are getting an out of bound queue id
> from SOC?
> 

Yes, it should not happen as the HW says the upper limit on CQ_ID,
but I think it is safer to have it to dodge bugs/faulty HW.
Better safe than sorry.
You can see the same check all over the mana.ko module.


> >
> > Fixes: 2a31c5a7e0d8 ("RDMA/mana_ib: Introduce mana_ib_install_cq_cb
> > helper function")
> > Signed-off-by: Konstantin Taranov <kotaranov@xxxxxxxxxxxxx>
> > ---
> >  drivers/infiniband/hw/mana/cq.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/infiniband/hw/mana/cq.c
> > b/drivers/infiniband/hw/mana/cq.c index 6c3bb8c..8323085 100644
> > --- a/drivers/infiniband/hw/mana/cq.c
> > +++ b/drivers/infiniband/hw/mana/cq.c
> > @@ -70,6 +70,8 @@ int mana_ib_install_cq_cb(struct mana_ib_dev
> *mdev,
> > struct mana_ib_cq *cq)
> >  	struct gdma_context *gc = mdev_to_gc(mdev);
> >  	struct gdma_queue *gdma_cq;
> >
> > +	if (cq->queue.id >= gc->max_num_cqs)
> > +		return -EINVAL;
> >  	/* Create CQ table entry */
> >  	WARN_ON(gc->cq_table[cq->queue.id]);
> >  	gdma_cq = kzalloc(sizeof(*gdma_cq), GFP_KERNEL);
> > --
> > 2.43.0