Re: [PATCH 1/1] RDMA/uverbs: Initialize cq_context appropriately

[Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Sun, 2017-08-06 at 11:08 +0300, Matan Barak wrote:
> On Tue, Aug 1, 2017 at 8:28 AM, Potnuri Bharat Teja <bharat@chelsio.c
> om> wrote:
> > Initializing cq_context with ev_queue in create_cq(), leads to NULL
> > pointer
> > dereference in ib_uverbs_comp_handler(), if application doesnot use
> > completion
> > channel. This patch fixes the cq_context initialization.
> > 
> > Fixes: 1e7710f3f65 ("IB/core: Change completion channel to use the
> > reworked")
> > Signed-off-by: Potnuri Bharat Teja <bharat-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
> > ---
> >  drivers/infiniband/core/uverbs_cmd.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/infiniband/core/uverbs_cmd.c
> > b/drivers/infiniband/core/uverbs_cmd.c
> > index 2c98533a0203..8c829522d8c4 100644
> > --- a/drivers/infiniband/core/uverbs_cmd.c
> > +++ b/drivers/infiniband/core/uverbs_cmd.c
> > @@ -1015,7 +1015,8 @@ static struct ib_ucq_object *create_cq(struct
> > ib_uverbs_file *file,
> >         cq->uobject       = &obj->uobject;
> >         cq->comp_handler  = ib_uverbs_comp_handler;
> >         cq->event_handler = ib_uverbs_cq_event_handler;
> > -       cq->cq_context    = &ev_file->ev_queue;
> > +       cq->cq_context    = (cmd->comp_channel >= 0) ?
> > +                               &ev_file->ev_queue : NULL;
> >         atomic_set(&cq->usecnt, 0);
> > 
> >         obj->uobject.object = cq;
> > --
> > 2.5.3
> > 
> 
> Nice catch, thanks.
> I would prefer:
> cq->cq_context = ev_file ? &ev_file->ev_queue : NULL;
> 
> However, this fix is fine too.
> 
> Reviewed-by: Matan Barak <matanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

I agree, I like your solution better.  Patch fixed up and applied.

-- 
Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
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