Re: [PATCH -next] scsi: libfc: Fix potential NULL pointer dereference

[Hannes Reinecke <hare@xxxxxxx>]

On 2/27/19 7:09 AM, YueHaibing wrote:
> Friendly ping:
>
> Who can review or take this, please?
>
> Thanks
>
> On 2019/1/30 18:11, YueHaibing wrote:
> > There is a potential NULL pointer dereference in case
> > fc_rport_create() fails and returns NULL.
> >
> > Fixes: 2580064b5ec6 ("scsi: libfc: Replace ->rport_create callback with function call")
> > Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
> > ---
> >   drivers/scsi/libfc/fc_lport.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
> > index ff943f4..e2a3551 100644
> > --- a/drivers/scsi/libfc/fc_lport.c
> > +++ b/drivers/scsi/libfc/fc_lport.c
> > @@ -250,6 +250,10 @@ static void fc_lport_ptp_setup(struct fc_lport *lport,
> >   	}
> >   	mutex_lock(&lport->disc.disc_mutex);
> >   	lport->ptp_rdata = fc_rport_create(lport, remote_fid);
> > +	if (!lport->ptp_rdata) {
> > +		mutex_unlock(&lport->disc.disc_mutex);
> > +		return;
> > +	}
> >   	kref_get(&lport->ptp_rdata->kref);
> >   	lport->ptp_rdata->ids.port_name = remote_wwpn;
> >   	lport->ptp_rdata->ids.node_name = remote_wwnn;
I don't think this is correct.
While it's true that fc_rport_create() might fail, fc_lport_ptp_setup() 
will still assumed to have worked by the caller.
So we should rather return an error code here from fc_lport_ptp_setup() 
and ensure it's handled properly in the caller, too.

Cheers,

Hannes