Re: [patch] scsi_dh_alua: uninitialized variable in alua_rtpg()

From: Dan Carpenter
Date: Thu Apr 14 2016 - 14:21:11 EST


On Thu, Apr 14, 2016 at 08:45:18AM -0700, Bart Van Assche wrote:
> On 04/14/2016 02:39 AM, Dan Carpenter wrote:
> >It's possible to use "err" without initializing it. If it happens to be
> >a 2 which is SCSI_DH_RETRY then that could cause a bug.
> >
> >Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> >
> >diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
> >index 8eaed05..f3c994f 100644
> >--- a/drivers/scsi/device_handler/scsi_dh_alua.c
> >+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
> >@@ -513,7 +513,8 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
> > struct alua_port_group *tmp_pg;
> > int len, k, off, valid_states = 0, bufflen = ALUA_RTPG_SIZE;
> > unsigned char *desc, *buff;
> >- unsigned err, retval;
> >+ unsigned int err = 0;
> >+ unsigned int retval;
> > unsigned int tpg_desc_tbl_off;
> > unsigned char orig_transition_tmo;
> > unsigned long flags;
>
> Hello Dan,
>
> The code that uses the 'err' variable occurs in a loop. I think the
> initialization of 'err' should occur after the "retry:" label.

It looks like you're right. I'll resend. I don't know this code very
well, obviously and it's a static checker fix not something I have
tested.

regards,
dan carpenter