Re: [PATCH] net/failsafe: Fix crash due to in-valid sub-device port id

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 7 Dec 2022 17:21:42 +0000
Ferruh Yigit <ferruh.yigit@amd.com> wrote:

> On 11/16/2022 12:11 PM, madhuker.mythri@oracle.com wrote:
> > From: Madhuker Mythri <madhuker.mythri@oracle.com>
> > 
> > Crash occurring while the DPDK secondary processes trying to probe the
> > tap-device, where tap-device is a sub-device of Fail-safe device.
> > Some-times we get in-valid sub-devices(with the in-valid port-id's),
> > due to which the IPC communication does not get response and causes the
> > communication failures b/w primary/secondary process.

Fix the underlying communication issue. If there is no response then
the code is continuing on in an invalid state. Lots more will likely
break.

> > So, need to validate the sub-device(tap) while secondary process probe in
> > the Fail-safe PMD, to avoid such issues.
> > 
> > Bugzilla Id: 1116
> > 
> > Signed-off-by: Madhuker Mythri <madhuker.mythri@oracle.com>
> > ---
> >  drivers/net/failsafe/failsafe.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/net/failsafe/failsafe.c b/drivers/net/failsafe/failsafe.c
> > index 32811403b4..51d4440ac7 100644
> > --- a/drivers/net/failsafe/failsafe.c
> > +++ b/drivers/net/failsafe/failsafe.c
> > @@ -361,6 +361,9 @@ rte_pmd_failsafe_probe(struct rte_vdev_device *vdev)
> >  			if (sdev->devargs.name[0] == '\0')
> >  				continue;
> >  
> > +			if (!rte_eth_dev_is_valid_port(PORT_ID(sdev)))
> > +				continue;
> > +  
> 
> 
> This is in the 'FOREACH_SUBDEV()' block, why an invalid subdevice
> provided by the macro?
> 
> Instead of invalid port check, should we fix the macro?
> 
> Overall I am not clear why this defect occurs, bugzilla report also
> don't have much detail.
> Can you please provide more details why this defect happens?
> 

I am going to reject this patch.