Re: [PATCH v7 07/15] scsi: fnic: Add and integrate support for FDMI

[John Meneghini]

Just a note to say that these patches are important to Red Hat and we are actively engaged in back porting and testing these patches in to RHEL-9 and RHEL-10.

I think these issues that Dan has pointed out are all issues which can be addressed in a follow up patch.

/John

On 1/7/25 07:30, Dan Carpenter wrote:
> On Wed, Dec 11, 2024 at 06:03:04PM -0800, Karan Tilak Kumar wrote:
> > @@ -612,6 +615,7 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> >   	unsigned long flags;
> >   	int hwq;
> >   	char *desc, *subsys_desc;
> > +	int len;
>
> Do not introduce unnecessary levels of indirection.  Get rid of this len
> variable.
>
> >   
> >   	/*
> >   	 * Allocate SCSI Host and set up association between host,
> > @@ -646,9 +650,17 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> >   	fnic_stats_debugfs_init(fnic);
> >   
> >   	/* Find model name from PCIe subsys ID */
> > -	if (fnic_get_desc_by_devid(pdev, &desc, &subsys_desc) == 0)
> > +	if (fnic_get_desc_by_devid(pdev, &desc, &subsys_desc) == 0) {
> >   		dev_info(&fnic->pdev->dev, "Model: %s\n", subsys_desc);
> > -	else {
> > +
> > +		/* Update FDMI model */
>
> This comment adds no information.  Delete it.
>
> > +		fnic->subsys_desc_len = strlen(subsys_desc);
>
> Keep in mind that strlen() does not count the NUL-terminator.
>
> > +		len = ARRAY_SIZE(fnic->subsys_desc);
>
> Use sizeof() when you are talking about bytes or chars.  For snprintf() and
> other string functions, it's always sizeof() and never ARRAY_SIZE().
>
> > +		if (fnic->subsys_desc_len > len)
> > +			fnic->subsys_desc_len = len;
> > +		memcpy(fnic->subsys_desc, subsys_desc, fnic->subsys_desc_len);
>
> So this is an 0-14 character buffer.  If fnic->subsys_desc_len is set to 14,
> then the string is not NUL terminated.  This is how the buffer is used in
> fdls_fdmi_register_hba()
>
> 	strscpy_pad(data, fnic->subsys_desc, FNIC_FDMI_MODEL_LEN);
> 	data[FNIC_FDMI_MODEL_LEN - 1] = 0;
>
> This suggests that fnic->subsys_desc is expected to be NUL-terminated.
> However FNIC_FDMI_MODEL_LEN is 12.  So in that case the last 3 characters
> are removed.  LOL.  It's harmless but so very annoying.
>
> Also strscpy_pad() will ensure that data[FNIC_FDMI_MODEL_LEN - 1] is set
> to zero so that line could be deleted.
>
> regards,
> dan carpenter