Re: [syzbot] [usb-storage?] divide error in isd200_ata_command

[Oliver Neukum]

On 26.02.24 19:13, Alan Stern wrote:

> > It oopses here:
> >
> > 		} else {
> > 			if (!id[ATA_ID_SECTORS] || !id[ATA_ID_HEADS])
> > 				goto too_early;
>
> Those two lines are debugging code you added, right?

Yes, sorry about that.

> > 			sectnum = (u8)((lba % id[ATA_ID_SECTORS]) + 1);
> > 			cylinder = (u16)(lba / (id[ATA_ID_SECTORS] *
> > 					id[ATA_ID_HEADS]));
> >
> > in isd200_scsi_to_ata() because it must not be called before isd200_get_inquiry_data()
> > has completed.
>
> It can't be; isd200_get_inquiry_data is called by isd200_Initialization
> during probe before any SCSI commands are transmitted.

So, you are concluding that the bisection is spurious because
without that patch the SCSI layer would see a capacity of zero
and not even try to read anything?

	Regards
		Oliver