On Wed, Nov 29, 2017 at 05:20:50PM +0100, hch@xxxxxx wrote: > On Wed, Nov 29, 2017 at 04:18:30PM +0000, Bart Van Assche wrote: > > As the above patch description shows it can happen that the SCSI core calls > > get_device() after the device reference count has reached zero and before > > the memory for struct device is freed. Although the above patch looks fine > > to me, would you consider it acceptable to modify get_device() such that it > > uses kobject_get_unless_zero() instead of kobject_get()? I'm asking this > > because that change would help to reduce the complexity of the already too > > complicated SCSI core. > > I don't think we can just modify get_device, but we can add a new > get_device_unless_zero. In fact I have an open coded variant of that > in nvme, and was planning to submit one for the current merge window.. I feel like that is just delaying the real fix, shouldn't there be a bus lock somewhere on the put_device path for this bus to prevent this? thanks, greg k-h
