Re: [PATCH] block: bio-integrity: fix potential null-ptr-deref in bio_integrity_free

[Ming Lei <ming.lei@redhat.com>]

On Thu, Jun 06, 2024 at 07:52:51AM -0700, Christoph Hellwig wrote:
> On Thu, Jun 06, 2024 at 10:30:06PM +0800, Ming Lei wrote:
> > Yeah, that is one area queue freezing can't cover logical block size
> > change, but I'd suggest to put the logical bs check into submit_bio() or
> > slow path of __bio_queue_enter() at least.
> 
> We really need an alignment check in submit_bio anyway, so doing it
> under the freeze protection would also help with this.
> 
> > My concern is that nvme format is started without draining IO, and
> > IO can be submitted to hardware when nvme FW is handling formatting.
> > I am not sure if nvme FW can deal with this situation correctly.
> > Ewan suggested to run 'nvme format' with exclusive nvme disk open, which
> > needs nvme-cli change.
> 
> .. and doesn't protect against someone using a different tool anyway.
> 
> That beeing said, nvme_passthru_start actually freezes all queues
> based on the commands supported an affects log, and
> nvme_init_known_nvm_effects should force this even for controllers
> not supporting the log or reporting bogus information.  So in general
> the queue should be frozen during the actual format.

That is something I missed, thanks for sharing the story.


Thanks,
Ming