nvme-tcp: kernel NULL pointer dereference, address: 0000000000000034

[Daniel Wagner]

On Tue, Mar 21, 2023 at 12:53:29PM +0200, Sagi Grimberg wrote:
> 
> > > admin_tagset.nr_maps = 1 (only the default map, no read, no poll)
> > 
> > Indeed, that would be to easy.
> > 
> > I've just triggered a crash where we are passing in a non-null bio. Some
> > more annotation. This time I am printing from blk_rq_is_poll() and
> > we see that that is also the case where we have a valid bio but
> > want to use the poll context:
> 
> That is not a crash, but a WARN stack dump.

Not sure how you get to this conclusion.

> It is still unclear to me
> how exactly you get to poll for a bio-less request.

I don't do anything special here. The only thing which is special is that I am
testing against Linux soft target with Hannes TP8013 patches.

> See my other reply, While I removed the below warning, and allow
> bio-less request polling, I was not able to observe any bio-less
> requests actually being polled.

Unfortunatly, somehow all your inline patches receive my inbox whitespace
damaged. Takes a few minutes to patch it manually. Anyway, with your patch
the crash is gone.