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

[Keith Busch]

On Thu, Mar 16, 2023 at 06:11:57PM +0200, Sagi Grimberg wrote:
> > And since we're talking about this, what happens if a command is dispatched to
> > a polled queue, but has no data transfer? The nvme driver doesn't attach a bio
> > to the request in that case, so no cookie?
> 
> IIRC, initially NONE was called once, and the loop in blk_execute_rq looped
> until the completion was met.
> 
> I would assume that any other cookie other than NONE would work here,
> because the driver .poll() would be invoked at least once (maybe set
> ONESHOT as well).

As long as the cookie points to the correct hctx, then it would work.