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

[Daniel Wagner]

On Tue, Mar 21, 2023 at 01:14:11PM +0200, Sagi Grimberg wrote:
> 
> > > > That is not a crash, but a WARN stack dump.
> > > 
> > > Not sure how you get to this conclusion.
> 
> bool blk_rq_is_poll(struct request *rq)
> {
>         if (!rq->mq_hctx)
>                 return false;
>         if (rq->mq_hctx->type != HCTX_TYPE_POLL)
>                 return false;
>         if (WARN_ON_ONCE(!rq->bio)) // this is the stack dump
>                 return false;
>         return true;
> }

This should trigger if rq->bio is NULL, no? Though the rq->bio
pointer is not NULL in my trace:

[   53.669844] rq ffff888106c40000 mq_hctx ffff888106247800 type 2 bio ffff88810da4e100

And I thought the would be a WARN or something simimilar, but that
might have changed and I didn't noticed.

Sorry for being so daft.