Re: [PATCH] nvme: fix out of bounds access in nvme_cqe_pending

[Keith Busch]

On Wed, Jan 09, 2019 at 05:54:59PM -0800, Yao HongBo wrote:
> On 1/10/2019 2:39 AM, Christoph Hellwig wrote:
> > On Mon, Jan 07, 2019 at 10:22:07AM +0800, Hongbo Yao wrote:
> >> There is an out of bounds array access in nvme_cqe_peding().
> >>
> >> When enable irq_thread for nvme interrupt, there is racing between the
> >> nvmeq->cq_head updating and reading.
> > 
> > Just curious: why did you enable this option?  Do you have a workload
> > where it matters?
> 
> Yes, there were a lot of hard interrupts reported when reading the nvme disk,
> the OS can not schedule and result in the soft lockup.so i enabled the irq_thread.

That seems a little unusual. We should be able to handle as many
interrupts as an nvme drive can send.