Messages in this thread | | | Date | Wed, 9 Jan 2019 19:39:20 +0100 | From | Christoph Hellwig <> | Subject | Re: [PATCH] nvme: fix out of bounds access in nvme_cqe_pending |
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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?
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c > index d668682..68375d4 100644 > --- a/drivers/nvme/host/pci.c > +++ b/drivers/nvme/host/pci.c > @@ -908,9 +908,11 @@ static void nvme_complete_cqes(struct nvme_queue *nvmeq, u16 start, u16 end) > > static inline void nvme_update_cq_head(struct nvme_queue *nvmeq) > { > - if (++nvmeq->cq_head == nvmeq->q_depth) { > + if (nvmeq->cq_head == (nvmeq->q_depth - 1)) { > nvmeq->cq_head = 0; > nvmeq->cq_phase = !nvmeq->cq_phase; > + } else { > + ++nvmeq->cq_head;
No need for the braces above, but otherwise this looks fine. I'll apply it to nvme-4.21.
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