Messages in this thread | | | Subject | Re: [PATCH] nvme: fix out of bounds access in nvme_cqe_pending | From | Yao HongBo <> | Date | Thu, 10 Jan 2019 09:54:59 +0800 |
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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.
>> 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. > > . > Need i send a v2 version?
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