4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit dcca1662727220d18fa351097ddff33f95f516c5 ]
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.
nvmeq->cq_head is updated in nvme_update_cq_head(), if nvmeq->cq_head equals nvmeq->q_depth and before its value set to zero, nvme_cqe_pending() uses its value as an array index, the index will be out of bounds.
Signed-off-by: Hongbo Yao yaohongbo@huawei.com [hch: slight coding style update] Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/pci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 40f76b4f08fc..f46313f441ec 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++; } }