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authorHongbo Yao <yaohongbo@huawei.com>2019-01-07 10:22:07 +0800
committerChristoph Hellwig <hch@lst.de>2019-01-09 13:47:05 -0500
commitdcca1662727220d18fa351097ddff33f95f516c5 (patch)
treef2c10b033b953198237cc513edf5d73df9aff69b /drivers/nvme
parent8fae268b40f5191227ae7050a99cb2cf1b914ddd (diff)
downloadlinux-dcca1662727220d18fa351097ddff33f95f516c5.tar.bz2
nvme-pci: fix out of bounds access in nvme_cqe_pending
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>
Diffstat (limited to 'drivers/nvme')
-rw-r--r--drivers/nvme/host/pci.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f891eb57f263..3f53a2c3042d 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1020,9 +1020,11 @@ 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++;
}
}