On 1/3/2019 12:33 PM, Raju Rangoju wrote:
Under heavy load if we don't have any pre-allocated rsps left, we dynamically allocate a rsp, but we are not actually allocating memory for nvme_completion (rsp->req.rsp). In such a case, accessing pointer fields (req->rsp->status) in nvmet_req_init() will result in crash.
To fix this, allocate the memory for nvme_completion by calling nvmet_rdma_alloc_rsp()
Fixes: 8407879c("nvmet-rdma:fix possible bogus dereference under heavy load")
Cc: stable@vger.kernel.org Reviewed-by: Max Gurtovoy maxg@mellanox.com Signed-off-by: Raju Rangoju rajur@chelsio.com
-- Changes from v1:
- Moved integer to 'if' block
- Used 'unlikely' in datapath flow condition
drivers/nvme/target/rdma.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c index a8d23eb80192..8f9e6645fcf9 100644 --- a/drivers/nvme/target/rdma.c +++ b/drivers/nvme/target/rdma.c @@ -139,6 +139,10 @@ static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc); static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc); static void nvmet_rdma_qp_event(struct ib_event *event, void *priv); static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue); +static void nvmet_rdma_free_rsp(struct nvmet_rdma_device *ndev,
struct nvmet_rdma_rsp *r);+static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev,
struct nvmet_rdma_rsp *r);static const struct nvmet_fabrics_ops nvmet_rdma_ops; @@ -182,9 +186,17 @@ nvmet_rdma_get_rsp(struct nvmet_rdma_queue *queue) spin_unlock_irqrestore(&queue->rsps_lock, flags); if (unlikely(!rsp)) {
rsp = kmalloc(sizeof(*rsp), GFP_KERNEL);
int ret = -EINVAL;
no real need to initialize ret variable (sorry I didn't see it in first review).
rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);ret = nvmet_rdma_alloc_rsp(queue->dev, rsp);if (unlikely(ret)) {kfree(rsp);return NULL;}- rsp->allocated = true; }
@@ -197,6 +209,7 @@ nvmet_rdma_put_rsp(struct nvmet_rdma_rsp *rsp) unsigned long flags; if (unlikely(rsp->allocated)) {
nvmet_rdma_free_rsp(rsp->queue->dev, rsp);