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@xxxxxxxxxxxxxxx>
Reviewed-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
Signed-off-by: Raju Rangoju <rajur@xxxxxxxxxxx>
--
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);
if (unlikely(!rsp))
return NULL;
+ 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);
kfree(rsp);
return;
}
