nvmet-rdma: fix null dereference under heavy load

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Raju Rangoju 2019-01-03 23:05:31 +05:30 committed by Jens Axboe
parent b1064d3e33
commit 5cbab6303b

View File

@ -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;
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;
}