nvme-rdma: handle unexpected nvme completion data length

Receiving a zero length message leads to the following warnings because
the CQE is processed twice:

refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 0 at lib/refcount.c:28

RIP: 0010:refcount_warn_saturate+0xd9/0xe0
Call Trace:
 <IRQ>
 nvme_rdma_recv_done+0xf3/0x280 [nvme_rdma]
 __ib_process_cq+0x76/0x150 [ib_core]
 ...

Sanity check the received data length, to avoids this.

Thanks to Chao Leng & Sagi for suggestions.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index aad829a2b50d0f9348bd819f75dd35bc53bc1a51..40a0a3b6476c36970f3c0ad54cd81c547c0c5417 100644 (file)
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1768,6 +1768,14 @@ static void nvme_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
                return;
        }
 
+       /* sanity checking for received data length */
+       if (unlikely(wc->byte_len < len)) {
+               dev_err(queue->ctrl->ctrl.device,
+                       "Unexpected nvme completion length(%d)\n", wc->byte_len);
+               nvme_rdma_error_recovery(queue->ctrl);
+               return;
+       }
+
        ib_dma_sync_single_for_cpu(ibdev, qe->dma, len, DMA_FROM_DEVICE);
        /*
         * AEN requests are special as they don't time out and can