Commit 25c1ca6e authored Oct 25, 2020 by zhenwei pi Committed by Christoph Hellwig Oct 27, 2020

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>

parent 8685699c

drivers/nvme/host/rdma.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -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

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