From: zhenwei pi <[email protected]> [ Upstream commit 25c1ca6ecaba3b751d3f7ff92d5cddff3b05f8d0 ]
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 <[email protected]> Reviewed-by: Sagi Grimberg <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- drivers/nvme/host/rdma.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index a41ee9feab8e7..e957ad0a07f58 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -1520,6 +1520,14 @@ 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 -- 2.27.0
