From: zhenwei pi <pizhenwei@bytedance.com>
Date: Sun, 25 Oct 2020 19:51:24 +0800
Subject: [PATCH] nvme-rdma: handle unexpected nvme completion data length
Git-commit: 25c1ca6ecaba3b751d3f7ff92d5cddff3b05f8d0
Patch-mainline: v5.10-rc2
References: bsc#1178612
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>
Acked-by: Hannes Reinecke <hare@suse.com>
---
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 aad829a2b50d..40a0a3b6476c 100644
--- 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
--
2.16.4