Re: [PATCH] nvme/rdma: Fix a use after free in nvmet_rdma_write_data_done

[Sagi Grimberg]

In nvmet_rdma_write_data_done, rsp is recoverd by wc->wr_cqe
and freed by nvmet_rdma_release_rsp(). But after that, pr_info()
used the freed chunk's member object and could leak the freed
chunk address with wc->wr_cqe by computing the offset.

Signed-off-by: Lv Yunlong <lyl2...@mail.ustc.edu.cn>
---
  drivers/nvme/target/rdma.c | 5 ++---
  1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 06b6b742bb21..6c1f3ab7649c 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -802,9 +802,8 @@ static void nvmet_rdma_write_data_done(struct ib_cq *cq, 
struct ib_wc *wc)
                nvmet_req_uninit(&rsp->req);
                nvmet_rdma_release_rsp(rsp);
                if (wc->status != IB_WC_WR_FLUSH_ERR) {
-                       pr_info("RDMA WRITE for CQE 0x%p failed with status %s 
(%d).\n",
-                               wc->wr_cqe, ib_wc_status_msg(wc->status),
-                               wc->status);
+                       pr_info("RDMA WRITE for CQE failed with status %s 
(%d).\n",
+                               ib_wc_status_msg(wc->status), wc->status);

There is nothing wrong with this reference, wr_cqe is a valid reference
and I think Israel added this for some extra information that may be
useful to him.

Israel? you ok with this removed?

                        nvmet_rdma_error_comp(queue);
                }
                return;