[PATCH AUTOSEL 4.9 33/34] nvmet-rdma: fix response use after free

[Sasha Levin]

From: Israel Rukshin <isra...@mellanox.com>

[ Upstream commit d7dcdf9d4e15189ecfda24cc87339a3425448d5c ]

nvmet_rdma_release_rsp() may free the response before using it at error
flow.

Fixes: 8407879 ("nvmet-rdma: fix possible bogus dereference under heavy load")
Signed-off-by: Israel Rukshin <isra...@mellanox.com>
Reviewed-by: Sagi Grimberg <s...@grimberg.me>
Reviewed-by: Max Gurtovoy <m...@mellanox.com>
Signed-off-by: Christoph Hellwig <h...@lst.de>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/nvme/target/rdma.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 2dfd877974d7..486393fa4f3e 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -524,6 +524,7 @@ static void nvmet_rdma_send_done(struct ib_cq *cq, struct 
ib_wc *wc)
 {
        struct nvmet_rdma_rsp *rsp =
                container_of(wc->wr_cqe, struct nvmet_rdma_rsp, send_cqe);
+       struct nvmet_rdma_queue *queue = cq->cq_context;
 
        nvmet_rdma_release_rsp(rsp);
 
@@ -531,7 +532,7 @@ static void nvmet_rdma_send_done(struct ib_cq *cq, struct 
ib_wc *wc)
                     wc->status != IB_WC_WR_FLUSH_ERR)) {
                pr_err("SEND for CQE 0x%p failed with status %s (%d).\n",
                        wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
-               nvmet_rdma_error_comp(rsp->queue);
+               nvmet_rdma_error_comp(queue);
        }
 }
 
-- 
2.19.1