nvmet-rdma: fix response use after free

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 <israelr@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 3f7971d3706d90d5fbf382072ed8d2da2ac6e8b6..583086dd9cb9a07252a46e6589ff9cc76bf99b33 100644 (file)
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -529,6 +529,7 @@ 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);
 
@@ -536,7 +537,7 @@ 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);
        }
 }