[PATCH 4.0 137/220] iser-target: Fix possible deadlock in RDMA_CM connection error

[Greg Kroah-Hartman]

4.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sagi Grimberg <sagig@xxxxxxxxxxxx>

commit 4a579da2586bd3b79b025947ea24ede2bbfede62 upstream.

Before we reach to connection established we may get an
error event. In this case the core won't teardown this
connection (never established it), so we take care of freeing
it ourselves.

Signed-off-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/infiniband/ulp/isert/ib_isert.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -222,7 +222,7 @@ fail:
 static void
 isert_free_rx_descriptors(struct isert_conn *isert_conn)
 {
-	struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+	struct ib_device *ib_dev = isert_conn->conn_device->ib_device;
 	struct iser_rx_desc *rx_desc;
 	int i;
 
@@ -719,8 +719,8 @@ out:
 static void
 isert_connect_release(struct isert_conn *isert_conn)
 {
-	struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
 	struct isert_device *device = isert_conn->conn_device;
+	struct ib_device *ib_dev = device->ib_device;
 
 	isert_dbg("conn %p\n", isert_conn);
 
@@ -728,7 +728,8 @@ isert_connect_release(struct isert_conn
 		isert_conn_free_fastreg_pool(isert_conn);
 
 	isert_free_rx_descriptors(isert_conn);
-	rdma_destroy_id(isert_conn->conn_cm_id);
+	if (isert_conn->conn_cm_id)
+		rdma_destroy_id(isert_conn->conn_cm_id);
 
 	if (isert_conn->conn_qp) {
 		struct isert_comp *comp = isert_conn->conn_qp->recv_cq->cq_context;
@@ -878,12 +879,15 @@ isert_disconnected_handler(struct rdma_c
 	return 0;
 }
 
-static void
+static int
 isert_connect_error(struct rdma_cm_id *cma_id)
 {
 	struct isert_conn *isert_conn = cma_id->qp->qp_context;
 
+	isert_conn->conn_cm_id = NULL;
 	isert_put_conn(isert_conn);
+
+	return -1;
 }
 
 static int
@@ -912,7 +916,7 @@ isert_cma_handler(struct rdma_cm_id *cma
 	case RDMA_CM_EVENT_REJECTED:       /* FALLTHRU */
 	case RDMA_CM_EVENT_UNREACHABLE:    /* FALLTHRU */
 	case RDMA_CM_EVENT_CONNECT_ERROR:
-		isert_connect_error(cma_id);
+		ret = isert_connect_error(cma_id);
 		break;
 	default:
 		isert_err("Unhandled RDMA CMA event: %d\n", event->event);


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