[PATCH 4.9 11/47] iser-target: Fix possible use-after-free in connection establishment error

[Greg Kroah-Hartman]

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

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

From: Sagi Grimberg <sagi@xxxxxxxxxxx>

commit cd52cb26e7ead5093635e98e07e221e4df482d34 upstream.

In case we fail to establish the connection we must drain our pre-posted
login recieve work request before continuing safely with connection
teardown.

Fixes: a060b5629ab0 ("IB/core: generic RDMA READ/WRITE API")
Reported-by: Amrani, Ram <Ram.Amrani@xxxxxxxxxx>
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/infiniband/ulp/isert/ib_isert.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -747,6 +747,7 @@ isert_connect_error(struct rdma_cm_id *c
 {
 	struct isert_conn *isert_conn = cma_id->qp->qp_context;
 
+	ib_drain_qp(isert_conn->qp);
 	list_del_init(&isert_conn->node);
 	isert_conn->cm_id = NULL;
 	isert_put_conn(isert_conn);