[PATCH rdma-next] RDMA/ucma: Protect kernel from QPN larger than declared in IBTA

[Leon Romanovsky <leon@kernel.org>]

From: Leon Romanovsky <leonro@mellanox.com>

IBTA declares QPN as 24bits, mask input to ensure that kernel
doesn't get higher bits.

Fixes: 75216638572f ("RDMA/cma: Export rdma cm interface to userspace")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
 * Not fully tested yet, passed sanity tests for now.
---
 drivers/infiniband/core/ucma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 0274e9b704be..57e68491a2fd 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -1045,7 +1045,7 @@ static void ucma_copy_conn_param(struct rdma_cm_id *id,
 	dst->retry_count = src->retry_count;
 	dst->rnr_retry_count = src->rnr_retry_count;
 	dst->srq = src->srq;
-	dst->qp_num = src->qp_num;
+	dst->qp_num = src->qp_num & 0xFFFFFF;
 	dst->qkey = (id->route.addr.src_addr.ss_family == AF_IB) ? src->qkey : 0;
 }

--
2.20.1