From: =?UTF-8?q?H=C3=A5kon=20Bugge?= <haakon.bugge@oracle.com>
Date: Tue, 23 Nov 2021 11:06:18 +0100
Subject: RDMA/cma: Remove open coding of overflow checking for
 private_data_len
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Patch-mainline: v5.17-rc1
Git-commit: 8d0d2b0f41b1b2add8a30dbd816051a964efa497
References: git-fixes

The existing tests are a little hard to comprehend. Use
check_add_overflow() instead.

Fixes: 04ded1672402 ("RDMA/cma: Verify private data length")
Link: https://lore.kernel.org/r/1637661978-18770-1-git-send-email-haakon.bugge@oracle.com
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/core/cma.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -4033,8 +4033,7 @@ static int cma_resolve_ib_udp(struct rdm
 
 	memset(&req, 0, sizeof req);
 	offset = cma_user_data_offset(id_priv);
-	req.private_data_len = offset + conn_param->private_data_len;
-	if (req.private_data_len < conn_param->private_data_len)
+	if (check_add_overflow(offset, conn_param->private_data_len, &req.private_data_len))
 		return -EINVAL;
 
 	if (req.private_data_len) {
@@ -4093,8 +4092,7 @@ static int cma_connect_ib(struct rdma_id
 
 	memset(&req, 0, sizeof req);
 	offset = cma_user_data_offset(id_priv);
-	req.private_data_len = offset + conn_param->private_data_len;
-	if (req.private_data_len < conn_param->private_data_len)
+	if (check_add_overflow(offset, conn_param->private_data_len, &req.private_data_len))
 		return -EINVAL;
 
 	if (req.private_data_len) {