From f93e91a0372c922c20d5bee260b0f43b4b8a1bee Mon Sep 17 00:00:00 2001
From: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Date: Fri, 20 May 2022 14:37:12 -0400
Subject: [PATCH 1/1] RDMA/hfi1: Fix potential integer multiplication overflow
 errors
Git-commit: f93e91a0372c922c20d5bee260b0f43b4b8a1bee
Patch-mainline: v5.19
References: git-fixes

When multiplying of different types, an overflow is possible even when
storing the result in a larger type. This is because the conversion is
done after the multiplication. So arithmetic overflow and thus in
incorrect value is possible.

Correct an instance of this in the inter packet delay calculation.  Fix by
ensuring one of the operands is u64 which will promote the other to u64 as
well ensuring no overflow.

Cc: stable@vger.kernel.org
Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Link: https://lore.kernel.org/r/20220520183712.48973.29855.stgit@awfm-01.cornelisnetworks.com
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
---
 drivers/infiniband/hw/hfi1/init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index 4436ed41547c..436372b31431 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -489,7 +489,7 @@ void set_link_ipg(struct hfi1_pportdata *ppd)
 	u16 shift, mult;
 	u64 src;
 	u32 current_egress_rate; /* Mbits /sec */
-	u32 max_pkt_time;
+	u64 max_pkt_time;
 	/*
 	 * max_pkt_time is the maximum packet egress time in units
 	 * of the fabric clock period 1/(805 MHz).
-- 
2.38.0.1.gee35aeee4b76