mdadm/0003-Grow-avoid-overflow-in-compute_backup_blocks.patch

From 488555f211b2bae7f54670e6f3fc3aef14215f44 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.com>
Date: Thu, 6 Dec 2018 10:35:41 +1100
Subject: [PATCH 03/27] Grow: avoid overflow in compute_backup_blocks()

With a chunk size of 16Meg and data drive count of 8,
this calculate can easily overflow the 'int' type that
is used for the multiplications.
So force it to use "long" instead.

Reported-and-tested-by: Ed Spiridonov <edo.rus@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>
---
 Grow.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Grow.c b/Grow.c
index 4436a4d..76f82c0 100644
--- a/Grow.c
+++ b/Grow.c
@@ -1196,7 +1196,8 @@ unsigned long compute_backup_blocks(int nchunk, int ochunk,
 	/* Find GCD */
 	a = GCD(a, b);
 	/* LCM == product / GCD */
-	blocks = (ochunk/512) * (nchunk/512) * odata * ndata / a;
+	blocks = (unsigned long)(ochunk/512) * (unsigned long)(nchunk/512) *
+		odata * ndata / a;
 
 	return blocks;
 }
-- 
2.21.1 (Apple Git-122.3)