35 lines
1.0 KiB
Diff
35 lines
1.0 KiB
Diff
From 085df42259cba7863cd6ebe5cd0d8492ac5b869e Mon Sep 17 00:00:00 2001
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From: NeilBrown <neilb@suse.com>
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Date: Thu, 6 Dec 2018 10:35:41 +1100
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Subject: [RHEL7.7 PATCH 08/24] Grow: avoid overflow in compute_backup_blocks()
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With a chunk size of 16Meg and data drive count of 8,
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this calculate can easily overflow the 'int' type that
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is used for the multiplications.
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So force it to use "long" instead.
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Reported-and-tested-by: Ed Spiridonov <edo.rus@gmail.com>
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Signed-off-by: NeilBrown <neilb@suse.com>
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Signed-off-by: Jes Sorensen <jsorensen@fb.com>
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---
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Grow.c | 3 ++-
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1 file changed, 2 insertions(+), 1 deletion(-)
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diff --git a/Grow.c b/Grow.c
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index 4436a4d..76f82c0 100644
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--- a/Grow.c
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+++ b/Grow.c
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@@ -1196,7 +1196,8 @@ unsigned long compute_backup_blocks(int nchunk, int ochunk,
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/* Find GCD */
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a = GCD(a, b);
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/* LCM == product / GCD */
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- blocks = (ochunk/512) * (nchunk/512) * odata * ndata / a;
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+ blocks = (unsigned long)(ochunk/512) * (unsigned long)(nchunk/512) *
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+ odata * ndata / a;
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return blocks;
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}
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--
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2.7.5
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