[merged mm-hotfixes-stable] mm-damon-lru_sort-avoid-divide-by-zero-in-damon_lru_sort_apply_parameters.patch removed from -mm tree

[merged mm-hotfixes-stable] mm-damon-lru_sort-avoid-divide-by-zero-in-damon_lru_sort_apply_parameters.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters()
has been removed from the -mm tree.  Its filename was
     mm-damon-lru_sort-avoid-divide-by-zero-in-damon_lru_sort_apply_parameters.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Quanmin Yan <yanquanmin1@huawei.com>
Subject: mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters()
Date: Wed, 27 Aug 2025 19:58:57 +0800

Patch series "mm/damon: avoid divide-by-zero in DAMON module's parameters
application".

DAMON's RECLAIM and LRU_SORT modules perform no validation on
user-configured parameters during application, which may lead to
division-by-zero errors.

Avoid the divide-by-zero by adding validation checks when DAMON modules
attempt to apply the parameters.


This patch (of 2):

During the calculation of 'hot_thres' and 'cold_thres', either
'sample_interval' or 'aggr_interval' is used as the divisor, which may
lead to division-by-zero errors.  Fix it by directly returning -EINVAL
when such a case occurs.  Additionally, since 'aggr_interval' is already
required to be set no smaller than 'sample_interval' in damon_set_attrs(),
only the case where 'sample_interval' is zero needs to be checked.

Link: https://lkml.kernel.org/r/20250827115858.1186261-2-yanquanmin1@huawei.com
Fixes: 40e983cca927 ("mm/damon: introduce DAMON-based LRU-lists Sorting")
Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: ze zuo <zuoze1@huawei.com>
Cc: <stable@vger.kernel.org>	[6.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/lru_sort.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/mm/damon/lru_sort.c~mm-damon-lru_sort-avoid-divide-by-zero-in-damon_lru_sort_apply_parameters
+++ a/mm/damon/lru_sort.c
@@ -198,6 +198,11 @@ static int damon_lru_sort_apply_paramete
 	if (err)
 		return err;
 
+	if (!damon_lru_sort_mon_attrs.sample_interval) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	err = damon_set_attrs(ctx, &damon_lru_sort_mon_attrs);
 	if (err)
 		goto out;
_

Patches currently in -mm which might be from yanquanmin1@huawei.com are

mm-damon-add-damon_ctx-min_sz_region.patch