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From:   SeongJae Park <sj@kernel.org>
To:     akpm@linux-foundation.org
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        SeongJae Park <sj@kernel.org>
Subject: [PATCH for-mm] mm/damon/sysfs: Fix out-of-bound array access for wmark_metric_strs[]
Date:   Tue,  1 Mar 2022 18:56:19 +0000
Message-Id: <20220301185619.2904-1-sj@kernel.org>
Precedence: bulk

Commit 7a8630be880e ("mm/damon/sysfs: support DAMOS watermarks") on -mm
tree which introduced by a patch[1] titled
mm-damon-sysfs-support-damos-watermarks.patch allows out-of-bound access
to damon_sysfs_wmark_metric_strs[] array due to wrong bound check.  This
commit fixes the wrong bound check.  The issue has found by Coverity
report for linux-next.

[1] https://www.ozlabs.org/~akpm/mmotm/broken-out/mm-damon-sysfs-support-damos-watermarks.patch

Addresses-Coverity: ("Out-of-bounds read")
Fixes: 7a8630be880e ("mm/damon/sysfs: support DAMOS watermarks")
Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 32a9d21c0db5..fda2506c676f 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -266,7 +266,7 @@ static ssize_t metric_store(struct kobject *kobj, struct kobj_attribute *attr,
 			struct damon_sysfs_watermarks, kobj);
 	enum damos_wmark_metric metric;
 
-	for (metric = 0; metric <= NR_DAMOS_WMARK_METRICS; metric++) {
+	for (metric = 0; metric < NR_DAMOS_WMARK_METRICS; metric++) {
 		if (sysfs_streq(buf, damon_sysfs_wmark_metric_strs[metric])) {
 			watermarks->metric = metric;
 			return count;
-- 
2.17.1