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From:   SeongJae Park <sj@kernel.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     SeongJae Park <sj@kernel.org>, damon@lists.linux.dev,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
Subject: [PATCH 2/3] mm/damon/sysfs-schemes: handle tried regions sysfs directory allocation failure
Date:   Mon,  6 Nov 2023 23:34:07 +0000
Message-Id: <20231106233408.51159-3-sj@kernel.org>
In-Reply-To: <20231106233408.51159-1-sj@kernel.org>
References: <20231106233408.51159-1-sj@kernel.org>
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DAMOS tried regions sysfs directory allocation function
(damon_sysfs_scheme_regions_alloc()) is not handling the memory
allocation failure.  In the case, the code will dereference NULL
pointer.  Handle the failure to avoid such invalid access.

Fixes: 9277d0367ba1 ("mm/damon/sysfs-schemes: implement scheme region directory")
Cc: <stable@vger.kernel.org> # 6.2.x
Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs-schemes.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 45bd0fd4a8b1..7413cb35c5a9 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -162,6 +162,9 @@ damon_sysfs_scheme_regions_alloc(void)
 	struct damon_sysfs_scheme_regions *regions = kmalloc(sizeof(*regions),
 			GFP_KERNEL);
 
+	if (!regions)
+		return NULL;
+
 	regions->kobj = (struct kobject){};
 	INIT_LIST_HEAD(&regions->regions_list);
 	regions->nr_regions = 0;
-- 
2.34.1