[PATCH 6.1.y] mm/damon/tests/vaddr-kunit: handle alloc failures in damon_test_split_evenly_fail()

[PATCH 6.1.y] mm/damon/tests/vaddr-kunit: handle alloc failures in damon_test_split_evenly_fail()

[SeongJae Park]

damon_test_split_evenly_fail() is assuming all dynamic memory allocation
in it will succeed.  Those are indeed likely in the real use cases since
those allocations are too small to fail, but theoretically those could
fail.  In the case, inappropriate memory access can happen.  Fix it by
appropriately cleanup pre-allocated memory and skip the execution of the
remaining tests in the failure cases.

Link: https://lkml.kernel.org/r/20251101182021.74868-19-sj@kernel.org
Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: <stable@vger.kernel.org>	[5.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 7890e5b5bb6e386155c6e755fe70e0cdcc77f18e)
---
 mm/damon/vaddr-test.h | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
index cfb3ba80a642..996fc14d2289 100644
--- a/mm/damon/vaddr-test.h
+++ b/mm/damon/vaddr-test.h
@@ -242,7 +242,16 @@ static void damon_test_split_evenly_fail(struct kunit *test,
 		unsigned long start, unsigned long end, unsigned int nr_pieces)
 {
 	struct damon_target *t = damon_new_target();
-	struct damon_region *r = damon_new_region(start, end);
+	struct damon_region *r;
+
+	if (!t)
+		kunit_skip(test, "target alloc fail");
+
+	r = damon_new_region(start, end);
+	if (!r) {
+		damon_free_target(t);
+		kunit_skip(test, "region alloc fail");
+	}
 
 	damon_add_region(r, t);
 	KUNIT_EXPECT_EQ(test,
-- 
2.47.3