[PATCH 5.15.y] mm/damon/tests/core-kunit: handle alloc failures on damon_test_merge_two()

[PATCH 5.15.y] mm/damon/tests/core-kunit: handle alloc failures on damon_test_merge_two()

[SeongJae Park]

damon_test_merge_two() 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/20251101182021.74868-7-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 3d443dd29a1db7efa587a4bb0c06a497e13ca9e4)
Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/core-test.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h
index 7008c3735e99..d22c86d5148b 100644
--- a/mm/damon/core-test.h
+++ b/mm/damon/core-test.h
@@ -144,10 +144,20 @@ static void damon_test_merge_two(struct kunit *test)
 	int i;
 
 	t = damon_new_target(42);
+	if (!t)
+		kunit_skip(test, "target alloc fail");
 	r = damon_new_region(0, 100);
+	if (!r) {
+		damon_free_target(t);
+		kunit_skip(test, "region alloc fail");
+	}
 	r->nr_accesses = 10;
 	damon_add_region(r, t);
 	r2 = damon_new_region(100, 300);
+	if (!r2) {
+		damon_free_target(t);
+		kunit_skip(test, "second region alloc fail");
+	}
 	r2->nr_accesses = 20;
 	damon_add_region(r2, t);
 
-- 
2.47.3