[PATCH 6.1.y] mm/damon/tests/core-kunit: handle alloc failures on damon_test_split_at()

[SeongJae Park <sj@kernel.org>]

damon_test_split_at() 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/20251101182021.74868-6-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 5e80d73f22043c59c8ad36452a3253937ed77955)
Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/core-test.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h
index 3db9b7368756..4846d645d278 100644
--- a/mm/damon/core-test.h
+++ b/mm/damon/core-test.h
@@ -123,8 +123,19 @@ static void damon_test_split_at(struct kunit *test)
 	struct damon_target *t;
 	struct damon_region *r;
 
+	if (!c)
+		kunit_skip(test, "ctx alloc fail");
 	t = damon_new_target();
+	if (!t) {
+		damon_destroy_ctx(c);
+		kunit_skip(test, "target alloc fail");
+	}
 	r = damon_new_region(0, 100);
+	if (!r) {
+		damon_destroy_ctx(c);
+		damon_free_target(t);
+		kunit_skip(test, "region alloc fail");
+	}
 	damon_add_region(r, t);
 	damon_split_region_at(t, r, 25);
 	KUNIT_EXPECT_EQ(test, r->ar.start, 0ul);
-- 
2.47.3