mm/damon/tests/vaddr-kunit: handle alloc failures in damon_test_split_evenly_fail()

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>

diff --git a/mm/damon/tests/vaddr-kunit.h b/mm/damon/tests/vaddr-kunit.h
index 484223f195459d25097f0853245bcf211d4c469c..1b0f21c2e37630801f6d1bd712538e5b60870cd7 100644 (file)
--- a/mm/damon/tests/vaddr-kunit.h
+++ b/mm/damon/tests/vaddr-kunit.h
@@ -256,7 +256,16 @@ 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,