mm/damon/tests/core-kunit: handle allocation failures in damon_test_regions()

commit e16fdd4f754048d6e23c56bd8d920b71e41e3777 upstream.

damon_test_regions() 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/20251101182021.74868-3-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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h
index 7008c3735e99f1d486109aeb8d9b3ccfbf68b6fb..e5917267551dffa170fc98a9a46c8c583a864046 100644 (file)
--- a/mm/damon/core-test.h
+++ b/mm/damon/core-test.h
@@ -20,11 +20,17 @@ static void damon_test_regions(struct kunit *test)
        struct damon_target *t;
 
        r = damon_new_region(1, 2);
+       if (!r)
+               kunit_skip(test, "region alloc fail");
        KUNIT_EXPECT_EQ(test, 1ul, r->ar.start);
        KUNIT_EXPECT_EQ(test, 2ul, r->ar.end);
        KUNIT_EXPECT_EQ(test, 0u, r->nr_accesses);
 
        t = damon_new_target(42);
+       if (!t) {
+               damon_free_region(r);
+               kunit_skip(test, "target alloc fail");
+       }
        KUNIT_EXPECT_EQ(test, 0u, damon_nr_regions(t));
 
        damon_add_region(r, t);