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

commit 7890e5b5bb6e386155c6e755fe70e0cdcc77f18e upstream.

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>
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
index 5531766ff09fa9c3ac2c34ae4362f24e9f4e0244..eaf579a054b4bd93046b190a8cd2b7b018b6819b 100644 (file)
--- a/mm/damon/vaddr-test.h
+++ b/mm/damon/vaddr-test.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(42);
-       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,