6.18-stable review patch. If anyone has any objections, please let me know.
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From: SeongJae Park sj@kernel.org
commit b5ab490d85b772bc99d2648182a282f39f08feb6 upstream.
Patch series "mm/damon/tests: fix memory bugs in kunit tests".
DAMON kunit tests were initially written assuming those will be run on environments that are well controlled and therefore tolerant to transient test failures and bugs in the test code itself. The user-mode linux based manual run of the tests is one example of such an environment. And the test code was written for adding more test coverage as fast as possible, over making those safe and reliable.
As a result, the tests resulted in having a number of bugs including real memory leaks, theoretical unhandled memory allocation failures, and unused memory allocations. The allocation failures that are not handled well are unlikely in the real world, since those allocations are too small to fail. But in theory, it can happen and cause inappropriate memory access.
It is arguable if bugs in test code can really harm users. But, anyway bugs are bugs that need to be fixed. Fix the bugs one by one. Also Cc stable@ for the fixes of memory leak and unhandled memory allocation failures. The unused memory allocations are only a matter of memory efficiency, so not Cc-ing stable@.
The first patch fixes memory leaks in the test code for the DAMON core layer.
Following fifteen, three, and one patches respectively fix unhandled memory allocation failures in the test code for DAMON core layer, virtual address space DAMON operation set, and DAMON sysfs interface, one by one per test function.
Final two patches remove memory allocations that are correctly deallocated at the end, but not really being used by any code.
This patch (of 22):
Kunit test function for damos_set_filters_default_reject() allocates two 'struct damos_filter' objects and not deallocates those, so that the memory for the two objects are leaked for every time the test runs. Fix this by deallocating those objects at the end of the test code.
Link: https://lkml.kernel.org/r/20251101182021.74868-1-sj@kernel.org Link: https://lkml.kernel.org/r/20251101182021.74868-2-sj@kernel.org Fixes: 094fb14913c7 ("mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()") 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 [6.16+] Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/damon/tests/core-kunit.h | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index 51369e35298b..69ca44f9270b 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -598,6 +598,9 @@ static void damon_test_set_filters_default_reject(struct kunit *test) */ KUNIT_EXPECT_EQ(test, scheme.core_filters_default_reject, false); KUNIT_EXPECT_EQ(test, scheme.ops_filters_default_reject, true); + + damos_free_filter(anon_filter); + damos_free_filter(target_filter); }
static struct kunit_case damon_test_cases[] = {