damos_test_commit_dests_for() traverse damos action destinations after damos_commit_dests(). It assumes damos_commit_dests() made expected numbers of destinations for source and destination structures. It might not. Because the traversal is made based on destination struct length, it could do out of bounds access for source value expectation.
The consequent user impact (out-of-bound access ) is quite bad. The realistic user impact would be limited, though. It would affect only test run setups. Fix it by exiting early for the number of regions test failure. The issue was discovered [1] by Sashiko. [1] https://lore.kernel.org/[email protected] Fixes: eec573b8dd65 ("mm/damon/tests/core-kunit: add damos_commit_dests() test") Cc: <[email protected]> # 6.19.x Signed-off-by: SJ Park <[email protected]> --- mm/damon/tests/core-kunit.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index eddf3a0484583..9b8c20a50ad53 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -1008,6 +1008,8 @@ static void damos_test_commit_dests_for(struct kunit *test, skip = false; KUNIT_EXPECT_EQ(test, dst.nr_dests, src_nr_dests); + if (dst.nr_dests != src_nr_dests) + goto out; for (i = 0; i < dst.nr_dests; i++) { KUNIT_EXPECT_EQ(test, dst.node_id_arr[i], src_node_id_arr[i]); KUNIT_EXPECT_EQ(test, dst.weight_arr[i], src_weight_arr[i]); -- 2.47.3
