Re: [PATCH 6.6.y] mm/damon/core-kunit: handle region split failure in filter_out()

[sashiko-bot@kernel.org]

> damos_test_filter_out() test checks if damos_filter_match() of an address
> filter splits the region as expected under a given condition.  But, the
> test continued regardless of the split successes.  As a result, the later
> part of the test could dereference invalid pointers that returned from
> damon_next_region().  Further, it could corrupt memory from
> damon_destroy_region().
> 
> The consequent user impact (memory corruption) 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.
> 
> Link: https://lore.kernel.org/20260718001442.87129-5-sj@kernel.org
> Link: https://lore.kernel.org/20260714142352.100478-1-sj@kernel.org [1]
> Fixes: 26713c890875 ("mm/damon/core-test: add a unit test for __damos_filter_out()")
> Signed-off-by: SJ Park <sj@kernel.org>
> Cc: Brendan Higgins <brendan.higgins@linux.dev>
> Cc: <stable@vger.kernel.org> # 6.6.x
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> (cherry picked from commit 3423fe70395210e2f0cd795270292f6a27cd57b5)
> Signed-off-by: SJ Park <sj@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260909040751.175004-1-sj@kernel.org?part=1