Re: [PATCH] mm/damon/core: fix potential memory leak by cleaning ops_filter in damon_destroy_scheme

[SeongJae Park <sj@kernel.org>]

On Tue, 14 Oct 2025 16:42:25 +0800 Enze Li <lienze@kylinos.cn> wrote:

> Currently, damon_destroy_scheme() only cleans up the filter list but
> leaves ops_filter untouched, which could lead to memory leaks when
> a scheme is destroyed.
> 
> This patch ensures both filter and ops_filter are properly freed in
> damon_destroy_scheme(), preventing potential memory leaks.

Thank you for fixing this!

FYI the leak is not only potential but can easily be reproduced using the ops
damos filters.  For example, I was able to reproduce it using DAMON user-space
tool (damo), like below.

    $ sudo ./damo start
    $ sudo ./damo report access --snapshot_damos_filter allow anon

After the above steps I confirmed it leaks the memory using kmemleak.

> 
> Fixes: ab82e57981d0 ("mm/damon/core: introduce damos->ops_filters")
> Signed-off-by: Enze Li <lienze@kylinos.cn>

Reviewed-by: SeongJae Park <sj@kernel.org>


Thanks,
SJ

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