+ mm-damon-sysfs-schemes-call-missing-mem_cgroup_iter_break.patch added to mm-hotfixes-unstable branch

+ mm-damon-sysfs-schemes-call-missing-mem_cgroup_iter_break.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/sysfs-schemes: call missing mem_cgroup_iter_break()
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-damon-sysfs-schemes-call-missing-mem_cgroup_iter_break.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-sysfs-schemes-call-missing-mem_cgroup_iter_break.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: SeongJae Park <sj@kernel.org>
Subject: mm/damon/sysfs-schemes: call missing mem_cgroup_iter_break()
Date: Sun, 26 Apr 2026 10:36:12 -0700

damon_sysfs_memcg_path_to_id() breaks mem_cgroup_iter() loop without
calling mem_cgroup_iter_break().  This leaks the cgroup reference.  Fix
the issue by calling mem_cgroup_iter_break() before the break.

The issue was discovered [1] by Sashiko.

Link: https://lore.kernel.org/20260426173625.86521-1-sj@kernel.org
Link: https://lore.kernel.org/20260423004148.74722-1-sj@kernel.org [1]
Fixes: 29cbb9a13f05 ("mm/damon/sysfs-schemes: implement scheme filters")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> # 6.3.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/sysfs-schemes.c |    1 +
 1 file changed, 1 insertion(+)

--- a/mm/damon/sysfs-schemes.c~mm-damon-sysfs-schemes-call-missing-mem_cgroup_iter_break
+++ a/mm/damon/sysfs-schemes.c
@@ -2594,6 +2594,7 @@ static int damon_sysfs_memcg_path_to_id(
 		if (damon_sysfs_memcg_path_eq(memcg, path, memcg_path)) {
 			*id = mem_cgroup_id(memcg);
 			found = true;
+			mem_cgroup_iter_break(NULL, memcg);
 			break;
 		}
 	}
_

Patches currently in -mm which might be from sj@kernel.org are

mm-damon-sysfs-schemes-protect-memcg_path-kfree-with-damon_sysfs_lock.patch
mm-damon-sysfs-schemes-protect-path-kfree-with-damon_sysfs_lock.patch
mm-damon-reclaim-detect-and-use-fresh-enabled-and-kdamond_pid-values.patch
mm-damon-lru_sort-detect-and-use-fresh-enabled-and-kdamond_pid-values.patch
mm-damon-stat-detect-and-use-fresh-enabled-value.patch
mm-damon-sysfs-schemes-call-missing-mem_cgroup_iter_break.patch
docs-mm-damon-maintainer-profile-add-ai-review-usage-guideline.patch