The patch titled Subject: mm/damon/sysfs-schemes: free old damon_sysfs_scheme_filter->memcg_path on write has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-sysfs-schemes-free-old-damon_sysfs_scheme_filter-memcg_path-on-write.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

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: free old damon_sysfs_scheme_filter->memcg_path on write Date: Thu, 19 Jun 2025 11:36:07 -0700

memcg_path_store() assigns a newly allocated memory buffer to filter->memcg_path, without deallocating the previously allocated and assigned memory buffer. As a result, users can leak kernel memory by continuously writing a data to memcg_path DAMOS sysfs file. Fix the leak by deallocating the previously set memory buffer.

Link: https://lkml.kernel.org/r/20250619183608.6647-2-sj@kernel.org Fixes: 7ee161f18b5d ("mm/damon/sysfs-schemes: implement filter directory") Signed-off-by: SeongJae Park sj@kernel.org Cc: Shuah Khan shuah@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-free-old-damon_sysfs_scheme_filter-memcg_path-on-write +++ a/mm/damon/sysfs-schemes.c @@ -472,6 +472,7 @@ static ssize_t memcg_path_store(struct k return -ENOMEM;

strscpy(path, buf, count + 1); + kfree(filter->memcg_path); filter->memcg_path = path; return count; } _

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

mm-damon-sysfs-schemes-free-old-damon_sysfs_scheme_filter-memcg_path-on-write.patch mm-damon-introduce-damon_stat-module.patch mm-damon-introduce-damon_stat-module-fix.patch mm-damon-stat-calculate-and-expose-estimated-memory-bandwidth.patch mm-damon-stat-calculate-and-expose-idle-time-percentiles.patch docs-admin-guide-mm-damon-add-damon_stat-usage-document.patch mm-damon-paddr-use-alloc_migartion_target-with-no-migration-fallback-nodemask.patch revert-mm-rename-alloc_demote_folio-to-alloc_migrate_folio.patch revert-mm-make-alloc_demote_folio-externally-invokable-for-migration.patch selftets-damon-add-a-test-for-memcg_path-leak.patch