The patch titled Subject: mm/damon/sysfs-schemes: skip stats update if the scheme directory is removed has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-sysfs-schemes-skip-stats-update-if-the-scheme-directory-is-removed.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: skip stats update if the scheme directory is removed Date: Mon, 14 Nov 2022 17:55:52 +0000

A DAMON sysfs interface user can start DAMON with a scheme, remove the sysfs directory for the scheme, and then ask update of the scheme's stats. Because the schemes stats update logic isn't aware of the situation, it results in an invalid memory access. Fix the bug by checking if the scheme sysfs directory exists.

Link: https://lkml.kernel.org/r/20221114175552.1951-1-sj@kernel.org Fixes: 0ac32b8affb5 ("mm/damon/sysfs: support DAMOS stats") Signed-off-by: SeongJae Park sj@kernel.org Cc: stable@vger.kernel.org [v5.18] Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/damon/sysfs.c | 4 ++++ 1 file changed, 4 insertions(+)

--- a/mm/damon/sysfs.c~mm-damon-sysfs-schemes-skip-stats-update-if-the-scheme-directory-is-removed +++ a/mm/damon/sysfs.c @@ -2339,6 +2339,10 @@ static int damon_sysfs_upd_schemes_stats damon_for_each_scheme(scheme, ctx) { struct damon_sysfs_stats *sysfs_stats;

+ /* user could removed the scheme sysfs dir */ + if (schemes_idx >= sysfs_schemes->nr) + break; + sysfs_stats = sysfs_schemes->schemes_arr[schemes_idx++]->stats; sysfs_stats->nr_tried = scheme->stat.nr_tried; sysfs_stats->sz_tried = scheme->stat.sz_tried; _

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

mm-damon-sysfs-schemes-skip-stats-update-if-the-scheme-directory-is-removed.patch docs-admin-guide-mm-damon-usage-describe-the-rules-of-sysfs-region-directories.patch docs-admin-guide-mm-damon-usage-fix-wrong-usage-example-of-init_regions-file.patch mm-damon-core-add-a-callback-for-scheme-target-regions-check.patch mm-damon-sysfs-schemes-implement-schemes-tried_regions-directory.patch mm-damon-sysfs-schemes-implement-scheme-region-directory.patch mm-damon-sysfs-implement-damos-tried-regions-update-command.patch mm-damon-sysfs-implement-damos-tried-regions-update-command-fix.patch mm-damon-sysfs-schemes-implement-damos-tried-regions-clear-command.patch mm-damon-sysfs-schemes-implement-damos-tried-regions-clear-command-fix.patch tools-selftets-damon-sysfs-test-tried_regions-directory-existence.patch docs-admin-guide-mm-damon-usage-document-schemes-s-tried_regions-sysfs-directory.patch docs-abi-damon-document-schemes-s-tried_regions-sysfs-directory.patch selftests-damon-test-non-context-inputs-to-rm_contexts-file.patch