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mm-damon-sysfs-schemes-skip-stats-update-if-the-scheme-directory-is-removed.patch removed from -mm tree

merged mm-hotfixes-stable Andrew Morton 1 participant 1 message Nov 23, 2022 Stable branch

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The quilt patch titled
Subject: mm/damon/sysfs-schemes: skip stats update if the scheme directory is removed
has been removed from the -mm tree. Its filename was
mm-damon-sysfs-schemes-skip-stats-update-if-the-scheme-directory-is-removed.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: SeongJae Park <[email protected]>
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.

Fixes 0ac32b8affb5 ("mm/damon/sysfs: support DAMOS stats")
Cc <[email protected]> [v5.18]

---

 mm/damon/sysfs.c |    4 ++++
 1 file changed, 4 insertions(+)
mm/damon/sysfs.c renamed from mm/damon/sysfs.c~mm-damon-sysfs-schemes-skip-stats-update-if-the-scheme-directory-is-removed +4 -0
@@ -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 have 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 [email protected] are

mm-damon-sysfs-fix-wrong-empty-schemes-assumption-under-online-tuning-in-damon_sysfs_set_schemes.patch mm-damon-core-split-out-damos-charged-region-skip-logic-into-a-new-function.patch mm-damon-core-split-damos-application-logic-into-a-new-function.patch mm-damon-core-split-out-scheme-stat-update-logic-into-a-new-function.patch mm-damon-core-split-out-scheme-quota-adjustment-logic-into-a-new-function.patch mm-damon-sysfs-use-damon_addr_range-for-regions-start-and-end-values.patch mm-damon-sysfs-remove-parameters-of-damon_sysfs_region_alloc.patch mm-damon-sysfs-move-sysfs_lock-to-common-module.patch mm-damon-sysfs-move-unsigned-long-range-directory-to-common-module.patch mm-damon-sysfs-split-out-kdamond-independent-schemes-stats-update-logic-into-a-new-function.patch mm-damon-sysfs-split-out-schemes-directory-implementation-to-separate-file.patch mm-damon-modules-deduplicate-init-steps-for-damon-context-setup.patch mm-damon-reclaimlru_sort-remove-unnecessarily-included-headers.patch mm-damon-reclaim-enable-and-disable-synchronously.patch selftests-damon-add-tests-for-damon_reclaims-enabled-parameter.patch mm-damon-lru_sort-enable-and-disable-synchronously.patch selftests-damon-add-tests-for-damon_lru_sorts-enabled-parameter.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