From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8EC1086341; Sun, 5 Jul 2026 02:06:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783217177; cv=none; b=nqMlitisVD/TSREE4PqFbc75JWaKTDO0aYvu5hSTk6NYSx4rppKFkHe930p5N0mqyVZTwzCAnFCEhGNLgpOqZbofz7PEHq+wTkftOpklU5JQh/fcGl56o2W/1R5II0lfZzjw8FYAQe2uowO7RpWD8M+GOBqv0bUW9pdLgYxuarE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783217177; c=relaxed/simple; bh=ZwbOnAnjl0Ux9l88oFp/f/kWnagXTnj0BDx2zFBiawg=; h=Date:To:From:Subject:Message-Id; b=V9spc7+uQ7aY2QQYQdwboN9llWXbVQdc+9jOKy9vpZtwmMm7rACpdSTIQdAB2w8VjSollDN92Q3jhMDA3AF6c6zOgucPzEH7Jb/wtl/xf/2ijrVV0ODEMDA7M1r415CkQ0d1MzY1DfVcFB4zsGUaEoQYe+Cy8/fKsDym2t4czaY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=Ppyya3ku; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Ppyya3ku" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B4AD1F000E9; Sun, 5 Jul 2026 02:06:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1783217176; bh=lDICBNgjO9IwRBfk4RidNPaEOeUf1F72JLRZ4tA0kiM=; h=Date:To:From:Subject; b=Ppyya3kuRoqFKm6E1KWw1a/Fzec8qIzOyG3XNDNNHPvOeyJaheFn4pU8EQB3XaSGs 38ujhKJJGAS/pFnwtJiCwbEb9AVq2lPMJumiC2An9LhHYSIECYcEPnVxgsWxIoZg8x sYVkdxk4jot2M8NPtNKnmKpXUSUL5FW4Sh6MlLQk= Date: Sat, 04 Jul 2026 19:06:15 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-damon-core-disallow-overlapping-input-ranges-for-damon_set_regions.patch added to mm-nonmm-unstable branch Message-Id: <20260705020616.1B4AD1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/damon/core: disallow overlapping input ranges for damon_set_regions() has been added to the -mm mm-nonmm-unstable branch. Its filename is mm-damon-core-disallow-overlapping-input-ranges-for-damon_set_regions.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-core-disallow-overlapping-input-ranges-for-damon_set_regions.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: SJ Park Subject: mm/damon/core: disallow overlapping input ranges for damon_set_regions() Date: Fri, 3 Jul 2026 09:56:08 -0700 damon_set_regions() assumes the input ranges are sorted by the address and don't overlap each other. Hence the assumption was initially to be explicitly validated. But commit 97d482f4592f ("mm/damon/sysfs: reuse damon_set_regions() for regions setting") has mistakenly removed the validation. This can make DAMON behave in unexpected ways. At the best, the monitoring results snapshot will just look weird since there will be overlapping regions. DAMOS will also work weirdly, applying the same action multiple times for overlapping regions, and make DAMOS quota weird. More seriously, depending on the setup and regions updates sequence, negative size regions can be made. It will trigger WARN_ONCE() if the kernel is built with CONFIG_DAMON_DEBUG_SANITY=y. Depending on the monitoring results, the negative size region can further trigger division by zero in damon_merge_two_regions(). Note that some of the consequences including the WARN_ONCE() and the divide by zero depend on commits that were introduced after the root cause commit 97d482f4592f ("mm/damon/sysfs: reuse damon_set_regions() for regions setting"). Fix the problems by checking the assumption and returning an error if the input ranges don't meet the assumption. The issue was discovered [1] by Sashiko. Link: https://lore.kernel.org/20260703165610.92894-1-sj@kernel.org Link: https://lore.kernel.org/20260630041806.151124-1-sj@kernel.org [1] Fixes: 97d482f4592f ("mm/damon/sysfs: reuse damon_set_regions() for regions setting") Signed-off-by: SJ Park Cc: # 5.19.x Signed-off-by: Andrew Morton --- mm/damon/core.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/mm/damon/core.c~mm-damon-core-disallow-overlapping-input-ranges-for-damon_set_regions +++ a/mm/damon/core.c @@ -441,12 +441,19 @@ int damon_set_regions(struct damon_targe { struct damon_region *r, *next; unsigned int i; + unsigned long last_end; int err; for (i = 0; i < nr_ranges; i++) { - if (ALIGN_DOWN(ranges[i].start, min_region_sz) >= - ALIGN(ranges[i].end, min_region_sz)) + unsigned long start, end; + + start = ALIGN_DOWN(ranges[i].start, min_region_sz); + end = ALIGN(ranges[i].end, min_region_sz); + if (start >= end) + return -EINVAL; + if (i > 0 && last_end > start) return -EINVAL; + last_end = end; } /* Remove regions which are not in the new ranges */ _ Patches currently in -mm which might be from sj@kernel.org are maintainers-s-seongjae-sj.patch mm-damon-core-validate-ranges-in-damon_set_regions.patch samples-damon-wsse-handle-damon_start-failure.patch samples-damon-prcl-handle-damon_start-failure.patch samples-damon-mtier-handle-damon_start-failure.patch samples-damon-mtier-handle-damon_stop-failure.patch samples-damon-wsse-stop-and-free-damon-ctx-when-damon_call-fails.patch samples-damon-prcl-stop-and-free-damon-ctx-when-damon_call-fails.patch mm-damon-sysfs-kobject_del-target-normal-context-and-kdamond-dirs.patch mm-damon-sysfs-kobject_del-region-and-target-error-dirs.patch mm-damon-sysfs-schemes-kobject_del-scheme-dirs.patch mm-damon-sysfs-schemes-kobject_del-scheme-region-dirs.patch mm-damon-sysfs-schemes-kobject_del-scheme-filter-dirs.patch mm-damon-sysfs-schemes-kobject_del-scheme-quota-goal-dirs.patch mm-damon-sysfs-schemes-kobject_del-scheme-action-destination-dirs.patch mm-damon-sysfs-kobject_del-probe-dirs.patch mm-damon-sysfs-kobject_del-probe-filter-dirs.patch mm-damon-sysfs-kobject_del-probe-dirs-in-probes_addd_dir-error-path.patch mm-damon-sysfs-schemes-kobject_del-region-for-populate_region-error.patch docs-mm-damon-design-update-for-damos_quota_node_eligible_mem_bp.patch docs-abi-damon-document-probe-files.patch mm-damon-tests-core-kunit-test-damon_rand.patch selftests-damon-sysfssh-test-multiple-probe-dirs-creation.patch selftests-damon-sysfssh-test-coreops_filters-directories.patch selftests-damon-sysfssh-test-dests-dir.patch selftests-damon-sysfssh-test-all-files-in-quota-goal-dir.patch mm-damon-core-reduce-range-setup-in-damon_commit_target_regions.patch mm-damon-sysfs-split-probe-setup-function-out.patch mm-damon-sysfs-split-out-filters-setup-function.patch mm-damon-sysfs-fix-typos-in-probe_addrm_dirs-s-attr-probe.patch mm-damon-core-introduce-damon_nr_accesses_mvsum.patch mm-damon-tests-core-kunit-test-damon_mvsum.patch mm-damon-core-always-update-last_nr_accesses-for-intervals-change.patch mm-damon-core-handle-unreset-nr_accesses-in-damon_nr_accesses_mvsum.patch mm-damon-core-use-damon_nr_accesses_mvsum-in-__damos_valid_target.patch mm-damon-core-use-damon_nr_accesses_mvsum-for-damos-region-tracing.patch mm-damon-sysfs-schemes-use-damon_nr_accesses_mvsum-for-damo-regions.patch mm-damon-core-remove-damon_warn_fix_nr_accesses_corruption.patch mm-damon-core-remove-damon_verify_reset_aggregated.patch mm-damon-core-remove-damon_verify_merge_regions_of.patch mm-damon-tests-core-kunit-remove-nr_accesses_bp-setup-and-tests.patch selftests-damon-drgn_dump_damon_status-do-not-dump-nr_accesses_bp.patch mm-damon-core-remove-nr_accesses_bp-setups-and-updates.patch mm-damon-core-remove-attrs-param-from-damon_update_region_access_rate.patch mm-damon-paddr-remove-attrs-param-from-__damon_pa_check_access.patch mm-damon-vaddr-remove-attrs-param-from-__damon_va_check_access.patch mm-damon-core-remove-damon_moving_sum-and-its-unit-test.patch mm-damon-core-remove-damon_region-nr_accesses_bp.patch mm-damon-add-damon_region-last_probe_hits.patch mm-damon-core-introduce-damon_probe_hits_mvsum.patch mm-damon-sysfs-schemes-set-probe-hits-as-pseudo-moving-sums.patch mm-damon-core-disallow-overlapping-input-ranges-for-damon_set_regions.patch