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 B9D1838758E; Thu, 9 Jul 2026 22:50:00 +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=1783637402; cv=none; b=BlIhqGm9QDbBn4cchx+Fn6WHvnoumQ41xEBOcIqmwJFCVto6rpvGclYN6AuQhQslK9EYhbVeZJ4Okl35vndN9+Y5iQM/MCCkH4L+uqIq6ns8MXuhjOYP5CvuqfTwNfdS19vRITaZbBeXrmXXJqB65BO03+KXAvg+m1Mq9lFzXVY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783637402; c=relaxed/simple; bh=q4zHfxqdYz8nMmjhWgvEjUVPdnhDAsf/E0pzf+hIAnE=; h=Date:To:From:Subject:Message-Id; b=RBLJKBM/m+I4pj7cPf+WE26N6JfF1JRqO9f6w34AwZ/PzLVMDig5f0biJqL9eyE7Tzngf6MtUo82/wHHDtuAL2pOMwuiIbZfvNFZQCN8BXs3oSHGmoFMO61EcR+xeWJRunE2eOiegmT7DtSba7YCHomQu5iMtzWSxMk7TXrdtiM= 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=I7tapnvU; 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="I7tapnvU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 909C91F00A3A; Thu, 9 Jul 2026 22:50:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1783637400; bh=f+t9BrulyRDCMgaJKURkjKAo6aWIB8yIrpVj3h/DrOQ=; h=Date:To:From:Subject; b=I7tapnvU/G1i0g3WdhpQQucQWsJsQVgMdBIiRG2Xwd/niy8WzmbhoZPTa0KPpxbxl ZPQ7yf4ULneYcHDXBDkEYUczPAzTEeRU4ZhfEPzAv+pGXWuDruntCiH2zBY2geucPj /CnOs3OMvocIYiEr+lvO9KAzA/+K9bnBGbiFhrOY= Date: Thu, 09 Jul 2026 15:50:00 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-damon-core-disallow-overlapping-input-ranges-for-damon_set_regions.patch removed from -mm tree Message-Id: <20260709225000.909C91F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/damon/core: disallow overlapping input ranges for damon_set_regions() has been removed from the -mm tree. Its filename was mm-damon-core-disallow-overlapping-input-ranges-for-damon_set_regions.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: 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 @@ -354,12 +354,19 @@ 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 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-safely-validate-src-on-damon_commit_ctx.patch mm-damon-core-do-parameter-testing-commit-on-damon_start.patch mm-damon-sysfs-remove-duplicated-commit-input-validity-check.patch mm-damon-reclaim-remove-duplicated-min_region_sz-power-of-2-check.patch mm-damon-lru_sort-remove-duplicated-min_region_sz-power_of_2-check.patch mm-damon-document-region-size-validation-in-damon_set_regions.patch mm-damon-core-remove-start-end-check-in-damon_set_region_system_rams.patch mm-damon-sysfs-remove-region-size-validation.patch mm-damon-core-stop-ctxs-in-damon_start-before-returning-an-error.patch samples-damon-mtier-do-not-stop-first-context-for-damon_start-failure.patch mm-damon-core-make-damon_stop-never-fails.patch mm-damon-sysfs-ignore-damon_stop-return-value.patch mm-damon-reclaaim-ignore-damon_stop-return-value.patch mm-damon-lru_sort-ignore-damon_stop-return-value.patch mm-damon-core-change-damon_stop-return-type-to-void.patch samples-damon-mtier-stop-all-contexts-with-single-damon_stop-call.patch mm-damon-core-wait-ctx-stop-in-damon_call-before-reruning-an-error.patch samples-damon-wsse-do-not-stop-ctx-for-damon_call-failure.patch samples-damon-prcl-do-not-stop-damon-for-damon_call-failure.patch mm-damon-core-remove-comment-and-test-for-nr_to_bp-divide-by-zero.patch mm-damon-core-s-damon_max_nr_accesses-damon_nr_samples_per_aggr.patch mm-damon-core-s-accesses_bp_to_nr_accesses-sample_bp_to_count.patch mm-damon-core-s-nr_accesses_to_accesses_bp-sample_count_to_bp.patch mm-damon-core-s-nr_accesses_for_new_attrs-nr_samples_for_new_attrs.patch mm-damon-core-update-probe-hits-for-new-parameter-commit.patch mm-damon-core-handle-unreset-probe_hits-in-probe_hits_mvsum.patch