---
id: CVE-2026-68164
title: 'mm/damon/core: disallow overlapping input ranges for damon_set_regions()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/damon/core: disallow overlapping input ranges for damon_set_regions()

  damon_set_regions() assumes the input ranges are sorted by the address and
  don't overlap each …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c <
    a5c453fffb6f2ce75fc10b5d8bc475f1758010bd
  - >-
    Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c <
    4b4a3e7ef7bb622237495db9ba4dfd7417d6530e
  - >-
    Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c <
    06a4beeeec8f03f0b3e9c78a98f1ae4f0f18cfbd
  - >-
    Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c <
    6ce0db97fb37ab8cf8596edca0e3de8618ab009a
  - >-
    Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c <
    e33adf96afb5883f84b0d98747976bde293e33cb
  - >-
    Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c <
    954157679ec34661c2e87e7eb796104a797c32db
  - Linux 5.19
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:43:18.408895Z'
published: '2026-08-10'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T16:44:59.784Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68164'
references:
  - url: 'https://git.kernel.org/stable/c/a5c453fffb6f2ce75fc10b5d8bc475f1758010bd'
  - url: 'https://git.kernel.org/stable/c/4b4a3e7ef7bb622237495db9ba4dfd7417d6530e'
  - url: 'https://git.kernel.org/stable/c/06a4beeeec8f03f0b3e9c78a98f1ae4f0f18cfbd'
  - url: 'https://git.kernel.org/stable/c/6ce0db97fb37ab8cf8596edca0e3de8618ab009a'
  - url: 'https://git.kernel.org/stable/c/e33adf96afb5883f84b0d98747976bde293e33cb'
  - url: 'https://git.kernel.org/stable/c/954157679ec34661c2e87e7eb796104a797c32db'
tags:
  - cve.org
epss: 0.00215
epssPercentile: 0.11958
ingestedAt: '2026-11-06T16:57:43.141Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

mm/damon/core: disallow overlapping input ranges for damon_set_regions()

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.

## Affected

- `Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c < a5c453fffb6f2ce75fc10b5d8bc475f1758010bd`
- `Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c < 4b4a3e7ef7bb622237495db9ba4dfd7417d6530e`
- `Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c < 06a4beeeec8f03f0b3e9c78a98f1ae4f0f18cfbd`
- `Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c < 6ce0db97fb37ab8cf8596edca0e3de8618ab009a`
- `Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c < e33adf96afb5883f84b0d98747976bde293e33cb`
- `Linux >= 97d482f4592fde2322c319f07bc54f3a0d37861c < 954157679ec34661c2e87e7eb796104a797c32db`
- `Linux 5.19`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.