---
id: CVE-2026-74643
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  samples/damon/mtier: error out for zero quota goal target values

  Patch series "mm/damon: avoid division by zero from damos_quota_score()".

  DAMON_SAMPLE_MTIER and DAMO…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  samples/damon/mtier: error out for zero quota goal target values

  Patch series "mm/damon: avoid division by zero from damos_quota_score()".

  DAMON_SAMPLE_MTIER and DAMO…
severity: none
published: '2026-08-22'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74643'
references:
  - url: 'https://git.kernel.org/stable/c/684f271210becd7b8c4088f06c442499e48a43a0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a16fd3ad9d89b05475864da97327870464611736'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e16b8d640ec99b28bc827560edcf9706e610c3aa'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00206
epssPercentile: 0.09945
ingestedAt: '2026-10-14T13:30:58.524Z'
---

## Overview

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

samples/damon/mtier: error out for zero quota goal target values

Patch series "mm/damon: avoid division by zero from damos_quota_score()".

DAMON_SAMPLE_MTIER and DAMON_LRU_SORT allow the user to trigger division
by zero in damos_quota_score().  Avoid it by adding parameters validation
checks.


This patch (of 2):

damos_quota_score() can trigger division by zero if the target_value is
zero.  DAMON_SAMPLE_MTIER lets users set the target_value via
node0_mem_{used,free}_bp parameters.  It doesn't guard zero value case,
though.  As a result, users can trigger division by zero.  Fix the issue
by returning an error when the user tries to start DAMON with zero
node0_mem_{used,free}_bp parameter values.

DAMON_SAMPLE_MTIER is just a sample module, but the consequence is quite
bad.  Also the zero node0_mem_free_bp parameter might look like a
reasonable setup to some users.  Hence, the issue might really happen in
the real world.

One reliable way to reproduce the issue is like below:

    # cd /sys/module/damon_sample_mtier/parameters
    # echo 4096 > node0_start_addr
    # echo 8192 > node0_end_addr
    # echo 8192 > node1_start_addr
    # echo 81920 > node1_end_addr
    # echo 0 > node0_mem_free_bp
    # echo Y > enabled
    # dmesg -w
    [...]
    [18792.235916] Oops: divide error: 0000 [#1] SMP NOPTI
    [...]
    [18792.242787] RIP: 0010:damos_quota_score+0x6f/0x480
    [...]

This issue was discovered [1] by Sashiko.

## Remediation

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