CVE-2026-74643 (GCVE-0-2026-74643)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:32 – Updated: 2026-08-22 15:32
VLAI
Title
samples/damon/mtier: error out for zero quota goal target values
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 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.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: c5e67d40a10234541e220750297304df79aaedd0 , < e16b8d640ec99b28bc827560edcf9706e610c3aa (git)
Affected: c5e67d40a10234541e220750297304df79aaedd0 , < 684f271210becd7b8c4088f06c442499e48a43a0 (git)
Affected: c5e67d40a10234541e220750297304df79aaedd0 , < a16fd3ad9d89b05475864da97327870464611736 (git)
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Linux Linux Affected: 6.17
Unaffected: 0 , < 6.17 (semver)
Unaffected: 6.18.45 , ≤ 6.18.* (semver)
Unaffected: 7.1.9 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsamples/damon/mtier: error out for zero quota goal target values\n\nPatch series \"mm/damon: avoid division by zero from damos_quota_score()\".\n\nDAMON_SAMPLE_MTIER and DAMON_LRU_SORT allow the user to trigger division\nby zero in damos_quota_score().  Avoid it by adding parameters validation\nchecks.\n\n\nThis patch (of 2):\n\ndamos_quota_score() can trigger division by zero if the target_value is\nzero.  DAMON_SAMPLE_MTIER lets users set the target_value via\nnode0_mem_{used,free}_bp parameters.  It doesn\u0027t guard zero value case,\nthough.  As a result, users can trigger division by zero.  Fix the issue\nby returning an error when the user tries to start DAMON with zero\nnode0_mem_{used,free}_bp parameter values.\n\nDAMON_SAMPLE_MTIER is just a sample module, but the consequence is quite\nbad.  Also the zero node0_mem_free_bp parameter might look like a\nreasonable setup to some users.  Hence, the issue might really happen in\nthe real world.\n\nOne reliable way to reproduce the issue is like below:\n\n    # cd /sys/module/damon_sample_mtier/parameters\n    # echo 4096 \u003e node0_start_addr\n    # echo 8192 \u003e node0_end_addr\n    # echo 8192 \u003e node1_start_addr\n    # echo 81920 \u003e node1_end_addr\n    # echo 0 \u003e node0_mem_free_bp\n    # echo Y \u003e enabled\n    # dmesg -w\n    [...]\n    [18792.235916] Oops: divide error: 0000 [#1] SMP NOPTI\n    [...]\n    [18792.242787] RIP: 0010:damos_quota_score+0x6f/0x480\n    [...]\n\nThis issue was discovered [1] by Sashiko."
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      "title": "samples/damon/mtier: error out for zero quota goal target values",
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    "datePublished": "2026-08-22T15:32:21.140Z",
    "dateReserved": "2026-08-15T05:44:03.922Z",
    "dateUpdated": "2026-08-22T15:32:21.140Z",
    "state": "PUBLISHED"
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-24T11:10:46+00:00",
      "cve": "CVE-2026-74643",
      "id": "CVE-2026-74643",
      "initial_release_date": "2026-08-22T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: samples/damon/mtier: error out for zero quota goal target values",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74643.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.