FKIE_CVE-2026-99240

Vulnerability from fkie_nvd - Published: 2026-11-02 16:17 - Updated: 2026-11-03 20:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: error damos_commit_quota_goal() for zero target_value Patch series "mm/damon: move zero damos quota target_value handling to the core layer". Having zero DAMOS quota target value can cause division by zero. DAMON API callers are checking the target value parameters to avoid that. It is easy to make mistakes in some of the multiple API callers. Move that to the core layer. Patch 1 adds the corner case handling into the core layer DAMON parameters validation logic. Patches 2 and 3 remove no more needed DAMON API callers side handling of the corner case in DAMON_LRU_SORT and DMON_SAMPLIE_MTIER, respectively. This patch (of 3): If a DAMOS scheme has a damos_quota_goal of zero target_value, damos_quota_goal() could trigger division-by-zero error. Hence each DAMON API callers should do the zero target_value validation. It is easy to make mistakes. Actually such bugs in DAMON_LRU_SORT and DAMON_SAMPLE_MTIER were found and fixed [1]. It is better to handle the corner case only once in the core layer, instead of multiple places in all DAMON API callers. One straightforward option is using an alternative denominator for the corner case in the damos_quota_goal(). However, the zero target_value is meaningless. In this case, the quota goal is always evaluated as achieved or over-achieved. The quota will only keep being reduced. Simply avoid using zero target_value by adding a check in the core layer DAMOS quota goal parameters validation/commit path, damos_commit_quota_goal(). Update it to return an error in the case. Also update its caller to propagate the error.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/156aeda4d74e9007b56492ed1f3b5838822632be
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/610c4438fb66e06d9e693c0ad3b2c1be54c0d61f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cc190c4073f570fd78a9d00dd3d13a71eced5403
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d5482be6243b816730689099c017109eb8730dd5
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "mm/damon/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d5482be6243b816730689099c017109eb8730dd5",
              "status": "affected",
              "version": "c5e67d40a10234541e220750297304df79aaedd0",
              "versionType": "git"
            },
            {
              "lessThan": "cc190c4073f570fd78a9d00dd3d13a71eced5403",
              "status": "affected",
              "version": "c5e67d40a10234541e220750297304df79aaedd0",
              "versionType": "git"
            },
            {
              "lessThan": "156aeda4d74e9007b56492ed1f3b5838822632be",
              "status": "affected",
              "version": "c5e67d40a10234541e220750297304df79aaedd0",
              "versionType": "git"
            },
            {
              "lessThan": "610c4438fb66e06d9e693c0ad3b2c1be54c0d61f",
              "status": "affected",
              "version": "c5e67d40a10234541e220750297304df79aaedd0",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "mm/damon/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.60",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.3.*",
              "status": "unaffected",
              "version": "7.3.1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.4-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: error damos_commit_quota_goal() for zero target_value\n\nPatch series \"mm/damon: move zero damos quota target_value handling to the\ncore layer\".\n\nHaving zero DAMOS quota target value can cause division by zero.  DAMON\nAPI callers are checking the target value parameters to avoid that.  It is\neasy to make mistakes in some of the multiple API callers.  Move that to\nthe core layer.\n\nPatch 1 adds the corner case handling into the core layer DAMON parameters\nvalidation logic.  Patches 2 and 3 remove no more needed DAMON API callers\nside handling of the corner case in DAMON_LRU_SORT and DMON_SAMPLIE_MTIER,\nrespectively.\n\n\nThis patch (of 3):\n\nIf a DAMOS scheme has a damos_quota_goal of zero target_value,\ndamos_quota_goal() could trigger division-by-zero error.  Hence each DAMON\nAPI callers should do the zero target_value validation.  It is easy to\nmake mistakes.  Actually such bugs in DAMON_LRU_SORT and\nDAMON_SAMPLE_MTIER were found and fixed [1].\n\nIt is better to handle the corner case only once in the core layer,\ninstead of multiple places in all DAMON API callers.  One straightforward\noption is using an alternative denominator for the corner case in the\ndamos_quota_goal().  However, the zero target_value is meaningless.  In\nthis case, the quota goal is always evaluated as achieved or\nover-achieved.  The quota will only keep being reduced.\n\nSimply avoid using zero target_value by adding a check in the core layer\nDAMOS quota goal parameters validation/commit path,\ndamos_commit_quota_goal().  Update it to return an error in the case. \nAlso update its caller to propagate the error."
    }
  ],
  "id": "CVE-2026-99240",
  "lastModified": "2026-11-03T20:18:30.493",
  "metrics": {},
  "published": "2026-11-02T16:17:49.773",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/156aeda4d74e9007b56492ed1f3b5838822632be"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/610c4438fb66e06d9e693c0ad3b2c1be54c0d61f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cc190c4073f570fd78a9d00dd3d13a71eced5403"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d5482be6243b816730689099c017109eb8730dd5"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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