GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-46020 (GCVE-0-2026-46020)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:56 – Updated: 2026-06-14 17:48
VLAI
Title
mm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp Patch series "mm/damon/core: validate damos_quota_goal->nid". node_mem[cg]_{used,free}_bp DAMOS quota goals receive the node id. The node id is used for si_meminfo_node() and NODE_DATA() without proper validation. As a result, privileged users can trigger an out of bounds memory access using DAMON_SYSFS. Fix the issues. The issue was originally reported [1] with a fix by another author. The original author announced [2] that they will stop working including the fix that was still in the review stage. Hence I'm restarting this. This patch (of 2): Users can set damos_quota_goal->nid with arbitrary value for node_mem_{used,free}_bp. But DAMON core is using those for si_meminfo_node() without the validation of the value. This can result in out of bounds memory access. The issue can actually triggered using DAMON user-space tool (damo), like below. $ sudo ./damo start --damos_action stat \ --damos_quota_goal node_mem_used_bp 50% -1 \ --damos_quota_interval 1s $ sudo dmesg [...] [ 65.565986] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098 Fix this issue by adding the validation of the given node. If an invalid node id is given, it returns 0% for used memory ratio, and 100% for free memory ratio.
Severity
7.1 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 0e1c773b501f33437d87b72c7d26080361e224b1 , < b09958e235f2b9cd3898b85a8529172afa80d212 (git)
Affected: 0e1c773b501f33437d87b72c7d26080361e224b1 , < bcad74078708f2330a45b55358ebc38f8f4b1127 (git)
Affected: 0e1c773b501f33437d87b72c7d26080361e224b1 , < 40250b2dded0604a112be605f3828700d80ad7c2 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.27 , ≤ 6.18.* (semver)
Unaffected: 7.0.4 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "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": "b09958e235f2b9cd3898b85a8529172afa80d212",
              "status": "affected",
              "version": "0e1c773b501f33437d87b72c7d26080361e224b1",
              "versionType": "git"
            },
            {
              "lessThan": "bcad74078708f2330a45b55358ebc38f8f4b1127",
              "status": "affected",
              "version": "0e1c773b501f33437d87b72c7d26080361e224b1",
              "versionType": "git"
            },
            {
              "lessThan": "40250b2dded0604a112be605f3828700d80ad7c2",
              "status": "affected",
              "version": "0e1c773b501f33437d87b72c7d26080361e224b1",
              "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": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.27",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.27",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.4",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: validate damos_quota_goal-\u003enid for node_mem_{used,free}_bp\n\nPatch series \"mm/damon/core: validate damos_quota_goal-\u003enid\".\n\nnode_mem[cg]_{used,free}_bp DAMOS quota goals receive the node id.  The\nnode id is used for si_meminfo_node() and NODE_DATA() without proper\nvalidation.  As a result, privileged users can trigger an out of bounds\nmemory access using DAMON_SYSFS.  Fix the issues.\n\nThe issue was originally reported [1] with a fix by another author.  The\noriginal author announced [2] that they will stop working including the\nfix that was still in the review stage.  Hence I\u0027m restarting this.\n\n\nThis patch (of 2):\n\nUsers can set damos_quota_goal-\u003enid with arbitrary value for\nnode_mem_{used,free}_bp.  But DAMON core is using those for\nsi_meminfo_node() without the validation of the value.  This can result in\nout of bounds memory access.  The issue can actually triggered using DAMON\nuser-space tool (damo), like below.\n\n    $ sudo ./damo start --damos_action stat \\\n    \t--damos_quota_goal node_mem_used_bp 50% -1 \\\n    \t--damos_quota_interval 1s\n    $ sudo dmesg\n    [...]\n    [   65.565986] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098\n\nFix this issue by adding the validation of the given node.  If an invalid\nnode id is given, it returns 0% for used memory ratio, and 100% for free\nmemory ratio."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-14T17:48:26.041Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b09958e235f2b9cd3898b85a8529172afa80d212"
        },
        {
          "url": "https://git.kernel.org/stable/c/bcad74078708f2330a45b55358ebc38f8f4b1127"
        },
        {
          "url": "https://git.kernel.org/stable/c/40250b2dded0604a112be605f3828700d80ad7c2"
        }
      ],
      "title": "mm/damon/core: validate damos_quota_goal-\u003enid for node_mem_{used,free}_bp",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-46020",
    "datePublished": "2026-05-27T12:56:21.920Z",
    "dateReserved": "2026-05-13T15:03:33.092Z",
    "dateUpdated": "2026-06-14T17:48:26.041Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-46020",
      "date": "2026-09-12",
      "epss": "0.00124",
      "percentile": "0.02421"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-46020\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-27T14:17:20.460\",\"lastModified\":\"2026-06-17T10:52:54.690\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nmm/damon/core: validate damos_quota_goal-\u003enid for node_mem_{used,free}_bp\\n\\nPatch series \\\"mm/damon/core: validate damos_quota_goal-\u003enid\\\".\\n\\nnode_mem[cg]_{used,free}_bp DAMOS quota goals receive the node id.  The\\nnode id is used for si_meminfo_node() and NODE_DATA() without proper\\nvalidation.  As a result, privileged users can trigger an out of bounds\\nmemory access using DAMON_SYSFS.  Fix the issues.\\n\\nThe issue was originally reported [1] with a fix by another author.  The\\noriginal author announced [2] that they will stop working including the\\nfix that was still in the review stage.  Hence I\u0027m restarting this.\\n\\n\\nThis patch (of 2):\\n\\nUsers can set damos_quota_goal-\u003enid with arbitrary value for\\nnode_mem_{used,free}_bp.  But DAMON core is using those for\\nsi_meminfo_node() without the validation of the value.  This can result in\\nout of bounds memory access.  The issue can actually triggered using DAMON\\nuser-space tool (damo), like below.\\n\\n    $ sudo ./damo start --damos_action stat \\\\\\n    \\t--damos_quota_goal node_mem_used_bp 50% -1 \\\\\\n    \\t--damos_quota_interval 1s\\n    $ sudo dmesg\\n    [...]\\n    [   65.565986] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098\\n\\nFix this issue by adding the validation of the given node.  If an invalid\\nnode id is given, it returns 0% for used memory ratio, and 100% for free\\nmemory ratio.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"mm/damon/core.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"0e1c773b501f33437d87b72c7d26080361e224b1\",\"lessThan\":\"b09958e235f2b9cd3898b85a8529172afa80d212\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0e1c773b501f33437d87b72c7d26080361e224b1\",\"lessThan\":\"bcad74078708f2330a45b55358ebc38f8f4b1127\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0e1c773b501f33437d87b72c7d26080361e224b1\",\"lessThan\":\"40250b2dded0604a112be605f3828700d80ad7c2\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"mm/damon/core.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.16\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.16\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.27\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.4\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.2}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-125\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.16\",\"versionEndExcluding\":\"6.18.27\",\"matchCriteriaId\":\"24BD5AA7-843C-41A3-8471-F53AD6DB7C6B\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.19\",\"versionEndExcluding\":\"7.0.4\",\"matchCriteriaId\":\"CDB78D6D-22C3-4154-B0D0-94AF1CE5C2E3\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/40250b2dded0604a112be605f3828700d80ad7c2\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/b09958e235f2b9cd3898b85a8529172afa80d212\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/bcad74078708f2330a45b55358ebc38f8f4b1127\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-28T06:45:53+00:00",
      "cve": "CVE-2026-46020",
      "id": "CVE-2026-46020",
      "initial_release_date": "2026-05-27T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: mm/damon/core: validate damos_quota_goal-\u003enid for node_mem_{used,free}_bp",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46020.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-27T16:57:16Z",
      "cve": "CVE-2026-46020",
      "id": "CVE-2026-46020",
      "initial_release_date": "2026-05-28T03:54:16Z",
      "product_status:known_not_affected": "299",
      "product_status:recommended": "4",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-46020",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-46020.json",
      "version": "5"
    }
  }
}