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

{
  "id": "cfaaff55ee48404214329e95a982e4bc8e7b93ae127fa7c35b4694b577a0bd7b",
  "url": "https://osv.dev/vulnerability/CVE-2026-74643",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "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.",
    "evidence": "osv:CVE-2026-74643",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.45",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.9",
            "evidence": "/affected/1/ranges"
          }
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        "affected_versions": []
      }
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    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-74643",
      "aliases": [
        "CVE-2026-74643"
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                  "fixed": "684f271210becd7b8c4088f06c442499e48a43a0"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74643.json"
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        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.17.0"
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                {
                  "fixed": "6.18.45"
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              ]
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            {
              "type": "ECOSYSTEM",
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                  "introduced": "6.19.0"
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                  "fixed": "7.1.9"
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            "name": "Kernel",
            "ecosystem": "Linux"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74643.json"
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      ],
      "modified": "2026-10-28T02:30:42.936644087Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/684f271210becd7b8c4088f06c442499e48a43a0",
        "https://git.kernel.org/stable/c/a16fd3ad9d89b05475864da97327870464611736",
        "https://git.kernel.org/stable/c/e16b8d640ec99b28bc827560edcf9706e610c3aa",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74643.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-74643",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74643.json"
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    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 510678,
  "published_at": "2026-08-22T15:32:21.14+00:00"
}