mm/damon/core: avoid use of half-online-committed context

{
  "id": "b14c04a23809b436a20328e1a9142f09423a1f25819d14596586238b4310f8ac",
  "url": "https://osv.dev/vulnerability/CVE-2026-31445",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "mm/damon/core: avoid use of half-online-committed context",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: avoid use of half-online-committed context One major usage of damon_call() is online DAMON parameters update. It is done by calling damon_commit_ctx() inside the damon_call() callback function. damon_commit_ctx() can fail for two reasons: 1) invalid parameters and 2) internal memory allocation failures. In case of failures, the damon_ctx that attempted to be updated (commit destination) can be partially updated (or, corrupted from a perspective), and therefore shouldn't be used anymore. The function only ensures the damon_ctx object can safely deallocated using damon_destroy_ctx(). The API callers are, however, calling damon_commit_ctx() only after asserting the parameters are valid, to avoid damon_commit_ctx() fails due to invalid input parameters. But it can still theoretically fail if the internal memory allocation fails. In the case, DAMON may run with the partially updated damon_ctx. This can result in unexpected behaviors including even NULL pointer dereference in case of damos_commit_dests() failure [1]. Such allocation failure is arguably too small to fail, so the real world impact would be rare. But, given the bad consequence, this needs to be fixed. Avoid such partially-committed (maybe-corrupted) damon_ctx use by saving the damon_commit_ctx() failure on the damon_ctx object. For this, introduce damon_ctx->maybe_corrupted field. damon_commit_ctx() sets it when it is failed. kdamond_ca",
    "evidence": "osv:CVE-2026-31445",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.21",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.19.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-31445",
      "aliases": [
        "CVE-2026-31445"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "3301f1861d34f53911a30a8f5f41b9141bd8ed39"
                },
                {
                  "fixed": "9c495f9d3781cd692bd199531cabd4627155e8cd"
                },
                {
                  "fixed": "1b247cd0654a3a306996fa80741d79296c683a56"
                },
                {
                  "fixed": "26f775a054c3cda86ad465a64141894a90a9e145"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31445.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.15.0"
                },
                {
                  "fixed": "6.18.21"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "6.19.11"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31445.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.861283740Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/1b247cd0654a3a306996fa80741d79296c683a56",
        "https://git.kernel.org/stable/c/26f775a054c3cda86ad465a64141894a90a9e145",
        "https://git.kernel.org/stable/c/9c495f9d3781cd692bd199531cabd4627155e8cd",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31445.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-31445",
        "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/2026/31xxx/CVE-2026-31445.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-31445",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 505958,
  "published_at": "2026-04-22T13:53:42.09+00:00"
}