mm/damon/core: fix damon_call() vs kdamond_fn() exit race

{
  "id": "8c61563f7c2f582f2cf0f2b84fc8dec0a3d3fdbcd84f1256f93ae29bfdac5c5a",
  "url": "https://osv.dev/vulnerability/CVE-2026-46025",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "mm/damon/core: fix damon_call() vs kdamond_fn() exit race",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: fix damon_call() vs kdamond_fn() exit race Patch series \"mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit race\". damon_call() and damos_walk() can leak memory and/or deadlock when they race with kdamond terminations. Fix those. This patch (of 2); When kdamond_fn() main loop is finished, the function cancels all remaining damon_call() requests and unset the damon_ctx->kdamond so that API callers and API functions themselves can know the context is terminated. damon_call() adds the caller's request to the queue first. After that, it shows if the kdamond of the damon_ctx is still running (damon_ctx->kdamond is set). Only if the kdamond is running, damon_call() starts waiting for the kdamond's handling of the newly added request. The damon_call() requests registration and damon_ctx->kdamond unset are protected by different mutexes, though. Hence, damon_call() could race with damon_ctx->kdamond unset, and result in deadlocks. For example, let's suppose kdamond successfully finished the damon_call() requests cancelling. Right after that, damon_call() is called for the context. It registers the new request, and shows the context is still running, because damon_ctx->kdamond unset is not yet done. Hence the damon_call() caller starts waiting for the handling of the request. However, the kdamond is already on the termination steps, so it never handles the new request. As a result, the damon_ca",
    "evidence": "osv:CVE-2026-46025",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.27",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-46025",
      "aliases": [
        "CVE-2026-46025"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "42b7491af14cbba2393329ce43d508a957bd94fa"
                },
                {
                  "fixed": "2691332ad88b57179c38653e2cd613d5820a52cf"
                },
                {
                  "fixed": "e6a053a6f4b5048746c49432a5cc5b79fe4695fe"
                },
                {
                  "fixed": "55da81663b9642dd046b26dd6f1baddbcf337c1e"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46025.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.14.0"
                },
                {
                  "fixed": "6.18.27"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46025.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.644849208Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/2691332ad88b57179c38653e2cd613d5820a52cf",
        "https://git.kernel.org/stable/c/55da81663b9642dd046b26dd6f1baddbcf337c1e",
        "https://git.kernel.org/stable/c/e6a053a6f4b5048746c49432a5cc5b79fe4695fe",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46025.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-46025",
        "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/2026/46xxx/CVE-2026-46025.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-46025",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 507872,
  "published_at": "2026-05-27T12:56:31.784+00:00"
}