Vulnerability-Lookup

FKIE_CVE-2026-46008

Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-05-27 14:48

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: fix damos_walk() vs kdamond_fn() exit race When kdamond_fn() main loop is finished, the function cancels remaining damos_walk() request and unset the damon_ctx->kdamond so that API callers and API functions themselves can show the context is terminated. damos_walk() 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, damos_walk() starts waiting for the kdamond's handling of the newly added request. The damos_walk() requests registration and damon_ctx->kdamond unset are protected by different mutexes, though. Hence, damos_walk() could race with damon_ctx->kdamond unset, and result in deadlocks. For example, let's suppose kdamond successfully finished the damow_walk() request cancelling. Right after that, damos_walk() 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 damos_walk() 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 damos_walk() caller thread infinitely waits. Fix this by introducing another damon_ctx field, namely walk_control_obsolete. It is protected by the damon_ctx->walk_control_lock, which protects damos_walk() request registration. Initialize (unset) it in kdamond_fn() before letting damon_start() returns and set it just before the cancelling of the remaining damos_walk() request is executed. damos_walk() reads the obsolete field under the lock and avoids adding a new request. After this change, only requests that are guaranteed to be handled or cancelled are registered. Hence the after-registration DAMON context termination check is no longer needed. Remove it together. The issue is found by sashiko [1].

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0ba956a239ba6e3fae8555d3660e22e675be63b5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/33c3f6c2b48cd84b441dba1ee3e62290e53930f4

Impacted products

	Vendor	Product	Version

JSON

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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: fix damos_walk() vs kdamond_fn() exit race\n\nWhen kdamond_fn() main loop is finished, the function cancels remaining\ndamos_walk() request and unset the damon_ctx-\u003ekdamond so that API callers\nand API functions themselves can show the context is terminated. \ndamos_walk() adds the caller\u0027s request to the queue first.  After that, it\nshows if the kdamond of the damon_ctx is still running (damon_ctx-\u003ekdamond\nis set).  Only if the kdamond is running, damos_walk() starts waiting for\nthe kdamond\u0027s handling of the newly added request.\n\nThe damos_walk() requests registration and damon_ctx-\u003ekdamond unset are\nprotected by different mutexes, though.  Hence, damos_walk() could race\nwith damon_ctx-\u003ekdamond unset, and result in deadlocks.\n\nFor example, let\u0027s suppose kdamond successfully finished the damow_walk()\nrequest cancelling.  Right after that, damos_walk() is called for the\ncontext.  It registers the new request, and shows the context is still\nrunning, because damon_ctx-\u003ekdamond unset is not yet done.  Hence the\ndamos_walk() caller starts waiting for the handling of the request. \nHowever, the kdamond is already on the termination steps, so it never\nhandles the new request.  As a result, the damos_walk() caller thread\ninfinitely waits.\n\nFix this by introducing another damon_ctx field, namely\nwalk_control_obsolete.  It is protected by the\ndamon_ctx-\u003ewalk_control_lock, which protects damos_walk() request\nregistration.  Initialize (unset) it in kdamond_fn() before letting\ndamon_start() returns and set it just before the cancelling of the\nremaining damos_walk() request is executed.  damos_walk() reads the\nobsolete field under the lock and avoids adding a new request.\n\nAfter this change, only requests that are guaranteed to be handled or\ncancelled are registered.  Hence the after-registration DAMON context\ntermination check is no longer needed.  Remove it together.\n\nThe issue is found by sashiko [1]."
    }
  ],
  "id": "CVE-2026-46008",
  "lastModified": "2026-05-27T14:48:03.013",
  "metrics": {},
  "published": "2026-05-27T14:17:18.600",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0ba956a239ba6e3fae8555d3660e22e675be63b5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/33c3f6c2b48cd84b441dba1ee3e62290e53930f4"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

CVE-2026-46008 (GCVE-0-2026-46008)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:56 – Updated: 2026-05-27 12:56

Title

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

Summary

Severity

No CVSS data available.

Assigner

Linux

References

2 references

URL	Tags
https://git.kernel.org/stable/c/0ba956a239ba6e3fa…
https://git.kernel.org/stable/c/33c3f6c2b48cd84b4…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61 , < 0ba956a239ba6e3fae8555d3660e22e675be63b5 (git) Affected: bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61 , < 33c3f6c2b48cd84b441dba1ee3e62290e53930f4 (git)
Linux	Linux	Affected: 6.14 Unaffected: 0 , < 6.14 (semver) Unaffected: 7.0.4 , ≤ 7.0.* (semver) Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/linux/damon.h",
            "mm/damon/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0ba956a239ba6e3fae8555d3660e22e675be63b5",
              "status": "affected",
              "version": "bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61",
              "versionType": "git"
            },
            {
              "lessThan": "33c3f6c2b48cd84b441dba1ee3e62290e53930f4",
              "status": "affected",
              "version": "bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/linux/damon.h",
            "mm/damon/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.14"
            },
            {
              "lessThan": "6.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.4",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1-rc1",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: fix damos_walk() vs kdamond_fn() exit race\n\nWhen kdamond_fn() main loop is finished, the function cancels remaining\ndamos_walk() request and unset the damon_ctx-\u003ekdamond so that API callers\nand API functions themselves can show the context is terminated. \ndamos_walk() adds the caller\u0027s request to the queue first.  After that, it\nshows if the kdamond of the damon_ctx is still running (damon_ctx-\u003ekdamond\nis set).  Only if the kdamond is running, damos_walk() starts waiting for\nthe kdamond\u0027s handling of the newly added request.\n\nThe damos_walk() requests registration and damon_ctx-\u003ekdamond unset are\nprotected by different mutexes, though.  Hence, damos_walk() could race\nwith damon_ctx-\u003ekdamond unset, and result in deadlocks.\n\nFor example, let\u0027s suppose kdamond successfully finished the damow_walk()\nrequest cancelling.  Right after that, damos_walk() is called for the\ncontext.  It registers the new request, and shows the context is still\nrunning, because damon_ctx-\u003ekdamond unset is not yet done.  Hence the\ndamos_walk() caller starts waiting for the handling of the request. \nHowever, the kdamond is already on the termination steps, so it never\nhandles the new request.  As a result, the damos_walk() caller thread\ninfinitely waits.\n\nFix this by introducing another damon_ctx field, namely\nwalk_control_obsolete.  It is protected by the\ndamon_ctx-\u003ewalk_control_lock, which protects damos_walk() request\nregistration.  Initialize (unset) it in kdamond_fn() before letting\ndamon_start() returns and set it just before the cancelling of the\nremaining damos_walk() request is executed.  damos_walk() reads the\nobsolete field under the lock and avoids adding a new request.\n\nAfter this change, only requests that are guaranteed to be handled or\ncancelled are registered.  Hence the after-registration DAMON context\ntermination check is no longer needed.  Remove it together.\n\nThe issue is found by sashiko [1]."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-27T12:56:08.315Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/0ba956a239ba6e3fae8555d3660e22e675be63b5"
        },
        {
          "url": "https://git.kernel.org/stable/c/33c3f6c2b48cd84b441dba1ee3e62290e53930f4"
        }
      ],
      "title": "mm/damon/core: fix damos_walk() vs kdamond_fn() exit race",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-46008",
    "datePublished": "2026-05-27T12:56:08.315Z",
    "dateReserved": "2026-05-13T15:03:33.092Z",
    "dateUpdated": "2026-05-27T12:56:08.315Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2026-46008

CVE-2026-46008 (GCVE-0-2026-46008)

Tags

Sightings

Nomenclature