Vulnerability-Lookup

CVE-2026-43388 (GCVE-0-2026-43388)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:21 – Updated: 2026-05-08 14:21

Title

mm/damon/core: clear walk_control on inactive context in damos_walk()

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: clear walk_control on inactive context in damos_walk() damos_walk() sets ctx->walk_control to the caller-provided control structure before checking whether the context is running. If the context is inactive (damon_is_running() returns false), the function returns -EINVAL without clearing ctx->walk_control. This leaves a dangling pointer to a stack-allocated structure that will be freed when the caller returns. This is structurally identical to the bug fixed in commit f9132fbc2e83 ("mm/damon/core: remove call_control in inactive contexts") for damon_call(), which had the same pattern of linking a control object and returning an error without unlinking it. The dangling walk_control pointer can cause: 1. Use-after-free if the context is later started and kdamond dereferences ctx->walk_control (e.g., in damos_walk_cancel() which writes to control->canceled and calls complete()) 2. Permanent -EBUSY from subsequent damos_walk() calls, since the stale pointer is non-NULL Nonetheless, the real user impact is quite restrictive. The use-after-free is impossible because there is no damos_walk() callers who starts the context later. The permanent -EBUSY can actually confuse users, as DAMON is not running. But the symptom is kept only while the context is turned off. Turning it on again will make DAMON internally uses a newly generated damon_ctx object that doesn't have the invalid damos_walk_control pointer, so everything will work fine again. Fix this by clearing ctx->walk_control under walk_control_lock before returning -EINVAL, mirroring the fix pattern from f9132fbc2e83.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/ce0aa47c963b8c3e5…
	https://git.kernel.org/stable/c/9320c77134ab8d770…
	https://git.kernel.org/stable/c/d210fdcac9c0d1380…

Impacted products

Vendor

Product

Version

Linux

Affected: bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61 , < ce0aa47c963b8c3e5beace89e2b5a665a64b5b6b (git)
Affected: bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61 , < 9320c77134ab8d7701e20608bbf08517df4fa321 (git)
Affected: bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61 , < d210fdcac9c0d1380eab448aebc93f602c1cd4e6 (git)

Linux

Affected: 6.14
Unaffected: 0 , < 6.14 (semver)
Unaffected: 6.18.19 , ≤ 6.18.* (semver)
Unaffected: 6.19.9 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "mm/damon/core.c"
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          "vendor": "Linux",
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              "versionType": "git"
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            {
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              "version": "bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61",
              "versionType": "git"
            },
            {
              "lessThan": "d210fdcac9c0d1380eab448aebc93f602c1cd4e6",
              "status": "affected",
              "version": "bf0eaba0ff9c9c8e6fd58ddfa1a8b6df4b813f61",
              "versionType": "git"
            }
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          "product": "Linux",
          "programFiles": [
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          ],
          "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": "6.18.*",
              "status": "unaffected",
              "version": "6.18.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.19",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.9",
                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "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: clear walk_control on inactive context in damos_walk()\n\ndamos_walk() sets ctx-\u003ewalk_control to the caller-provided control\nstructure before checking whether the context is running.  If the context\nis inactive (damon_is_running() returns false), the function returns\n-EINVAL without clearing ctx-\u003ewalk_control.  This leaves a dangling\npointer to a stack-allocated structure that will be freed when the caller\nreturns.\n\nThis is structurally identical to the bug fixed in commit f9132fbc2e83\n(\"mm/damon/core: remove call_control in inactive contexts\") for\ndamon_call(), which had the same pattern of linking a control object and\nreturning an error without unlinking it.\n\nThe dangling walk_control pointer can cause:\n1. Use-after-free if the context is later started and kdamond\n\u00a0 \u00a0dereferences ctx-\u003ewalk_control (e.g., in damos_walk_cancel()\n\u00a0 \u00a0which writes to control-\u003ecanceled and calls complete())\n2. Permanent -EBUSY from subsequent damos_walk() calls, since the\n\u00a0 \u00a0stale pointer is non-NULL\n\nNonetheless, the real user impact is quite restrictive.  The\nuse-after-free is impossible because there is no damos_walk() callers who\nstarts the context later.  The permanent -EBUSY can actually confuse\nusers, as DAMON is not running.  But the symptom is kept only while the\ncontext is turned off.  Turning it on again will make DAMON internally\nuses a newly generated damon_ctx object that doesn\u0027t have the invalid\ndamos_walk_control pointer, so everything will work fine again.\n\nFix this by clearing ctx-\u003ewalk_control under walk_control_lock before\nreturning -EINVAL, mirroring the fix pattern from f9132fbc2e83."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-08T14:21:33.966Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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        },
        {
          "url": "https://git.kernel.org/stable/c/9320c77134ab8d7701e20608bbf08517df4fa321"
        },
        {
          "url": "https://git.kernel.org/stable/c/d210fdcac9c0d1380eab448aebc93f602c1cd4e6"
        }
      ],
      "title": "mm/damon/core: clear walk_control on inactive context in damos_walk()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43388",
    "datePublished": "2026-05-08T14:21:33.966Z",
    "dateReserved": "2026-05-01T14:12:56.006Z",
    "dateUpdated": "2026-05-08T14:21:33.966Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-43388\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-08T15:16:50.180\",\"lastModified\":\"2026-05-08T15:16:50.180\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nmm/damon/core: clear walk_control on inactive context in damos_walk()\\n\\ndamos_walk() sets ctx-\u003ewalk_control to the caller-provided control\\nstructure before checking whether the context is running.  If the context\\nis inactive (damon_is_running() returns false), the function returns\\n-EINVAL without clearing ctx-\u003ewalk_control.  This leaves a dangling\\npointer to a stack-allocated structure that will be freed when the caller\\nreturns.\\n\\nThis is structurally identical to the bug fixed in commit f9132fbc2e83\\n(\\\"mm/damon/core: remove call_control in inactive contexts\\\") for\\ndamon_call(), which had the same pattern of linking a control object and\\nreturning an error without unlinking it.\\n\\nThe dangling walk_control pointer can cause:\\n1. Use-after-free if the context is later started and kdamond\\n\u00a0 \u00a0dereferences ctx-\u003ewalk_control (e.g., in damos_walk_cancel()\\n\u00a0 \u00a0which writes to control-\u003ecanceled and calls complete())\\n2. Permanent -EBUSY from subsequent damos_walk() calls, since the\\n\u00a0 \u00a0stale pointer is non-NULL\\n\\nNonetheless, the real user impact is quite restrictive.  The\\nuse-after-free is impossible because there is no damos_walk() callers who\\nstarts the context later.  The permanent -EBUSY can actually confuse\\nusers, as DAMON is not running.  But the symptom is kept only while the\\ncontext is turned off.  Turning it on again will make DAMON internally\\nuses a newly generated damon_ctx object that doesn\u0027t have the invalid\\ndamos_walk_control pointer, so everything will work fine again.\\n\\nFix this by clearing ctx-\u003ewalk_control under walk_control_lock before\\nreturning -EINVAL, mirroring the fix pattern from f9132fbc2e83.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/9320c77134ab8d7701e20608bbf08517df4fa321\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ce0aa47c963b8c3e5beace89e2b5a665a64b5b6b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d210fdcac9c0d1380eab448aebc93f602c1cd4e6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}

FKIE_CVE-2026-43388

Vulnerability from fkie_nvd - Published: 2026-05-08 15:16 - Updated: 2026-05-08 15:16

Severity ?

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9320c77134ab8d7701e20608bbf08517df4fa321
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ce0aa47c963b8c3e5beace89e2b5a665a64b5b6b
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d210fdcac9c0d1380eab448aebc93f602c1cd4e6

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: clear walk_control on inactive context in damos_walk()\n\ndamos_walk() sets ctx-\u003ewalk_control to the caller-provided control\nstructure before checking whether the context is running.  If the context\nis inactive (damon_is_running() returns false), the function returns\n-EINVAL without clearing ctx-\u003ewalk_control.  This leaves a dangling\npointer to a stack-allocated structure that will be freed when the caller\nreturns.\n\nThis is structurally identical to the bug fixed in commit f9132fbc2e83\n(\"mm/damon/core: remove call_control in inactive contexts\") for\ndamon_call(), which had the same pattern of linking a control object and\nreturning an error without unlinking it.\n\nThe dangling walk_control pointer can cause:\n1. Use-after-free if the context is later started and kdamond\n\u00a0 \u00a0dereferences ctx-\u003ewalk_control (e.g., in damos_walk_cancel()\n\u00a0 \u00a0which writes to control-\u003ecanceled and calls complete())\n2. Permanent -EBUSY from subsequent damos_walk() calls, since the\n\u00a0 \u00a0stale pointer is non-NULL\n\nNonetheless, the real user impact is quite restrictive.  The\nuse-after-free is impossible because there is no damos_walk() callers who\nstarts the context later.  The permanent -EBUSY can actually confuse\nusers, as DAMON is not running.  But the symptom is kept only while the\ncontext is turned off.  Turning it on again will make DAMON internally\nuses a newly generated damon_ctx object that doesn\u0027t have the invalid\ndamos_walk_control pointer, so everything will work fine again.\n\nFix this by clearing ctx-\u003ewalk_control under walk_control_lock before\nreturning -EINVAL, mirroring the fix pattern from f9132fbc2e83."
    }
  ],
  "id": "CVE-2026-43388",
  "lastModified": "2026-05-08T15:16:50.180",
  "metrics": {},
  "published": "2026-05-08T15:16:50.180",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9320c77134ab8d7701e20608bbf08517df4fa321"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ce0aa47c963b8c3e5beace89e2b5a665a64b5b6b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d210fdcac9c0d1380eab448aebc93f602c1cd4e6"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-C2GP-49Q2-6JXP

Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-08 15:31

Details

In the Linux kernel, the following vulnerability has been resolved:

mm/damon/core: clear walk_control on inactive context in damos_walk()

damos_walk() sets ctx->walk_control to the caller-provided control structure before checking whether the context is running. If the context is inactive (damon_is_running() returns false), the function returns -EINVAL without clearing ctx->walk_control. This leaves a dangling pointer to a stack-allocated structure that will be freed when the caller returns.

This is structurally identical to the bug fixed in commit f9132fbc2e83 ("mm/damon/core: remove call_control in inactive contexts") for damon_call(), which had the same pattern of linking a control object and returning an error without unlinking it.

The dangling walk_control pointer can cause: 1. Use-after-free if the context is later started and kdamond dereferences ctx->walk_control (e.g., in damos_walk_cancel() which writes to control->canceled and calls complete()) 2. Permanent -EBUSY from subsequent damos_walk() calls, since the stale pointer is non-NULL

Nonetheless, the real user impact is quite restrictive. The use-after-free is impossible because there is no damos_walk() callers who starts the context later. The permanent -EBUSY can actually confuse users, as DAMON is not running. But the symptom is kept only while the context is turned off. Turning it on again will make DAMON internally uses a newly generated damon_ctx object that doesn't have the invalid damos_walk_control pointer, so everything will work fine again.

Fix this by clearing ctx->walk_control under walk_control_lock before returning -EINVAL, mirroring the fix pattern from f9132fbc2e83.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-43388"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-08T15:16:50Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/core: clear walk_control on inactive context in damos_walk()\n\ndamos_walk() sets ctx-\u003ewalk_control to the caller-provided control\nstructure before checking whether the context is running.  If the context\nis inactive (damon_is_running() returns false), the function returns\n-EINVAL without clearing ctx-\u003ewalk_control.  This leaves a dangling\npointer to a stack-allocated structure that will be freed when the caller\nreturns.\n\nThis is structurally identical to the bug fixed in commit f9132fbc2e83\n(\"mm/damon/core: remove call_control in inactive contexts\") for\ndamon_call(), which had the same pattern of linking a control object and\nreturning an error without unlinking it.\n\nThe dangling walk_control pointer can cause:\n1. Use-after-free if the context is later started and kdamond\n\u00a0 \u00a0dereferences ctx-\u003ewalk_control (e.g., in damos_walk_cancel()\n\u00a0 \u00a0which writes to control-\u003ecanceled and calls complete())\n2. Permanent -EBUSY from subsequent damos_walk() calls, since the\n\u00a0 \u00a0stale pointer is non-NULL\n\nNonetheless, the real user impact is quite restrictive.  The\nuse-after-free is impossible because there is no damos_walk() callers who\nstarts the context later.  The permanent -EBUSY can actually confuse\nusers, as DAMON is not running.  But the symptom is kept only while the\ncontext is turned off.  Turning it on again will make DAMON internally\nuses a newly generated damon_ctx object that doesn\u0027t have the invalid\ndamos_walk_control pointer, so everything will work fine again.\n\nFix this by clearing ctx-\u003ewalk_control under walk_control_lock before\nreturning -EINVAL, mirroring the fix pattern from f9132fbc2e83.",
  "id": "GHSA-c2gp-49q2-6jxp",
  "modified": "2026-05-08T15:31:27Z",
  "published": "2026-05-08T15:31:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43388"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9320c77134ab8d7701e20608bbf08517df4fa321"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ce0aa47c963b8c3e5beace89e2b5a665a64b5b6b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d210fdcac9c0d1380eab448aebc93f602c1cd4e6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

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

CVE-2026-43388 (GCVE-0-2026-43388)

FKIE_CVE-2026-43388

GHSA-C2GP-49Q2-6JXP

Tags

Sightings

Nomenclature