Vulnerability-Lookup

FKIE_CVE-2026-80778

Vulnerability from fkie_nvd - Published: 2026-09-04 16:18 - Updated: 2026-09-04 16:18

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: futex/pi: Reject cross-mm private futex owners A private futex key borrows the waiter's mm without taking an mm_users reference. Nevertheless, attach_to_pi_owner() currently accepts an owner from a different address space and copies the private key into the owner's PI state. When that owner exits, exit_pi_state_list() uses the saved key to find the hash bucket and acquires a reference to the waiter's private hash. If the last user of the waiter's mm exits concurrently, futex_hash_free() frees the hash while the owner still uses its bucket and reference. Prevent this by validating in attach_to_pi_owner() that, for private futexes, the owner mm and waiter mm are the same. Perform the check with the owner's pi_lock held and after validating owner::futex::state to serialize against a concurrent PI-state exit cleanup. [ tglx: Amended comment ]

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2b92e5562653b5293529f63b0300837d9dcedbd7
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/43b148d796aa338858792d0167cebdc12b8cb4b9
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/59b3732f95dda1fbd2234514d35f4fb6b5bb6d85
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f7fb3e07752688842cbe0b85cf0d98c2fbf76b68

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/futex/pi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2b92e5562653b5293529f63b0300837d9dcedbd7",
              "status": "affected",
              "version": "80367ad01d93ac781b0e1df246edaf006928002f",
              "versionType": "git"
            },
            {
              "lessThan": "f7fb3e07752688842cbe0b85cf0d98c2fbf76b68",
              "status": "affected",
              "version": "80367ad01d93ac781b0e1df246edaf006928002f",
              "versionType": "git"
            },
            {
              "lessThan": "43b148d796aa338858792d0167cebdc12b8cb4b9",
              "status": "affected",
              "version": "80367ad01d93ac781b0e1df246edaf006928002f",
              "versionType": "git"
            },
            {
              "lessThan": "59b3732f95dda1fbd2234514d35f4fb6b5bb6d85",
              "status": "affected",
              "version": "80367ad01d93ac781b0e1df246edaf006928002f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/futex/pi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.47",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex/pi: Reject cross-mm private futex owners\n\nA private futex key borrows the waiter\u0027s mm without taking an mm_users\nreference. Nevertheless, attach_to_pi_owner() currently accepts an owner\nfrom a different address space and copies the private key into the owner\u0027s\nPI state.\n\nWhen that owner exits, exit_pi_state_list() uses the saved key to find the\nhash bucket and acquires a reference to the waiter\u0027s private hash. If the\nlast user of the waiter\u0027s mm exits concurrently, futex_hash_free() frees\nthe hash while the owner still uses its bucket and reference.\n\nPrevent this by validating in attach_to_pi_owner() that, for private\nfutexes, the owner mm and waiter mm are the same. Perform the check with\nthe owner\u0027s pi_lock held and after validating owner::futex::state to\nserialize against a concurrent PI-state exit cleanup.\n\n[ tglx: Amended comment ]"
    }
  ],
  "id": "CVE-2026-80778",
  "lastModified": "2026-09-04T16:18:03.490",
  "metrics": {},
  "published": "2026-09-04T16:18:03.490",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2b92e5562653b5293529f63b0300837d9dcedbd7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/43b148d796aa338858792d0167cebdc12b8cb4b9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/59b3732f95dda1fbd2234514d35f4fb6b5bb6d85"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f7fb3e07752688842cbe0b85cf0d98c2fbf76b68"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-80778 (GCVE-0-2026-80778)

Vulnerability from cvelistv5 – Published: 2026-09-04 15:12 – Updated: 2026-09-04 15:12

Title

futex/pi: Reject cross-mm private futex owners

Summary

Severity

No CVSS data available.

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/2b92e5562653b5293…
https://git.kernel.org/stable/c/f7fb3e07752688842…
https://git.kernel.org/stable/c/43b148d796aa33885…
https://git.kernel.org/stable/c/59b3732f95dda1fbd…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 80367ad01d93ac781b0e1df246edaf006928002f , < 2b92e5562653b5293529f63b0300837d9dcedbd7 (git) Affected: 80367ad01d93ac781b0e1df246edaf006928002f , < f7fb3e07752688842cbe0b85cf0d98c2fbf76b68 (git) Affected: 80367ad01d93ac781b0e1df246edaf006928002f , < 43b148d796aa338858792d0167cebdc12b8cb4b9 (git) Affected: 80367ad01d93ac781b0e1df246edaf006928002f , < 59b3732f95dda1fbd2234514d35f4fb6b5bb6d85 (git)
Linux	Linux	Affected: 6.16 Unaffected: 0 , < 6.16 (semver) Unaffected: 6.18.47 , ≤ 6.18.* (semver) Unaffected: 7.1.11 , ≤ 7.1.* (semver) Unaffected: 7.2.1 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/futex/pi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2b92e5562653b5293529f63b0300837d9dcedbd7",
              "status": "affected",
              "version": "80367ad01d93ac781b0e1df246edaf006928002f",
              "versionType": "git"
            },
            {
              "lessThan": "f7fb3e07752688842cbe0b85cf0d98c2fbf76b68",
              "status": "affected",
              "version": "80367ad01d93ac781b0e1df246edaf006928002f",
              "versionType": "git"
            },
            {
              "lessThan": "43b148d796aa338858792d0167cebdc12b8cb4b9",
              "status": "affected",
              "version": "80367ad01d93ac781b0e1df246edaf006928002f",
              "versionType": "git"
            },
            {
              "lessThan": "59b3732f95dda1fbd2234514d35f4fb6b5bb6d85",
              "status": "affected",
              "version": "80367ad01d93ac781b0e1df246edaf006928002f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/futex/pi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.47",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.47",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.11",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.1",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex/pi: Reject cross-mm private futex owners\n\nA private futex key borrows the waiter\u0027s mm without taking an mm_users\nreference. Nevertheless, attach_to_pi_owner() currently accepts an owner\nfrom a different address space and copies the private key into the owner\u0027s\nPI state.\n\nWhen that owner exits, exit_pi_state_list() uses the saved key to find the\nhash bucket and acquires a reference to the waiter\u0027s private hash. If the\nlast user of the waiter\u0027s mm exits concurrently, futex_hash_free() frees\nthe hash while the owner still uses its bucket and reference.\n\nPrevent this by validating in attach_to_pi_owner() that, for private\nfutexes, the owner mm and waiter mm are the same. Perform the check with\nthe owner\u0027s pi_lock held and after validating owner::futex::state to\nserialize against a concurrent PI-state exit cleanup.\n\n[ tglx: Amended comment ]"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-04T15:12:50.117Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/2b92e5562653b5293529f63b0300837d9dcedbd7"
        },
        {
          "url": "https://git.kernel.org/stable/c/f7fb3e07752688842cbe0b85cf0d98c2fbf76b68"
        },
        {
          "url": "https://git.kernel.org/stable/c/43b148d796aa338858792d0167cebdc12b8cb4b9"
        },
        {
          "url": "https://git.kernel.org/stable/c/59b3732f95dda1fbd2234514d35f4fb6b5bb6d85"
        }
      ],
      "title": "futex/pi: Reject cross-mm private futex owners",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80778",
    "datePublished": "2026-09-04T15:12:50.117Z",
    "dateReserved": "2026-08-26T14:34:25.792Z",
    "dateUpdated": "2026-09-04T15:12:50.117Z",
    "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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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