Vulnerability-Lookup

GHSA-QMFH-WQC6-R6C2

Vulnerability from github – Published: 2026-08-28 09:31 – Updated: 2026-08-28 09:31

Details

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

erofs: ensure valid f_path for page cache sharing

Previously, backing files for page cache sharing were set up with f_path left as NULL (only f_inode was valid). It worked, but a recent mincore fix relies on f_path.mnt and crashes (found by "erofs/028" on 7.2-rc4):

BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy) Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 RIP: 0010:__do_sys_mincore+0xc0/0x2c0 ...

Specify valid paths using valid disconnected dentries together with erofs_ishare_mnt instead of leaving f_path empty, so they are more like real backing files in a pseudo filesystem and standard backing_file_open() can be used directly.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-80697"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-28T08:16:55Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: ensure valid f_path for page cache sharing\n\nPreviously, backing files for page cache sharing were set up with\nf_path left as NULL (only f_inode was valid).  It worked, but a recent\nmincore fix relies on f_path.mnt and crashes (found by \"erofs/028\" on\n7.2-rc4):\n\n BUG: kernel NULL pointer dereference, address: 0000000000000018\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP PTI\n CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy)\n Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014\n RIP: 0010:__do_sys_mincore+0xc0/0x2c0\n ...\n\nSpecify valid paths using valid disconnected dentries together with\nerofs_ishare_mnt instead of leaving f_path empty, so they are more\nlike real backing files in a pseudo filesystem and standard\nbacking_file_open() can be used directly.",
  "id": "GHSA-qmfh-wqc6-r6c2",
  "modified": "2026-08-28T09:31:49Z",
  "published": "2026-08-28T09:31:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80697"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3879657c4ffd81b9a42cf575fc6cb60201032587"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-80697 (GCVE-0-2026-80697)

Vulnerability from cvelistv5 – Published: 2026-08-28 06:53 – Updated: 2026-08-28 12:08

Title

erofs: ensure valid f_path for page cache sharing

Summary

In the Linux kernel, the following vulnerability has been resolved: erofs: ensure valid f_path for page cache sharing Previously, backing files for page cache sharing were set up with f_path left as NULL (only f_inode was valid). It worked, but a recent mincore fix relies on f_path.mnt and crashes (found by "erofs/028" on 7.2-rc4): BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy) Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 RIP: 0010:__do_sys_mincore+0xc0/0x2c0 ... Specify valid paths using valid disconnected dentries together with erofs_ishare_mnt instead of leaving f_path empty, so they are more like real backing files in a pseudo filesystem and standard backing_file_open() can be used directly.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/3879657c4ffd81b9a…
https://git.kernel.org/stable/c/96b2dbbe58a1ea5df…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 5ef3208e3be50aa08b4e7a2832f34e16d42c08b3 , < 3879657c4ffd81b9a42cf575fc6cb60201032587 (git) Affected: 5ef3208e3be50aa08b4e7a2832f34e16d42c08b3 , < 96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443 (git)
Linux	Linux	Affected: 7.0 Unaffected: 0 , < 7.0 (semver) Unaffected: 7.1.8 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/erofs/Kconfig",
            "fs/erofs/internal.h",
            "fs/erofs/ishare.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3879657c4ffd81b9a42cf575fc6cb60201032587",
              "status": "affected",
              "version": "5ef3208e3be50aa08b4e7a2832f34e16d42c08b3",
              "versionType": "git"
            },
            {
              "lessThan": "96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443",
              "status": "affected",
              "version": "5ef3208e3be50aa08b4e7a2832f34e16d42c08b3",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/erofs/Kconfig",
            "fs/erofs/internal.h",
            "fs/erofs/ishare.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "lessThan": "7.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.8",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: ensure valid f_path for page cache sharing\n\nPreviously, backing files for page cache sharing were set up with\nf_path left as NULL (only f_inode was valid).  It worked, but a recent\nmincore fix relies on f_path.mnt and crashes (found by \"erofs/028\" on\n7.2-rc4):\n\n BUG: kernel NULL pointer dereference, address: 0000000000000018\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP PTI\n CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy)\n Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014\n RIP: 0010:__do_sys_mincore+0xc0/0x2c0\n ...\n\nSpecify valid paths using valid disconnected dentries together with\nerofs_ishare_mnt instead of leaving f_path empty, so they are more\nlike real backing files in a pseudo filesystem and standard\nbacking_file_open() can be used directly."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-28T12:08:17.218Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3879657c4ffd81b9a42cf575fc6cb60201032587"
        },
        {
          "url": "https://git.kernel.org/stable/c/96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443"
        }
      ],
      "title": "erofs: ensure valid f_path for page cache sharing",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80697",
    "datePublished": "2026-08-28T06:53:02.236Z",
    "dateReserved": "2026-08-26T14:34:25.786Z",
    "dateUpdated": "2026-08-28T12:08:17.218Z",
    "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.

Action not permitted

GHSA-QMFH-WQC6-R6C2

CVE-2026-80697 (GCVE-0-2026-80697)

Tags

Sightings

Nomenclature