FKIE_CVE-2026-63816

Vulnerability from fkie_nvd - Published: 2026-07-19 12:16 - Updated: 2026-07-20 15:16
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode - ioctl(F2FS_IOC_GARBAGE_COLLECT_RANGE) - shrink - f2fs_gc - gc_data_segment - ra_data_block(cow_inode) - mapping = F2FS_I(inode)->atomic_inode->i_mapping : f2fs_is_cow_file(cow_inode) is true - f2fs_evict_inode(atomic_inode) - clear_inode_flag(fi->cow_inode, FI_COW_FILE) - F2FS_I(fi->cow_inode)->atomic_inode = NULL ... - truncate_inode_pages_final(atomic_inode) - f2fs_grab_cache_folio(mapping) : create folio in atomic_inode->mapping - clear_inode(atomic_inode) - BUG_ON(atomic_inode->i_data.nrpages) We need to add a reference on fi->atomic_inode before using its mapping field during garbage collection, otherwise, it will cause UAF issue.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/56038756aae68312df00d4aa1d97e51ef3aca725
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a499f77c06050a28c897bdbd86cd2f0721ae0743
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a805fec35c201c59643ddcde713bce4051c8ee27
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e0288584baa5dc41df4a829a023c4c1b33fe53d7
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/gc.c",
            "fs/f2fs/inode.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "56038756aae68312df00d4aa1d97e51ef3aca725",
              "status": "affected",
              "version": "3db1de0e582c358dd013f3703cd55b5fe4076436",
              "versionType": "git"
            },
            {
              "lessThan": "a499f77c06050a28c897bdbd86cd2f0721ae0743",
              "status": "affected",
              "version": "3db1de0e582c358dd013f3703cd55b5fe4076436",
              "versionType": "git"
            },
            {
              "lessThan": "a805fec35c201c59643ddcde713bce4051c8ee27",
              "status": "affected",
              "version": "3db1de0e582c358dd013f3703cd55b5fe4076436",
              "versionType": "git"
            },
            {
              "lessThan": "e0288584baa5dc41df4a829a023c4c1b33fe53d7",
              "status": "affected",
              "version": "3db1de0e582c358dd013f3703cd55b5fe4076436",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6db52f1944417c2601182a591a704e2f119c5215",
              "versionType": "git"
            },
            {
              "lessThan": "5.19",
              "status": "affected",
              "version": "5.18.18",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/gc.c",
            "fs/f2fs/inode.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-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\nf2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode\n\n- ioctl(F2FS_IOC_GARBAGE_COLLECT_RANGE)\t\t- shrink\n - f2fs_gc\n  - gc_data_segment\n   - ra_data_block(cow_inode)\n    - mapping = F2FS_I(inode)-\u003eatomic_inode-\u003ei_mapping\n    : f2fs_is_cow_file(cow_inode) is true\n\t\t\t\t\t\t - f2fs_evict_inode(atomic_inode)\n\t\t\t\t\t\t  - clear_inode_flag(fi-\u003ecow_inode, FI_COW_FILE)\n\t\t\t\t\t\t  - F2FS_I(fi-\u003ecow_inode)-\u003eatomic_inode = NULL\n\t\t\t\t\t\t  ...\n\t\t\t\t\t\t  - truncate_inode_pages_final(atomic_inode)\n    - f2fs_grab_cache_folio(mapping)\n    : create folio in atomic_inode-\u003emapping\n\t\t\t\t\t\t  - clear_inode(atomic_inode)\n\t\t\t\t\t\t   - BUG_ON(atomic_inode-\u003ei_data.nrpages)\n\nWe need to add a reference on fi-\u003eatomic_inode before using its mapping\nfield during garbage collection, otherwise, it will cause UAF issue."
    }
  ],
  "id": "CVE-2026-63816",
  "lastModified": "2026-07-20T15:16:48.467",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T12:16:54.643",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/56038756aae68312df00d4aa1d97e51ef3aca725"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a499f77c06050a28c897bdbd86cd2f0721ae0743"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a805fec35c201c59643ddcde713bce4051c8ee27"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e0288584baa5dc41df4a829a023c4c1b33fe53d7"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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