FKIE_CVE-2026-64600

Vulnerability from fkie_nvd - Published: 2026-07-23 06:16 - Updated: 2026-07-23 08:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: xfs: resample the data fork mapping after cycling ILOCK xfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode, a data fork mapping, and a cow fork mapping. Unfortunately, these two helpers cycle the ILOCK to grab a transaction, which means that the mappings are stale as soon as we reacquire the ILOCK. Currently we refresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but we don't refresh the data fork mapping beforehand, which means that the xfs_bmap_trim_cow in that function queries the refcount btree about the wrong physical blocks and returns an inaccurate value in *shared. If *shared is now false, the directio write proceeds with a stale data fork mapping. Fix this by querying the data fork mapping if the sequence counter changes across the ILOCK cycle.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/206c09b04dc5469c7ff14d8aceff2d47c88078d9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/44f891bc088958399eec27f7604928694aa35581
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e705d81a7193dd19e69b8e2bad4696d78a4ea075
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/07/22/14
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/07/22/18
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/07/22/19
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/xfs/xfs_reflink.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e705d81a7193dd19e69b8e2bad4696d78a4ea075",
              "status": "affected",
              "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5",
              "versionType": "git"
            },
            {
              "lessThan": "206c09b04dc5469c7ff14d8aceff2d47c88078d9",
              "status": "affected",
              "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5",
              "versionType": "git"
            },
            {
              "lessThan": "44f891bc088958399eec27f7604928694aa35581",
              "status": "affected",
              "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5",
              "versionType": "git"
            },
            {
              "lessThan": "2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7",
              "status": "affected",
              "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/xfs/xfs_reflink.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.11"
            },
            {
              "lessThan": "4.11",
              "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": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc4",
              "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\nxfs: resample the data fork mapping after cycling ILOCK\n\nxfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode,\na data fork mapping, and a cow fork mapping.  Unfortunately, these two\nhelpers cycle the ILOCK to grab a transaction, which means that the\nmappings are stale as soon as we reacquire the ILOCK.  Currently we\nrefresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but\nwe don\u0027t refresh the data fork mapping beforehand, which means that the\nxfs_bmap_trim_cow in that function queries the refcount btree about the\nwrong physical blocks and returns an inaccurate value in *shared.\n\nIf *shared is now false, the directio write proceeds with a stale data\nfork mapping.  Fix this by querying the data fork mapping if the\nsequence counter changes across the ILOCK cycle."
    }
  ],
  "id": "CVE-2026-64600",
  "lastModified": "2026-07-23T08:16:25.140",
  "metrics": {},
  "published": "2026-07-23T06:16:50.493",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/206c09b04dc5469c7ff14d8aceff2d47c88078d9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/44f891bc088958399eec27f7604928694aa35581"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e705d81a7193dd19e69b8e2bad4696d78a4ea075"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/07/22/14"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/07/22/18"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/07/22/19"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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