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FKIE_CVE-2026-89723

Vulnerability from fkie_nvd - Published: 2026-09-11 20:20 - Updated: 2026-09-14 13:19
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: nilfs2: fix slab-out-of-bounds in nilfs_direct_propagate after truncation Shuangpeng Bai reported that KASAN detected a slab-out-of-bounds error in nilfs_direct_propagate() during testing. Analysis revealed that after truncating a file, a node block immediately below the B-tree root was not deleted. Instead, it remained in the B-tree node cache in a dirty state. The log writer subsequently detected this block and incorrectly invoked nilfs_direct_propagate() on it, which is designed to handle only data blocks in direct mapping. B-tree nodes in the cache are managed by virtual block numbers, and their logical keys typically exceed the range expected by direct mapping. Consequently, processing such a node as a direct mapping entry triggers a slab-out-of-bounds access. The root cause is that when a B-tree mapping collapses into a direct mapping during truncation, an intermediate node block pointed to by the root node is left behind as garbage instead of being explicitly deleted. This resolves the issue by adding a nilfs_btree_discard() operation to delete the remaining intermediate node block during the conversion. A 'deform' flag is added to the bop_delete interface to explicitly signal that the deletion is part of a mapping transformation. This allows the B-tree mapping implementation to perform the necessary cleanup and discarding of the residual node structure that would be otherwise be left orphaned after the transition.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/28362e8ce51377afdec1782e661e808328a10514
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/39005fd1ce654ffdecacddc406b9a038efe606e6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/448636c745a3f3b8582a0b8ce718c890a11c0fa9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/45662dedb8f272ef7f16e69f13424c4bd0399240
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4a1bb1f9f24a935c9b3f4fbf98012fa6d4ad826d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5d3783c451a546373662ee11ec17019273e68034
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b313edfbc0c2a60f7ce09b2e81ee71909ab8ddaf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bf49e6f6ddc12445a0330708b365de6458085980
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nilfs2/bmap.c",
            "fs/nilfs2/bmap.h",
            "fs/nilfs2/btree.c",
            "fs/nilfs2/direct.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "39005fd1ce654ffdecacddc406b9a038efe606e6",
              "status": "affected",
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "versionType": "git"
            },
            {
              "lessThan": "bf49e6f6ddc12445a0330708b365de6458085980",
              "status": "affected",
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "versionType": "git"
            },
            {
              "lessThan": "4a1bb1f9f24a935c9b3f4fbf98012fa6d4ad826d",
              "status": "affected",
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "versionType": "git"
            },
            {
              "lessThan": "b313edfbc0c2a60f7ce09b2e81ee71909ab8ddaf",
              "status": "affected",
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "versionType": "git"
            },
            {
              "lessThan": "5d3783c451a546373662ee11ec17019273e68034",
              "status": "affected",
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "versionType": "git"
            },
            {
              "lessThan": "448636c745a3f3b8582a0b8ce718c890a11c0fa9",
              "status": "affected",
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "versionType": "git"
            },
            {
              "lessThan": "28362e8ce51377afdec1782e661e808328a10514",
              "status": "affected",
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "versionType": "git"
            },
            {
              "lessThan": "45662dedb8f272ef7f16e69f13424c4bd0399240",
              "status": "affected",
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nilfs2/bmap.c",
            "fs/nilfs2/bmap.h",
            "fs/nilfs2/btree.c",
            "fs/nilfs2/direct.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.30"
            },
            {
              "lessThan": "2.6.30",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.270",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "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\nnilfs2: fix slab-out-of-bounds in nilfs_direct_propagate after truncation\n\nShuangpeng Bai reported that KASAN detected a slab-out-of-bounds error\nin nilfs_direct_propagate() during testing.\n\nAnalysis revealed that after truncating a file, a node block immediately\nbelow the B-tree root was not deleted.  Instead, it remained in the B-tree\nnode cache in a dirty state.  The log writer subsequently detected this\nblock and incorrectly invoked nilfs_direct_propagate() on it, which is\ndesigned to handle only data blocks in direct mapping.\n\nB-tree nodes in the cache are managed by virtual block numbers, and their\nlogical keys typically exceed the range expected by direct mapping.\nConsequently, processing such a node as a direct mapping entry triggers\na slab-out-of-bounds access.\n\nThe root cause is that when a B-tree mapping collapses into a direct\nmapping during truncation, an intermediate node block pointed to by the\nroot node is left behind as garbage instead of being explicitly deleted.\n\nThis resolves the issue by adding a nilfs_btree_discard() operation\nto delete the remaining intermediate node block during the conversion.\nA \u0027deform\u0027 flag is added to the bop_delete interface to explicitly signal\nthat the deletion is part of a mapping transformation.  This allows the\nB-tree mapping implementation to perform the necessary cleanup and\ndiscarding of the residual node structure that would be otherwise be left\norphaned after the transition."
    }
  ],
  "id": "CVE-2026-89723",
  "lastModified": "2026-09-14T13:19:21.417",
  "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": "2026-09-11T20:20:01.710",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/28362e8ce51377afdec1782e661e808328a10514"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/39005fd1ce654ffdecacddc406b9a038efe606e6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/448636c745a3f3b8582a0b8ce718c890a11c0fa9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/45662dedb8f272ef7f16e69f13424c4bd0399240"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4a1bb1f9f24a935c9b3f4fbf98012fa6d4ad826d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5d3783c451a546373662ee11ec17019273e68034"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b313edfbc0c2a60f7ce09b2e81ee71909ab8ddaf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bf49e6f6ddc12445a0330708b365de6458085980"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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