CVE-2026-89723

Full vulnerability record from the local CVENow database.

Description

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.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-11 20:20:01.710000

Last modified

2026-10-19 09:18:12.910000

View original CVE JSON

{
  "id": "CVE-2026-89723",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:20:01.710",
  "lastModified": "2026-10-19T09:18:12.910",
  "vulnStatus": "Received",
  "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 'deform' 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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "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",
          "versions": [
            {
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "lessThan": "39005fd1ce654ffdecacddc406b9a038efe606e6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "lessThan": "bf49e6f6ddc12445a0330708b365de6458085980",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "lessThan": "4a1bb1f9f24a935c9b3f4fbf98012fa6d4ad826d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "lessThan": "b313edfbc0c2a60f7ce09b2e81ee71909ab8ddaf",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "lessThan": "5d3783c451a546373662ee11ec17019273e68034",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "lessThan": "448636c745a3f3b8582a0b8ce718c890a11c0fa9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "lessThan": "28362e8ce51377afdec1782e661e808328a10514",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "36a580eb489f54d81a0534974962e732a314b999",
              "lessThan": "45662dedb8f272ef7f16e69f13424c4bd0399240",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "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",
          "versions": [
            {
              "version": "2.6.30",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "2.6.30",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.270",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.221",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.188",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.109",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.50",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "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"
    },
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      "url": "https://git.kernel.org/stable/c/448636c745a3f3b8582a0b8ce718c890a11c0fa9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    }
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}