Vulnerability-Lookup

CVE-2026-89643 (GCVE-0-2026-89643)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:45 – Updated: 2026-09-13 06:32

Title

audit: avoid dropping live tree ref on fsnotify rule autoremove

Summary

In the Linux kernel, the following vulnerability has been resolved: audit: avoid dropping live tree ref on fsnotify rule autoremove audit_del_rule() is used for both netlink deletion templates and internal fsnotify autoremove. The former passes a parsed template which owns a temporary tree reference; the latter passes the installed entry itself. The unconditional audit_put_tree() at the end of audit_del_rule() assumes the template case. For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify autoremove event therefore drops the installed rule's live tree reference. Repeating this across rules sharing the same tree can free the tree while another rule still references it, and a later autoremove dereferences the freed pathname while comparing rules. Move the temporary-tree put to audit_rule_change(), the caller that owns deletion templates. Keep it in the AUDIT_DEL_RULE cleanup so both successful deletion and -ENOENT still release the parser-owned tree. [PM: dropped unnecessary comment for line length reasons]

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/cf37b61b5420fd460…
https://git.kernel.org/stable/c/636a99bab36ba2751…
https://git.kernel.org/stable/c/583cf579b32d99e3f…
https://git.kernel.org/stable/c/783f0f0974c156aca…

Impacted products

2 products

Vendor	Product	Version	CPE status
Linux	Linux	Affected: 34d99af52ad40bd498ba66970579a5bc1fb1a3bc , < cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28 (git) Affected: 34d99af52ad40bd498ba66970579a5bc1fb1a3bc , < 636a99bab36ba27515363d325866c0273ac83b3e (git) Affected: 34d99af52ad40bd498ba66970579a5bc1fb1a3bc , < 583cf579b32d99e3fe4e9c8ecc4d852e3708fbec (git) Affected: 34d99af52ad40bd498ba66970579a5bc1fb1a3bc , < 783f0f0974c156aca630f4ffff248671082a098d (git)	guessed
Linux	Linux	Affected: 4.3 Unaffected: 0 , < 4.3 (semver) Unaffected: 6.12.109 , ≤ 6.12.* (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/auditfilter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28",
              "status": "affected",
              "version": "34d99af52ad40bd498ba66970579a5bc1fb1a3bc",
              "versionType": "git"
            },
            {
              "lessThan": "636a99bab36ba27515363d325866c0273ac83b3e",
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              "versionType": "git"
            },
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              "versionType": "git"
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          "product": "Linux",
          "programFiles": [
            "kernel/auditfilter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.3"
            },
            {
              "lessThan": "4.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
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              "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"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "4.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "4.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "4.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "4.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naudit: avoid dropping live tree ref on fsnotify rule autoremove\n\naudit_del_rule() is used for both netlink deletion templates and internal\nfsnotify autoremove.  The former passes a parsed template which owns a\ntemporary tree reference; the latter passes the installed entry itself.\n\nThe unconditional audit_put_tree() at the end of audit_del_rule() assumes\nthe template case.  For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify\nautoremove event therefore drops the installed rule\u0027s live tree reference.\nRepeating this across rules sharing the same tree can free the tree while\nanother rule still references it, and a later autoremove dereferences the\nfreed pathname while comparing rules.\n\nMove the temporary-tree put to audit_rule_change(), the caller that owns\ndeletion templates.  Keep it in the AUDIT_DEL_RULE cleanup so both\nsuccessful deletion and -ENOENT still release the parser-owned tree.\n\n[PM: dropped unnecessary comment for line length reasons]"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - audit_autoremove_mark_rule() runs from fsnotify FS_MOVE_SELF/FS_DELETE_SELF/FS_UNMOUNT on the AUDIT_EXE parent directory; nfsd and ksmbd vfs_rename/vfs_rmdir of that directory reach the same path over the network, not only local renameat/rmdir.\nAC:L - Each EXE fsnotify autoremove deterministically extra-puts the live shared audit_tree; the attacker issues sequential directory renames/rmdirs they fully control and needs no race or memory layout beyond their influence.\nPR:N - Triggering requires only renaming or rmdir\u0027ing the parent directory of an audited executable on a local or NFS/SMB-exported path; a remote client needs no local account, CAP_AUDIT_CONTROL, or init-namespace root beyond export write access.\nUI:N - The attacker triggers autoremove with their own rename/rmdir (local or via nfsd/ksmbd); no other user must open files, mount a filesystem, or otherwise interact.\nS:U - The use-after-free corrupts host kernel heap (struct audit_tree) and stays within the same kernel security authority; it is not a VM escape, IOMMU bypass, or other documented cross-boundary impact.\nC:H - Use-after-free of the shared audit_tree lets a later audit_compare_rule() strcmp the freed pathname and remaining rules dereference attacker-reclaimed tree objects, enabling arbitrary kernel reads.\nI:H - The dangling tree is then used in audit_remove_tree_rule() list_del/list_move and prune_one() after extra puts free it, enabling heap spraying, list corruption, arbitrary writes, and control-flow hijack.\nA:H - Dereferencing the freed audit_tree pathname or underflowing its refcount during prune oopses/panics the kernel; the UAF can be triggered repeatedly for denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-13T06:32:22.869Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28"
        },
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          "url": "https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e"
        },
        {
          "url": "https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec"
        },
        {
          "url": "https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d"
        }
      ],
      "title": "audit: avoid dropping live tree ref on fsnotify rule autoremove",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89643",
    "datePublished": "2026-09-11T19:45:35.523Z",
    "dateReserved": "2026-09-11T19:38:34.741Z",
    "dateUpdated": "2026-09-13T06:32:22.869Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-89643",
      "date": "2026-09-13",
      "epss": "0.00626",
      "percentile": "0.48083"
    },
    "microsoft_vex": {
      "current_release_date": "2026-09-13T01:12:23.000Z",
      "cve": "CVE-2026-89643",
      "id": "msrc_CVE-2026-89643",
      "initial_release_date": "2026-09-13T01:12:23.000Z",
      "product_status:under_investigation": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "audit: avoid dropping live tree ref on fsnotify rule autoremove",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89643.json",
      "version": "1"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-89643\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-11T20:19:50.090\",\"lastModified\":\"2026-09-13T07:17:29.590\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\naudit: avoid dropping live tree ref on fsnotify rule autoremove\\n\\naudit_del_rule() is used for both netlink deletion templates and internal\\nfsnotify autoremove.  The former passes a parsed template which owns a\\ntemporary tree reference; the latter passes the installed entry itself.\\n\\nThe unconditional audit_put_tree() at the end of audit_del_rule() assumes\\nthe template case.  For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify\\nautoremove event therefore drops the installed rule\u0027s live tree reference.\\nRepeating this across rules sharing the same tree can free the tree while\\nanother rule still references it, and a later autoremove dereferences the\\nfreed pathname while comparing rules.\\n\\nMove the temporary-tree put to audit_rule_change(), the caller that owns\\ndeletion templates.  Keep it in the AUDIT_DEL_RULE cleanup so both\\nsuccessful deletion and -ENOENT still release the parser-owned tree.\\n\\n[PM: dropped unnecessary comment for line length reasons]\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"kernel/auditfilter.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"34d99af52ad40bd498ba66970579a5bc1fb1a3bc\",\"lessThan\":\"cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"34d99af52ad40bd498ba66970579a5bc1fb1a3bc\",\"lessThan\":\"636a99bab36ba27515363d325866c0273ac83b3e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"34d99af52ad40bd498ba66970579a5bc1fb1a3bc\",\"lessThan\":\"583cf579b32d99e3fe4e9c8ecc4d852e3708fbec\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"34d99af52ad40bd498ba66970579a5bc1fb1a3bc\",\"lessThan\":\"783f0f0974c156aca630f4ffff248671082a098d\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"kernel/auditfilter.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"4.3\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"4.3\",\"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-rc1\",\"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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":9.8,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-13T06:59:48+00:00",
      "cve": "CVE-2026-89643",
      "id": "CVE-2026-89643",
      "initial_release_date": "2026-09-11T19:45:35.523000+00:00",
      "product_status:known_affected": "2",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Linux Kernel: Audit subsystem memory corruption via fsnotify rule autoremove",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89643.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-09-12T16:24:25Z",
      "cve": "CVE-2026-89643",
      "id": "CVE-2026-89643",
      "initial_release_date": "2026-09-12T16:24:25Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-89643",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-89643.json",
      "version": "2"
    }
  }
}

FKIE_CVE-2026-89643

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-13 07:17

Severity

9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/auditfilter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28",
              "status": "affected",
              "version": "34d99af52ad40bd498ba66970579a5bc1fb1a3bc",
              "versionType": "git"
            },
            {
              "lessThan": "636a99bab36ba27515363d325866c0273ac83b3e",
              "status": "affected",
              "version": "34d99af52ad40bd498ba66970579a5bc1fb1a3bc",
              "versionType": "git"
            },
            {
              "lessThan": "583cf579b32d99e3fe4e9c8ecc4d852e3708fbec",
              "status": "affected",
              "version": "34d99af52ad40bd498ba66970579a5bc1fb1a3bc",
              "versionType": "git"
            },
            {
              "lessThan": "783f0f0974c156aca630f4ffff248671082a098d",
              "status": "affected",
              "version": "34d99af52ad40bd498ba66970579a5bc1fb1a3bc",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/auditfilter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.3"
            },
            {
              "lessThan": "4.3",
              "status": "unaffected",
              "version": "0",
              "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\naudit: avoid dropping live tree ref on fsnotify rule autoremove\n\naudit_del_rule() is used for both netlink deletion templates and internal\nfsnotify autoremove.  The former passes a parsed template which owns a\ntemporary tree reference; the latter passes the installed entry itself.\n\nThe unconditional audit_put_tree() at the end of audit_del_rule() assumes\nthe template case.  For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify\nautoremove event therefore drops the installed rule\u0027s live tree reference.\nRepeating this across rules sharing the same tree can free the tree while\nanother rule still references it, and a later autoremove dereferences the\nfreed pathname while comparing rules.\n\nMove the temporary-tree put to audit_rule_change(), the caller that owns\ndeletion templates.  Keep it in the AUDIT_DEL_RULE cleanup so both\nsuccessful deletion and -ENOENT still release the parser-owned tree.\n\n[PM: dropped unnecessary comment for line length reasons]"
    }
  ],
  "id": "CVE-2026-89643",
  "lastModified": "2026-09-13T07:17:29.590",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T20:19:50.090",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec"
    },
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      "url": "https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e"
    },
    {
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      "url": "https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-QH9H-FG7C-VGXW

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-13 09:32

Details

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

audit: avoid dropping live tree ref on fsnotify rule autoremove

audit_del_rule() is used for both netlink deletion templates and internal fsnotify autoremove. The former passes a parsed template which owns a temporary tree reference; the latter passes the installed entry itself.

The unconditional audit_put_tree() at the end of audit_del_rule() assumes the template case. For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify autoremove event therefore drops the installed rule's live tree reference. Repeating this across rules sharing the same tree can free the tree while another rule still references it, and a later autoremove dereferences the freed pathname while comparing rules.

Move the temporary-tree put to audit_rule_change(), the caller that owns deletion templates. Keep it in the AUDIT_DEL_RULE cleanup so both successful deletion and -ENOENT still release the parser-owned tree.

[PM: dropped unnecessary comment for line length reasons]

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-89643"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:50Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\naudit: avoid dropping live tree ref on fsnotify rule autoremove\n\naudit_del_rule() is used for both netlink deletion templates and internal\nfsnotify autoremove.  The former passes a parsed template which owns a\ntemporary tree reference; the latter passes the installed entry itself.\n\nThe unconditional audit_put_tree() at the end of audit_del_rule() assumes\nthe template case.  For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify\nautoremove event therefore drops the installed rule\u0027s live tree reference.\nRepeating this across rules sharing the same tree can free the tree while\nanother rule still references it, and a later autoremove dereferences the\nfreed pathname while comparing rules.\n\nMove the temporary-tree put to audit_rule_change(), the caller that owns\ndeletion templates.  Keep it in the AUDIT_DEL_RULE cleanup so both\nsuccessful deletion and -ENOENT still release the parser-owned tree.\n\n[PM: dropped unnecessary comment for line length reasons]",
  "id": "GHSA-qh9h-fg7c-vgxw",
  "modified": "2026-09-13T09:32:26Z",
  "published": "2026-09-11T21:31:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89643"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

MSRC_CVE-2026-89643

Vulnerability from csaf_microsoft - Published: 2026-09-13 01:12 - Updated: 2026-09-13 01:12

Summary

audit: avoid dropping live tree ref on fsnotify rule autoremove

Notes

Additional Resources: To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

Disclaimer: The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

CVE-2026-89643

Affected products

Under investigation 1 product

Product	Identifier	Version	Remediation
Unresolved product id: 17084-1		—

References

4 references

URL	Category
https://msrc.microsoft.com/csaf/vex/2026/msrc_cve…	self
https://support.microsoft.com/lifecycle	external
https://www.first.org/cvss	external
https://msrc.microsoft.com/csaf/vex/2026/msrc_cve…	self

JSON

To clipboard

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-89643 audit: avoid dropping live tree ref on fsnotify rule autoremove - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89643.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "audit: avoid dropping live tree ref on fsnotify rule autoremove",
    "tracking": {
      "current_release_date": "2026-09-13T01:12:23.000Z",
      "generator": {
        "date": "2026-09-13T07:02:34.795Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-89643",
      "initial_release_date": "2026-09-13T01:12:23.000Z",
      "revision_history": [
        {
          "date": "2026-09-13T01:12:23.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "category": "product_name",
            "name": "azl3 kernel 0:6.6.150.1-1.azl3",
            "product": {
              "name": "azl3 kernel 0:6.6.150.1-1.azl3",
              "product_id": "1"
            }
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 kernel 0:6.6.150.1-1.azl3 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-89643",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "under_investigation": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-89643 audit: avoid dropping live tree ref on fsnotify rule autoremove - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89643.json"
        }
      ],
      "title": "audit: avoid dropping live tree ref on fsnotify rule autoremove"
    }
  ]
}

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

CVE-2026-89643 (GCVE-0-2026-89643)

FKIE_CVE-2026-89643

GHSA-QH9H-FG7C-VGXW

MSRC_CVE-2026-89643

Tags

Sightings

Nomenclature