{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400"
            },
            {
              "fixed": "753c978f2400f9783eb524842a975d3ac950d511"
            },
            {
              "fixed": "2f7541afbc57fe9d26769a22c31d8ce8790c9a19"
            },
            {
              "fixed": "5e2d672280d97d83de43031d93761b12dadd7b8a"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.1.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89763.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKEYS: trusted: Fix TPM teardown ordering\n\ntrusted_tpm_exit() drops the TPM chip reference and frees the digest\narray before unregistering the trusted key type. key_type_lookup()\nholds key_types_sem for reading until the key operation finishes, while\nunregister_key_type() takes it for writing. It therefore provides the\nsynchronization point that must precede backend teardown.\n\nThe current order permits this interleaving:\n\n  CPU 0                              CPU 1\n  trusted_tpm_exit()                 key_type_lookup(\"trusted\")\n    put_device(\u0026chip-\u003edev)             trusted_tpm_seal()\n    kfree(digests)                       pcrlock()\n    unregister_key_type()                  tpm_pcr_extend(..., digests)\n\nCPU 1 can consequently dereference the freed digest array. The chip can\nalso be released before callbacks stop using it.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in tpm_pcr_extend+0x1f0/0x200\n  Read of size 2 at addr ffff88810872d000 by task poc/89\n  Call Trace:\n    tpm_pcr_extend+0x1f0/0x200\n    pcrlock+0x42/0x70 [trusted]\n    trusted_tpm_seal+0x1b6/0x570 [trusted]\n    trusted_instantiate+0x293/0x340 [trusted]\n    __key_instantiate_and_link+0xb2/0x2b0\n    __key_create_or_update+0x61e/0xb50\n    __do_sys_add_key+0x1b8/0x310\n  Allocated by task 88:\n    __kmalloc_noprof+0x1a7/0x490\n    do_one_initcall+0xa1/0x390\n    do_init_module+0x2df/0x840\n  Freed by task 90:\n    kfree+0x131/0x3c0\n    trusted_tpm_exit+0x59/0xa0 [trusted]\n    __do_sys_delete_module+0x346/0x510\n\nMove unregister_key_type() before releasing either resource. This stops\nnew lookups and waits for in-flight key operations to finish before the\nbackend state is destroyed.",
  "id": "CVE-2026-89763",
  "modified": "2026-09-15T03:30:53.586061613Z",
  "published": "2026-09-11T19:47:04.352Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2f7541afbc57fe9d26769a22c31d8ce8790c9a19"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5e2d672280d97d83de43031d93761b12dadd7b8a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/753c978f2400f9783eb524842a975d3ac950d511"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89763.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89763"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "KEYS: trusted: Fix TPM teardown ordering"
}