{"api_version":"1","generated_at":"2026-09-12T02:59:37+00:00","cve":"CVE-2026-89763","urls":{"html":"https://cve.report/CVE-2026-89763","api":"https://cve.report/api/cve/CVE-2026-89763.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89763","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89763"},"summary":{"title":"KEYS: trusted: Fix TPM teardown ordering","description":"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(&chip->dev)             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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:20:07","updated_at":"2026-09-11 20:20:07"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/5e2d672280d97d83de43031d93761b12dadd7b8a","name":"https://git.kernel.org/stable/c/5e2d672280d97d83de43031d93761b12dadd7b8a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2f7541afbc57fe9d26769a22c31d8ce8790c9a19","name":"https://git.kernel.org/stable/c/2f7541afbc57fe9d26769a22c31d8ce8790c9a19","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/753c978f2400f9783eb524842a975d3ac950d511","name":"https://git.kernel.org/stable/c/753c978f2400f9783eb524842a975d3ac950d511","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89763","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89763","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400 753c978f2400f9783eb524842a975d3ac950d511 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400 2f7541afbc57fe9d26769a22c31d8ce8790c9a19 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400 5e2d672280d97d83de43031d93761b12dadd7b8a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["security/keys/trusted-keys/trusted_tpm1.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"753c978f2400f9783eb524842a975d3ac950d511","status":"affected","version":"0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400","versionType":"git"},{"lessThan":"2f7541afbc57fe9d26769a22c31d8ce8790c9a19","status":"affected","version":"0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400","versionType":"git"},{"lessThan":"5e2d672280d97d83de43031d93761b12dadd7b8a","status":"affected","version":"0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["security/keys/trusted-keys/trusted_tpm1.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.1"},{"lessThan":"5.1","status":"unaffected","version":"0","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":"6.18.50","versionStartIncluding":"5.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"5.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"5.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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(&chip->dev)             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."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:47:04.352Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/753c978f2400f9783eb524842a975d3ac950d511"},{"url":"https://git.kernel.org/stable/c/2f7541afbc57fe9d26769a22c31d8ce8790c9a19"},{"url":"https://git.kernel.org/stable/c/5e2d672280d97d83de43031d93761b12dadd7b8a"}],"title":"KEYS: trusted: Fix TPM teardown ordering","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89763","datePublished":"2026-09-11T19:47:04.352Z","dateReserved":"2026-09-11T19:38:34.764Z","dateUpdated":"2026-09-11T19:47:04.352Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:20:07","lastModifiedDate":"2026-09-11 20:20:07","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89763","Ordinal":"1","Title":"KEYS: trusted: Fix TPM teardown ordering","CVE":"CVE-2026-89763","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89763","Ordinal":"1","NoteData":"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(&chip->dev)             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.","Type":"Description","Title":"KEYS: trusted: Fix TPM teardown ordering"}]}}}