GHSA-53HQ-7C43-PVMJ
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33In the Linux kernel, the following vulnerability has been resolved:
tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt
tpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls crypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret() without installing a completion callback, discards both return values, and immediately frees the kpp_request via kpp_request_free(). When the resolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE, keembay-ocs), either operation returns -EINPROGRESS and the deferred completion worker dereferences the freed request.
The path fires automatically from the hwrng_fillfn kernel thread via tpm_get_random -> tpm2_get_random -> tpm2_start_auth_session -> tpm_buf_append_salt on every entropy poll, without any userland action.
Install crypto_req_done as the completion callback, wrap both KPP operations in crypto_wait_req(), and propagate errors to the caller. The wait is a no-op for synchronous backends.
{
"affected": [],
"aliases": [
"CVE-2026-72151"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:21:32Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt\n\ntpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls\ncrypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret()\nwithout installing a completion callback, discards both return values,\nand immediately frees the kpp_request via kpp_request_free(). When the\nresolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE,\nkeembay-ocs), either operation returns -EINPROGRESS and the deferred\ncompletion worker dereferences the freed request.\n\nThe path fires automatically from the hwrng_fillfn kernel thread via\ntpm_get_random -\u003e tpm2_get_random -\u003e tpm2_start_auth_session -\u003e\ntpm_buf_append_salt on every entropy poll, without any userland action.\n\nInstall crypto_req_done as the completion callback, wrap both KPP\noperations in crypto_wait_req(), and propagate errors to the caller.\nThe wait is a no-op for synchronous backends.",
"id": "GHSA-53hq-7c43-pvmj",
"modified": "2026-08-17T06:33:13Z",
"published": "2026-08-15T06:32:14Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72151"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/111e520efbe82b324bc42b1999b723c0619eea6d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/493333f167926c7adab8e7563e21ad71d8af84fa"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/73851a7c43dfa52d2ed9415889b33daf85da0ed9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/934d1cd40e2893bf7a041b54f6afd1c008d7a21c"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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Nomenclature
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