Description (CNA)
In 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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 1085b8276bb4239daa7008f0dcd5c973e4bd690f before 111e520efbe82b324bc42b1999b723c0619eea6d; affected 1085b8276bb4239daa7008f0dcd5c973e4bd690f before 934d1cd40e2893bf7a041b54f6afd1c008d7a21c; affected 1085b8276bb4239daa7008f0dcd5c973e4bd690f before 493333f167926c7adab8e7563e21ad71d8af84fa; affected 1085b8276bb4239daa7008f0dcd5c973e4bd690f before 73851a7c43dfa52d2ed9415889b33daf85da0ed9 |
| Linux / Linux | affected 6.10; unaffected 0 before 6.10; unaffected 6.12.97 through 6.12.*; unaffected 6.18.40 through 6.18.*; unaffected 7.1.5 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.