Bug 2486445 (CVE-2026-46283)

Summary: CVE-2026-46283 kernel: tpm: Use kfree_sensitive() to free auth session in tpm_dev_release()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's Trusted Platform Module (TPM) driver. This vulnerability arises from the driver's failure to securely clear sensitive cryptographic material, such as session keys and passphrases, from memory when a TPM device is released. A local attacker could potentially exploit this by accessing the unscrubbed memory, leading to the disclosure of confidential cryptographic information. This could compromise the integrity and confidentiality of cryptographic operations.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-06-08 17:02:15 UTC 
In the Linux kernel, the following vulnerability has been resolved:

tpm: Use kfree_sensitive() to free auth session in tpm_dev_release()

tpm_dev_release() uses plain kfree() to free chip->auth, which contains
sensitive cryptographic material including HMAC session keys, nonces,
and passphrase data (struct tpm2_auth).

Every other code path that frees this structure uses kfree_sensitive()
to zero the memory before releasing it: both tpm2_end_auth_session()
and tpm_buf_check_hmac_response() do so. The tpm_dev_release() path
is the only one that does not, leaving key material in freed slab
memory until it is eventually overwritten.

Use kfree_sensitive() for consistency with the rest of the driver and
to ensure session keys are scrubbed during device teardown.
Comment 1 Keith Grant 2026-06-08 19:48:30 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026060842-CVE-2026-46283-5142@gregkh/T