CVE-2026-97591
kernel: s390/crypto: Fix handling of EBUSY in PHMAC when req is pushed to crypto engine
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 25, 2026
Updated · September 29, 2026
Description
A flaw was found in the Linux kernel's s390 crypto subsystem. When processing Protected Key HMAC (PHMAC) operations, the driver improperly treats busy queue status codes from the cryptographic engine as failure conditions. A local user could exploit this flaw by submitting cryptographic requests during high load, prompting the driver to prematurely clear memory structures while requests are still in progress. This improper cleanup can lead to memory corruption or a system crash, resulting in a Denial of Service (DoS).
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-394 · Unexpected Status Code or Return Value