SB2026062546 - Use-after-free in Linux kernel s390 crypto driver

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-53116)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in the AP bus driver_override handling in drivers/s390/crypto/ap_bus.c and drivers/s390/crypto/ap_queue.c when updating AP masks concurrently with driver_override sysfs operations. A local user can trigger concurrent driver_override changes and AP mask updates to cause a denial of service.

Exploitation requires access to local sysfs interfaces that modify AP mask or driver override settings.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/81d6f7c3a70b10ff757ee8b5f8114a190871cf1e
• https://git.kernel.org/stable/c/8f2eca0570438b94602da1297353eb7b10dcb6cb