CVE-2026-98476
kernel: s390/cio: Fix NULL pointer dereference in ccw_device_get_util_str()
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · October 18, 2026
Updated · October 30, 2026
Description
A flaw was found in the Linux kernel's s390 channel I/O (CIO) subsystem. When querying device utility strings, the kernel fails to verify that an associated channel path remains valid after its removal from the registry. A local user could exploit this condition during hardware reconfiguration, resulting in a NULL pointer dereference that causes a system crash and Denial of Service (DoS).
Statement
This vulnerability is rated as having a Moderate impact because it is restricted to systems running on the IBM Z (s390x) architecture and only results in a local denial of service. Exploitation requires specific timing during dynamic channel path reconfiguration and concurrent device queries, presenting high complexity and preventing code execution or unauthorized data exposure. Systems operating on non-s390x hardware architectures are not vulnerable.
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 · 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-476 · NULL Pointer Dereference