In the Linux kernel, the following vulnerability has been resolved: s390/cio: Fix NULL pointer dereference in ccw_device_get_util_str() The channel… (CVE-2026-98476)

The vulnerability in the Linux kernel affects the s390 architecture's channel I/O subsystem. Specifically, the function ccw_device_get_util_str() can dereference a NULL pointer if the channel path registry entry associated with a CHPID is removed but the subchannel's PMCW still references that CHPID. The function chpid_to_chp() may return NULL in this scenario, and without a proper NULL check, this leads to a NULL pointer dereference. The issue has been resolved by adding the missing NULL check before dereferencing the pointer.

This vulnerability can cause a NULL pointer dereference, which typically results in a kernel crash or denial of service on affected systems running the s390 architecture Linux kernel. There is no information about exploitation in the wild or further impact such as privilege escalation.

A fix has been implemented in the Linux kernel to add the missing NULL check. Users should apply the official kernel updates that include this fix. Since this is a kernel-level issue, updating to the patched kernel version is the recommended remediation. Patch status is not explicitly provided; users should consult the Linux kernel vendor or distribution advisory for the exact fixed versions and update accordingly.