Bug 2554875 (CVE-2026-98476)

Summary: CVE-2026-98476 kernel: s390/cio: Fix NULL pointer dereference in ccw_device_get_util_str()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, 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 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).
 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 2026-10-18 15:24:39 UTC 
In the Linux kernel, the following vulnerability has been resolved:

s390/cio: Fix NULL pointer dereference in ccw_device_get_util_str()

The channel path registry entry associated with a CHPID may be removed
while the subchannel's PMCW still references that CHPID. In this case,
chpid_to_chp() can return NULL, leading to a NULL pointer dereference.

Add the missing NULL check before dereferencing the returned pointer.