Linux Kernel EUVD-2026-38985

Vendor-released patch: upgrade to a fixed Linux kernel - 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1 or later - or apply your distribution's backport (Ubuntu users should install the kernels in USN-8566-1, USN-8567-1, and USN-8568-1 via a full apt upgrade and reboot). Non-Ubuntu users should track their distributor's advisory referencing the listed stable commits. Because the vulnerable code compiles and executes only on s390, systems on other architectures are not exposed and can deprioritize. Where immediate patching is not possible on IBM Z hosts, restrict local and root access to the machine and avoid handing out privileges that permit writing driver_override sysfs attributes or driving repeated driver (re)binding, since the trigger requires interacting with the channel-I/O device/driver binding path; note this only reduces, not eliminates, exposure to a local privileged actor.