In the Linux kernel, the following vulnerability has been resolved: s390/cmf: Fix virtual vs physical address confusion The measurement block… (CVE-2026-98475)

The Linux kernel s390/cmf subsystem had a vulnerability due to confusion between virtual and physical addresses in handling the measurement block address, which is an absolute address. The schib_config and schib fields were not properly defined as dma64_t, preventing automatic detection of incorrect address assignments. Additionally, the virt_to_dma64() translation was missing. Without this fix, firmware would use incorrect addresses when storing extended format channel measurement data on kernels compiled with CONFIG_RANDOMIZE_IDENTITY_BASE=y. This vulnerability has been resolved by correcting the field definitions and adding the missing translation.

Firmware could use incorrect addresses for storing extended format channel measurement data on affected Linux kernels, potentially leading to incorrect measurement data handling or related malfunctions on s390 architecture systems built with CONFIG_RANDOMIZE_IDENTITY_BASE=y. No known exploits in the wild have been reported.

A fix has been applied in the Linux kernel source to correct the address confusion issue. Users should update to the fixed kernel version once available. Since this is a kernel-level fix, applying the official kernel update from the vendor or distribution is the recommended remediation. Patch status is not explicitly confirmed in the provided data; users should check the vendor advisory or kernel release notes for the exact fixed version and update accordingly.