A vulnerability in the Linux kernel s390/pci subsystem allows leakage of uninitialized kernel data in SCLP error reports when user-space provides a short buffer. This causes an out-of-bounds read of up to around 4KB of kernel memory. The leak is limited to privileged entities that can already access the memory page containing the report, so it does not expose new data to unauthorized users. The issue results in malformed error reports that should be rejected.