CVE-2026-89458

In the Linux kernel, the following vulnerability has been resolved:

s390/dasd: Do not complete a failed ESE read as successful

dasd_int_handler() completes an NRF read of an unallocated ESE track by

calling ese_read() and unconditionally marking the request

DASD_CQR_SUCCESS. dasd_eckd_ese_read() can return an error before it has

zeroed the destination buffer: a failed sense-data parse or a current

track outside the requested range both return early, leaving the

destination pages untouched. The request is still completed successfully,

so the block layer is handed stale / uninitialized memory instead of

zeros.

Check the ese_read() return value and fail the request through the normal

error path instead of forcing DASD_CQR_SUCCESS.