CVE-2026-89458

About vulnerability

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.

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Debian 10 ELS , Debian 11 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU

Affected packages:

linux @ 4.19.0 (+5 more)

Live-patch status from KernelCare for each operating system.