A vulnerability in the Linux kernel s390/dasd driver allows for potential data corruption or unauthorized data access due to improper handling of partial request completions.

This is a logic error within the dasd_default_erp_postaction function, where the partial completion length (proc_bytes) is dropped during error recovery processing. An attacker with local access could potentially exploit this to cause the system to return zeroed data instead of actual disk contents, impacting data integrity.

The vulnerability carries a CVSS score of 7.0, reflecting its high impact on system integrity and confidentiality. Successful exploitation could result in the silent corruption of data or the disclosure of sensitive information by returning zeroed buffers during disk read operations. This poses a significant risk to enterprise environments relying on s390 architecture for data storage and processing.

Immediate Action: Update the Linux kernel to the identified patched versions (6.12.109, 6.18.50, or 7.2.4) or apply the relevant upstream fix commits to your distribution kernel.

Proactive Monitoring: Monitor system logs for unexpected ERP recovery failures or disk input/output errors that could indicate exploitation attempts against the dasd driver.

Compensating Controls: Restrict local access to the system to authorized users only, as the attack vector requires local privileges to interact with the vulnerable driver.

Public Exploit Available: Unknown.

Given the potential for silent data corruption, administrators should prioritize patching affected Linux kernels in environments utilizing s390/dasd hardware. Apply the upstream fixes provided by the maintainers immediately to ensure the integrity of storage operations and prevent potential unauthorized data exposure.