CVE-2026-68385

A flaw was found in the Linux kernel's s390 architecture checksumming mechanism. On systems without a vector facility, the csum_partial() function incorrectly calculates checksums. This occurs because the csum_copy() function, when called with specific parameters, falls back to calculating the checksum from memory address zero instead of the intended source buffer. This can lead to incorrect checksums, potentially affecting data integrity within the kernel.

This issue affects s390 without vector facility. csum_partial() passes NULL dst to csum_copy fallback. s390 non-vector machines only.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.