CVE-2026-68385 PUBLISHED

s390/checksum: Fix csum_partial() without vector facility

Assigner: Linux
Reserved: 30.07.2026 Published: 10.08.2026 Updated: 10.08.2026

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

s390/checksum: Fix csum_partial() without vector facility

Currently csum_partial() calls csum_copy() with copy=false and dst=NULL. On machines without the vector facility, csum_copy() falls back to cksm(dst, ...), causing the checksum to be calculated from address zero instead of the source buffer.

The VX implementation already checksums data loaded from src. Make the fallback do the same by passing src to cksm().

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from dcd3e1de9d17dc43dfed87a9fc814b9dec508043 to 5fc0a2a6eeb99cac991242bb48796c7749ce3261 (excl.)
  • affected from dcd3e1de9d17dc43dfed87a9fc814b9dec508043 to 1d9a2f01b3c4e5c88e06b2db4b5460c2ec884722 (excl.)
  • affected from dcd3e1de9d17dc43dfed87a9fc814b9dec508043 to 898bb2814f38399108bdd2113f38d97383a7036a (excl.)
  • affected from dcd3e1de9d17dc43dfed87a9fc814b9dec508043 to 4bb06b60d982355e22647b3d12d6619419f8c1fa (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.9 is affected
  • unaffected from 0 to 6.9 (excl.)
  • unaffected from 6.12.101 to 6.12.* (incl.)
  • unaffected from 6.18.42 to 6.18.* (incl.)
  • unaffected from 7.1.6 to 7.1.* (incl.)
  • unaffected from 7.2-rc4 to * (incl.)

References