CVE-2026-68453 s390/zcrypt: Fix buffer over-read in cca_cipher2protkey

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix buffer over-read in ccacipher2protkey Add validation of both the actual key buffer size and token length fields in all the ccachecksectoken functions. Additionally check in ccagencipherkey for possible underflow...