CVE-2026-80708

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

s390/zcrypt: Fix missing mem scrub at clear key import in cca_clr2cipherkey()

The helper function _ip_cprb_helper() uses internal buffer memory for

building and processing CPRBs. After use this buffer was never

scrubbed which could lead to leaving for example clear key material in

memory which could be exposed via tricky reuse of this same memory.

Extend the _ip_cprb_helper() function with another parameter 'scrub'

used to steer scrubbing of this buffer. So now the caller has the

opportunity to decide if scrubbing is needed or not.

Extend the clear key to secure key token import process in function

cca_clr2cipherkey() to tell the helper function from above to scrub

the cprb buffer when the clear key value is part of the request data.

Add explicit scrubbing on return from function cca_clr2cipherkey() for

the random EXOR buffer and the cprb buffer.

Overall this cleans the internal used buffer in case of clear key

import to prevent sensitive data to get exposed.