CVE-2026-68452: s390/zcrypt: Validate length for CCA AES cipher key requests

From: Greg Kroah-Hartman <[email protected]>

Description
===========

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

s390/zcrypt: Validate length for CCA AES cipher key requests

cca_cipher2protkey() derives the copy length for the CPRB parameter
block directly from the length field in the key token. Reject the
request early if the token length exceeds the available space in the
parameter block.

The Linux kernel CVE team has assigned CVE-2026-68452 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.4 with commit 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd and fixed in 6.6.151 with commit 406b317ea2b501f6f5eca1264293c9399a73a778
	Issue introduced in 5.4 with commit 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd and fixed in 6.12.103 with commit 4fc46deceda076d429ef3fab2ccf8d96629ebd23
	Issue introduced in 5.4 with commit 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd and fixed in 6.18.44 with commit ad93a1f1a45652478c0cf4eb029114e03af57f3b
	Issue introduced in 5.4 with commit 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd and fixed in 7.1.8 with commit 3859f630b674801a00bca39bc451f52288591f65
	Issue introduced in 5.4 with commit 4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd and fixed in 7.2-rc6 with commit 06afe425d5283b9764303de47f554da5a808ce8a

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-68452
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/s390/crypto/zcrypt_ccamisc.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/406b317ea2b501f6f5eca1264293c9399a73a778
	https://git.kernel.org/stable/c/4fc46deceda076d429ef3fab2ccf8d96629ebd23
	https://git.kernel.org/stable/c/ad93a1f1a45652478c0cf4eb029114e03af57f3b
	https://git.kernel.org/stable/c/3859f630b674801a00bca39bc451f52288591f65
	https://git.kernel.org/stable/c/06afe425d5283b9764303de47f554da5a808ce8a