CVE-2026-68451: s390/zcrypt: Validate length for CCA ECC private 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 ECC private key requests

cca_ecc2protkey() 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-2026-68451 to this issue.


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

	Issue introduced in 5.10 with commit fa6999e326fe7851ecbd572b8cb9be8e930ebf41 and fixed in 6.6.151 with commit dd25bd9b0f36849808bd7625dcc59dd4c1aeef3e
	Issue introduced in 5.10 with commit fa6999e326fe7851ecbd572b8cb9be8e930ebf41 and fixed in 6.12.103 with commit ecc3b8691c1935f9f3e4eb964ab11e40fdec17f5
	Issue introduced in 5.10 with commit fa6999e326fe7851ecbd572b8cb9be8e930ebf41 and fixed in 6.18.44 with commit 013a4484f061a2b41f052e25c0015203287e63f1
	Issue introduced in 5.10 with commit fa6999e326fe7851ecbd572b8cb9be8e930ebf41 and fixed in 7.1.8 with commit 8fa3e9435a13c335efb63fb4f4e77531a0031159
	Issue introduced in 5.10 with commit fa6999e326fe7851ecbd572b8cb9be8e930ebf41 and fixed in 7.2-rc6 with commit a9ae0f6dd45c3ccc1d69363f7aea8af179122730

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-2026-68451
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/dd25bd9b0f36849808bd7625dcc59dd4c1aeef3e
	https://git.kernel.org/stable/c/ecc3b8691c1935f9f3e4eb964ab11e40fdec17f5
	https://git.kernel.org/stable/c/013a4484f061a2b41f052e25c0015203287e63f1
	https://git.kernel.org/stable/c/8fa3e9435a13c335efb63fb4f4e77531a0031159
	https://git.kernel.org/stable/c/a9ae0f6dd45c3ccc1d69363f7aea8af179122730