CVE-2026-80545

/// Technical description

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

s390/zcrypt: Improve EP11 CPRB length and overflow checks

The xcrb_msg_to_type6_ep11cprb_msgx() function lacks proper input

validation, creating security vulnerabilities:

1. Missing minimum size validation: The ep11_cprb structure and

subsequent payload fields (pld_tag, pld_lenfmt) are copied from

userspace without verifying sufficient buffer length.

2. Arithmetic overflow in length calculations: CEIL4 alignment could

overflow, bypassing size checks and enabling buffer overflows.

3. The payload is asn1 encoded but the function just uses a simple c

struct overlay to access some fields of the payload.

Fix by using size_t for length calculations, adding U32_MAX boundary

checks after alignment, and validating minimum request size and

minimum reply size before copying from userspace. Do a very simple

asn1 parsing of the payload up to the function value field.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References