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

s390/zcrypt: Improve CCA CPRB length and overflow checks

The xcrb_msg_to_type6cprb_msgx() function lacks proper input
validation, creating security vulnerabilities:
1. Integer overflow after CEIL4 alignment: Signed int variables could
overflow during 4-byte boundary alignment, causing undersized
buffer allocations or incorrect bounds checking.
2. Missing minimum size validation: The CPRBX structure is copied from
userspace without verifying sufficient buffer length. Undersized
buffers cause uninitialized memory access when reading structure
fields like cprbx.cprb_len and cprbx.domain.
3. Arithmetic overflow in sum calculations: Adding control block and
data block sizes could overflow, bypassing size checks and enabling
buffer overflows.

Fix by using size_t for length calculations, adding U32_MAX boundary
checks after alignment, validating minimum control block size before
copying from userspace, and detecting sum calculation overflows.
Published: 2026-08-26
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Wed, 26 Aug 2026 14:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Improve CCA CPRB length and overflow checks The xcrb_msg_to_type6cprb_msgx() function lacks proper input validation, creating security vulnerabilities: 1. Integer overflow after CEIL4 alignment: Signed int variables could overflow during 4-byte boundary alignment, causing undersized buffer allocations or incorrect bounds checking. 2. Missing minimum size validation: The CPRBX structure is copied from userspace without verifying sufficient buffer length. Undersized buffers cause uninitialized memory access when reading structure fields like cprbx.cprb_len and cprbx.domain. 3. Arithmetic overflow in sum calculations: Adding control block and data block sizes could overflow, bypassing size checks and enabling buffer overflows. Fix by using size_t for length calculations, adding U32_MAX boundary checks after alignment, validating minimum control block size before copying from userspace, and detecting sum calculation overflows.
Title s390/zcrypt: Improve CCA CPRB length and overflow checks
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-26T14:37:17.550Z

Reserved: 2026-08-26T14:34:25.765Z

Link: CVE-2026-80546

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-26T15:17:08.977

Modified: 2026-08-26T15:17:08.977

Link: CVE-2026-80546

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.