Input Validation Flaw in Linux Kernel Affecting s390/zcrypt Component

CVE-2026-80546

What is CVE-2026-80546?

The Linux kernel's s390/zcrypt component contains vulnerabilities due to insufficient input validation in the xcrb_msg_to_type6cprb_msgx() function. An integer overflow can occur following 4-byte alignment, resulting in undersized buffer allocations. Additionally, the copying of the CPRBX structure from user space lacks checks for adequate buffer length, leading to potential uninitialized memory access. Also present is a risk of arithmetic overflow in sum calculations that could allow attackers to bypass essential size checks, resulting in buffer overflows. Remediation involves implementing size_t for length calculations, checking against U32_MAX after alignment, validating the minimum size of control blocks before copying, and incorporating overflow detection in sum calculations.

References