Описание
Security update for xen
This update for xen fixes the following issues:
- CVE-2025-58150: Fixed buffer overrun with shadow paging and tracing (XSA-477) (bsc#1256745)
- CVE-2026-23553: Fixed incomplete IBPB for vCPU isolation (XSA-479) (bsc#1256747)
Список пакетов
openSUSE Leap 15.6
Ссылки
- Link for SUSE-SU-2026:0306-1
- E-Mail link for SUSE-SU-2026:0306-1
- SUSE Security Ratings
- SUSE Bug 1256745
- SUSE Bug 1256747
- SUSE CVE CVE-2025-58150 page
- SUSE CVE CVE-2026-23553 page
Описание
Shadow mode tracing code uses a set of per-CPU variables to avoid cumbersome parameter passing. Some of these variables are written to with guest controlled data, of guest controllable size. That size can be larger than the variable, and bounding of the writes was missing.
Затронутые продукты
Ссылки
- CVE-2025-58150
- SUSE Bug 1256745
Описание
In the context switch logic Xen attempts to skip an IBPB in the case of a vCPU returning to a CPU on which it was the previous vCPU to run. While safe for Xen's isolation between vCPUs, this prevents the guest kernel correctly isolating between tasks. Consider: 1) vCPU runs on CPU A, running task 1. 2) vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB. 3) On CPU B, guest kernel switches from task 1 to 2, issuing IBPB. 4) vCPU moves back to CPU A. Xen skips IBPB again. Now, task 2 is running on CPU A with task 1's training still in the BTB.
Затронутые продукты
Ссылки
- CVE-2026-23553
- SUSE Bug 1256747