SB2026091762 - Improper initialization in Linux kernel loongarch kvm

Description

This security bulletin contains information about 1 vulnerability.

1) Improper initialization (CVE-ID: CVE-2026-89908)

CWE-ID: CWE-665 - Improper Initialization

CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to compromise confidentiality, integrity, and availability.

The vulnerability exists due to improper preservation of memslot architecture flags in the LoongArch KVM memory-region handling code when processing a KVM_MR_FLAGS_ONLY memory-region update. A local user can perform a KVM_MR_FLAGS_ONLY update to compromise confidentiality, integrity, and availability.

The issue occurs when guest physical and host virtual address offsets within a PMD differ.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/27a9bfee3bbcb3cabb77797354f07e0e44e49831
• https://git.kernel.org/stable/c/4e4dbc341b1581dc512b85d98b768373b0398366
• https://git.kernel.org/stable/c/7c6df65b53846cd7a9a1c81c6ddb42fdc08603e8
• https://git.kernel.org/stable/c/bc7a6849b4395f45a602db91b0fb2fb2e9ed4bba