SB20260912275 - Integer overflow in Linux kernel riscv kvm

Description

This security bulletin contains information about 1 vulnerability.

1) Integer overflow (CVE-ID: CVE-2026-89513)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to perform out-of-bounds reads and writes.

The vulnerability exists due to an integer overflow in the RISC-V KVM PMU event information handler when processing an SBI PMU EVENT_GET_INFO request with a guest-controlled event count. A local user can provide a num_events value that causes the shared-memory size calculation to truncate, resulting in an undersized array and out-of-bounds reads and writes.

Exploitation was demonstrated from a nested guest.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/735bc20c24187ca419c9d5e63860a54b91be34bd
• https://git.kernel.org/stable/c/82088f88c96b99c27a974d09b02c2b133262fadf