Integer overflow in Linux kernel - CVE-2026-89513

Vulnerability details

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.

Affected software

How to mitigate CVE-2026-89513

External References

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

Related Security Bulletins

• Integer overflow in Linux kernel riscv kvm