CVE-2014-0155

What it actually does

Improper validation of the kvm_irq_delivery_to_apic return value in KVM I/O APIC code allows a guest to supply a crafted redirection table entry that crashes the host kernel.

Why it matters to the business

A malicious or compromised guest virtual machine can trigger a complete host denial of service, taking down all workloads on the affected system; the issue affects flux and flux-compat packages in Chainguard and Wolfi environments with fixes available since 2.2.3-r1.

How an attack unfolds

An attacker with guest OS access crafts a malicious entry in the I/O APIC redirection table to invoke the vulnerable ioapic_deliver path; the unhandled return value from kvm_irq_delivery_to_apic causes the host kernel to crash. Public exploit code has been available for years and the issue has been referenced in discussions of Linux kernel race condition and input validation flaws.

How to fix it

Upgrade to the fixed package versions: flux (Chainguard) 2.2.3-r1, flux (Wolfi) 2.2.3-r1, flux-compat (Chainguard) 2.2.3-r1, flux-compat (Wolfi) 2.2.3-r1. Rebuild and redeploy any container images that pull in the vulnerable packages.

How to confirm the fix worked

Confirm installed package versions meet or exceed the listed fixed releases; inspect kernel source or running KVM module for the presence of return-value validation in ioapic_service.

Typical attack path

1. Obtain or compromise a guest virtual machine on the target host
2. Write a crafted redirection table entry via guest I/O APIC interfaces
3. Trigger delivery that exercises the unvalidated return path
4. Cause host kernel panic and denial of service

How to detect it

Review host kernel logs for KVM I/O APIC related panics or oops messages; correlate with guest activity timestamps. Because the vulnerability is years old and has low exploitation probability, historical forensic searches are unlikely to yield recent indicators unless legacy unpatched systems remain.

What your security team should do

• Prioritize upgrade of all affected flux and flux-compat packages to 2.2.3-r1 or later across build and runtime environments
• Audit guest isolation boundaries and limit privileged access to virtual machines
• Monitor for host kernel panics in KVM environments even after patching