CVE-2024-42230 powerpc/pseries: Fix scv instruction crash with kexec
A flaw in the Linux kernel's kexec sequence on pseries platforms allows a local attacker to crash the system by triggering an unexpected interrupt.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-42230?
CVE-2024-42230 is a medium-severity denial of service vulnerability in Linux kernel, published on 30 Jul 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries: Fix scv instruction crash with kexec
kexec on pseries disables AIL (reloc_on_exc), required for scv instruction support, before other CPUs have been shut down. This means they can execute scv instructions after AIL is disabled, which causes an interrupt at an unexpected entry location that crashes the kernel.
Change the kexec sequence to disable AIL after other CPUs have been brought down.
As a refresher, the real-mode scv interrupt vector is 0x17000, and the fixed-location head code probably couldn't easily deal with implementing such high addresses so it was just decided not to support that interrupt at all.
Which versions are affected by CVE-2024-42230?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-42230?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-42230 being exploited?
There is no known exploitation of CVE-2024-42230 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-47232, BELL-CVE-2024-42230, DEBIAN-CVE-2024-42230, GHSA-qf7q-7m3q-4gg2, ROOT-OS-DEBIAN-11-CVE-2024-42230, UBUNTU-CVE-2024-42230.