CVE-2024-50193 x86/entry_32: Clear CPU buffers after register restore in NMI return
An attacker can exploit a flaw in the Linux kernel's NMI return path to potentially read sensitive data from CPU buffers via speculative execution side channels.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-50193?
CVE-2024-50193 is a high-severity vulnerability in Linux kernel, published on 8 Nov 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:
x86/entry_32: Clear CPU buffers after register restore in NMI return
CPU buffers are currently cleared after call to exc_nmi, but before register state is restored. This may be okay for MDS mitigation but not for RDFS. Because RDFS mitigation requires CPU buffers to be cleared when registers don't have any sensitive data.
Move CLEAR_CPU_BUFFERS after RESTORE_ALL_NMI.
Which versions are affected by CVE-2024-50193?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-50193?
Apply the vendor's patch.
Is CVE-2024-50193 being exploited?
There is no known exploitation of CVE-2024-50193 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-53555, AZL-53790, BELL-CVE-2024-50193, DEBIAN-CVE-2024-50193, GHSA-vw34-j5vp-r98r, UBUNTU-CVE-2024-50193.