CVE-2024-50193: x86/entry_32: Clear CPU buffers after register restore in NMI return
In the Linux kernel, the following vulnerability has been resolved:
x86/entry32: Clear CPU buffers after register restore in NMI return
CPU buffers are currently cleared after call to excnmi, 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 CLEARCPUBUFFERS after RESTOREALLNMI.
Other sources
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— Launchpad
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.22-1Fixed in 6.12.25-1 - Upgrade
Upgrade
debian/linux-6.1to a version that resolves this vulnerability.Fixed in 6.1.129-1~deb11u1 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 5.15.173.1-1 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.64.2-1 - Configuration
Update the x86/entry_32 NMI return code so that CLEAR_CPU_BUFFERS is executed after RESTORE_ALL_NMI (instead of after the call to exc_nmi and before register state is restored) to support correct RDFS mitigation when registers contain no sensitive data.
Linux kernel (x86/entry_32 NMI return path) Clear CPU buffers timing in NMI return = Move CLEAR_CPU_BUFFERS after RESTORE_ALL_NMI
Event History
Frequently Asked Questions
What is the severity of CVE-2024-50193?
CVE-2024-50193 is classified as a medium-severity vulnerability affecting the Linux kernel.
How do I fix CVE-2024-50193?
To address CVE-2024-50193, you should update your Linux kernel to a patched version as recommended by your distribution.
Which versions of the Linux kernel are affected by CVE-2024-50193?
CVE-2024-50193 affects Linux kernel versions from 5.10.228 up to but not including 6.12-rc1.
Does CVE-2024-50193 affect x86 architecture?
Yes, CVE-2024-50193 specifically impacts the x86 architecture in the Linux kernel.
Is there a known exploit for CVE-2024-50193?
As of now, there are no publicly disclosed exploits specifically targeting CVE-2024-50193.