CVE-2024-50017: x86/mm/ident_map: Use gbpages only where full GB page should be mapped.
In the Linux kernel, the following vulnerability has been resolved:
x86/mm/identmap: Use gbpages only where full GB page should be mapped.
When identpudinit() uses only GB pages to create identity maps, large ranges of addresses not actually requested can be included in the resulting table; a 4K request will map a full GB. This can include a lot of extra address space past that requested, including areas marked reserved by the BIOS. That allows processor speculation into reserved regions, that on UV systems can cause system halts.
Only use GB pages when map creation requests include the full GB page of space. Fall back to using smaller 2M pages when only portions of a GB page are included in the request.
No attempt is made to coalesce mapping requests. If a request requires a map entry at the 2M (pmd) level, subsequent mapping requests within the same 1G region will also be at the pmd level, even if adjacent or overlapping such requests could have been combined to map a full GB page. Existing usage starts with larger regions and then adds smaller regions, so this should not have any great consequence.
Other sources
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— Launchpad
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-50017?
CVE-2024-50017 has a medium severity rating due to its impact on memory mapping in the Linux kernel.
How do I fix CVE-2024-50017?
To fix CVE-2024-50017, upgrade your Linux kernel to version 6.10.14 or later, or 6.11.3 or later.
What systems are affected by CVE-2024-50017?
CVE-2024-50017 affects versions of the Linux kernel prior to 6.10.14 and from 6.11.0 to 6.11.3.
What is the impact of CVE-2024-50017?
The impact of CVE-2024-50017 includes potential vulnerabilities in memory management, which could lead to instability or unnecessary memory usage.
When was CVE-2024-50017 published?
CVE-2024-50017 was published in 2024 as part of ongoing security improvements in the Linux kernel.