In the Linux kernel, the following vulnerability has been resolved:
x86/mm/ident_map: Use gbpages only where full GB page should be mapped.
When ident_pud_init() 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.
Metrics
Affected Vendors & Products
References
History
Fri, 25 Oct 2024 20:45:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Linux
Linux linux Kernel |
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Weaknesses | NVD-CWE-noinfo | |
CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
Vendors & Products |
Linux
Linux linux Kernel |
Wed, 23 Oct 2024 01:30:00 +0000
Type | Values Removed | Values Added |
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References |
| |
Metrics |
threat_severity
|
cvssV3_1
|
Tue, 22 Oct 2024 14:15:00 +0000
Type | Values Removed | Values Added |
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Metrics |
ssvc
|
Mon, 21 Oct 2024 19:00:00 +0000
Type | Values Removed | Values Added |
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Description | In the Linux kernel, the following vulnerability has been resolved: x86/mm/ident_map: Use gbpages only where full GB page should be mapped. When ident_pud_init() 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. | |
Title | x86/mm/ident_map: Use gbpages only where full GB page should be mapped. | |
References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-10-21T18:54:07.811Z
Updated: 2024-11-05T09:53:33.677Z
Reserved: 2024-10-21T12:17:06.063Z
Link: CVE-2024-50017
Vulnrichment
Updated: 2024-10-22T13:27:56.614Z
NVD
Status : Analyzed
Published: 2024-10-21T19:15:05.043
Modified: 2024-10-25T20:15:50.067
Link: CVE-2024-50017
Redhat