In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: fix memfd_pin_folios free_huge_pages leak
memfd_pin_folios followed by unpin_folios fails to restore free_huge_pages
if the pages were not already faulted in, because the folio refcount for
pages created by memfd_alloc_folio never goes to 0. memfd_pin_folios
needs another folio_put to undo the folio_try_get below:
memfd_alloc_folio()
alloc_hugetlb_folio_nodemask()
dequeue_hugetlb_folio_nodemask()
dequeue_hugetlb_folio_node_exact()
folio_ref_unfreeze(folio, 1); ; adds 1 refcount
folio_try_get() ; adds 1 refcount
hugetlb_add_to_page_cache() ; adds 512 refcount (on x86)
With the fix, after memfd_pin_folios + unpin_folios, the refcount for the
(unfaulted) page is 512, which is correct, as the refcount for a faulted
unpinned page is 513.
Metrics
Affected Vendors & Products
References
History
Thu, 07 Nov 2024 19:45:00 +0000
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First Time appeared |
Linux
Linux linux Kernel |
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Weaknesses | NVD-CWE-Other | |
CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
Vendors & Products |
Linux
Linux linux Kernel |
Tue, 22 Oct 2024 14:15:00 +0000
Type | Values Removed | Values Added |
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Metrics |
ssvc
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Tue, 22 Oct 2024 13:30:00 +0000
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References |
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Metrics |
threat_severity
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cvssV3_1
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Mon, 21 Oct 2024 18:15:00 +0000
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Description | In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix memfd_pin_folios free_huge_pages leak memfd_pin_folios followed by unpin_folios fails to restore free_huge_pages if the pages were not already faulted in, because the folio refcount for pages created by memfd_alloc_folio never goes to 0. memfd_pin_folios needs another folio_put to undo the folio_try_get below: memfd_alloc_folio() alloc_hugetlb_folio_nodemask() dequeue_hugetlb_folio_nodemask() dequeue_hugetlb_folio_node_exact() folio_ref_unfreeze(folio, 1); ; adds 1 refcount folio_try_get() ; adds 1 refcount hugetlb_add_to_page_cache() ; adds 512 refcount (on x86) With the fix, after memfd_pin_folios + unpin_folios, the refcount for the (unfaulted) page is 512, which is correct, as the refcount for a faulted unpinned page is 513. | |
Title | mm/hugetlb: fix memfd_pin_folios free_huge_pages leak | |
References |
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MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-10-21T18:02:15.755Z
Updated: 2024-12-19T09:30:17.408Z
Reserved: 2024-10-21T12:17:06.050Z
Link: CVE-2024-49964
Vulnrichment
Updated: 2024-10-22T13:34:46.906Z
NVD
Status : Analyzed
Published: 2024-10-21T18:15:17.510
Modified: 2024-11-07T19:20:04.357
Link: CVE-2024-49964
Redhat