In the Linux kernel, the following vulnerability has been resolved:

hugetlb, userfaultfd: fix reservation restore on userfaultfd error

Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we
bail out using "goto out_release_unlock;" in the cases where idx >=
size, or !huge_pte_none(), the code will detect that new_pagecache_page
== false, and so call restore_reserve_on_error(). In this case I see
restore_reserve_on_error() delete the reservation, and the following
call to remove_inode_hugepages() will increment h->resv_hugepages
causing a 100% reproducible leak.

We should treat the is_continue case similar to adding a page into the
pagecache and set new_pagecache_page to true, to indicate that there is
no reservation to restore on the error path, and we need not call
restore_reserve_on_error(). Rename new_pagecache_page to
page_in_pagecache to make that clear.

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History

Thu, 27 Mar 2025 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-401
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13.13:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Mon, 04 Nov 2024 12:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T12:41:16.227Z

Reserved: 2024-04-10T18:59:19.528Z

Link: CVE-2021-47214

cve-icon Vulnrichment

Updated: 2024-08-04T05:32:07.447Z

cve-icon NVD

Status : Analyzed

Published: 2024-04-10T19:15:48.680

Modified: 2025-03-27T21:05:27.253

Link: CVE-2021-47214

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-04-10T00:00:00Z

Links: CVE-2021-47214 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses