CVE-2021-47214

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.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/b5069d44e2fbc4a9093d005b3ef0949add3dd27e	Patch
https://git.kernel.org/stable/c/cc30042df6fcc82ea18acf0dace831503e60a0b7	Patch
https://git.kernel.org/stable/c/b5069d44e2fbc4a9093d005b3ef0949add3dd27e	Patch
https://git.kernel.org/stable/c/cc30042df6fcc82ea18acf0dace831503e60a0b7	Patch

Configurations

Configuration 1 (hide)

OR	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::::::

History

No history.

Information

Published : 2024-04-10 19:15

Updated : 2025-03-27 21:05

NVD link : CVE-2021-47214

Mitre link : CVE-2021-47214

CVE.ORG link : CVE-2021-47214

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-401

Missing Release of Memory after Effective Lifetime

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