Resource Leak Affecting kernel-debug package, versions *


Severity

Recommended
0.0
medium
0
10

Based on CentOS security rating.

Threat Intelligence

EPSS
0.04% (11th percentile)

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  • Snyk IDSNYK-CENTOS6-KERNELDEBUG-6606127
  • published12 Apr 2024
  • disclosed10 Apr 2024

Introduced: 10 Apr 2024

CVE-2021-47214  (opens in a new tab)
CWE-402  (opens in a new tab)

How to fix?

There is no fixed version for Centos:6 kernel-debug.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-debug package and not the kernel-debug package as distributed by Centos. See How to fix? for Centos:6 relevant fixed versions and status.

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 Scores

version 3.1