PT-2025-3667 · Linux · Linux Kernel

Max Kellermann

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Published

2024-12-13

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Updated

2025-11-11

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CVE-2024-57942

CVSS v3.1

5.5

Medium

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description The issue arises in the Linux kernel's netfs subsystem, specifically when handling the copy to cache on write-begin operation for ceph filesystems. At the end of netfs unlock read folio(), where folios are marked for copying to the cache, the folio queue struct has its entry pointing to the folio cleared. This causes a problem for netfs pgpriv2 write to the cache(), which expects to traverse the folio queue list to find relevant folios, leading to a hang. The estimated number of potentially affected devices worldwide is not available. There is no information about real-world incidents where this issue was exploited.
Technical details about exploitation include:
  • The netfs unlock read folio() function
  • The folio queue struct
  • The netfs pgpriv2 write to the cache() function
  • The PG private 2 variable
Recommendations To resolve the issue, apply the fix by not clearing the folio queue entry if the deprecated copy-to-cache operation is to be performed. The clearance will be done instead as the folios are written to the cache. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Improper Locking

Weakness Enumeration

CWE-667

Related Identifiers

ALSA-2025:20095
BDU:2025-01771
CVE-2024-57942
RHSA-2025:20095

Affected Products

Linux Kernel