PT-2025-38547 · Linux+2 · Linux Kernel+2

Published

2025-09-19

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Updated

2026-01-12

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CVE-2025-39840

CVSS v3.1

7.1

High

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Name of the Vulnerable Software and Affected Versions Linux Kernel (affected versions not specified)
Description An out-of-bounds read issue exists in the audit compare dname path() function within the Linux kernel. This occurs when a watch is set on the root directory (dir=/), combined with a file system notification event for a single-character name directly under the root directory (e.g., creating /a). The parent len() helper function returns 1 for "/". In audit compare dname path(), when parentlen equals the full path length (1), the code sets p = path + 1 and pathlen = 1 - 1 = 0. The subsequent loop dereferences p[pathlen - 1] (i.e., p[-1]), causing an out-of-bounds read.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Out of bounds Read

Weakness Enumeration

Related Identifiers

ALSA-2026:0445
ALSA-2026:0453
BDU:2025-14115
CVE-2025-39840
RHSA-2026:0445
RHSA-2026:0453

Affected Products

Astra Linux
Linux Kernel
Rocky Linux