Vulnerability details

CVE-2025-39840

Linux Linux

audit: fix out-of-bounds read in audit_compare_dname_path()

CVSS 3.1
7.1High

Official description

In the Linux kernel, the following vulnerability has been resolved: audit: fix out-of-bounds read in audit_compare_dname_path() When a watch on dir=/ is combined with an fsnotify event for a single-character name directly under / (e.g., creating /a), an out-of-bounds read can occur in audit_compare_dname_path(). The helper parent_len() 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 then dereferences p[pathlen - 1] (i.e., p[-1]), causing an out-of-bounds read. Fix this by adding a pathlen > 0 check to the while loop condition to prevent the out-of-bounds access. [PM: subject tweak, sign-off email fixes]

CVSS scores

ScoreVersionSourceVector
7.1High 3.1 CISA ADP / Vulnrichment (CISA-ADP) CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
7.1High 3.1 CVEProject cvelistV5 (CNA) (Linux) CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products

VendorProductVersionsSource
Linux Linux 6.14 CVEProject cvelistV5 (CNA)
Linux Linux e92eebb0d6116f942ab25dfb1a41905aa59472a8 ≤ v < 9735a9dcc307427e7d6336c54171682f1bac9789 CVEProject cvelistV5 (CNA)
Linux Linux e92eebb0d6116f942ab25dfb1a41905aa59472a8 ≤ v < 4540f1d23e7f387880ce46d11b5cd3f27248bf8d CVEProject cvelistV5 (CNA)

References and advisories

2
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Details

Published
2025-09-19
Last updated
2026-08-05
State
Published
Assigner (CNA)
Linux

Exploit prediction (EPSS)

0.15%
Probability of exploitation in 30 days
4.5%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
No
Exploitation
None
Technical impact
Partial

Weaknesses (CWE)

  • CWE-125
    Out-of-bounds Read