Vulnerability Database

314,343

Total vulnerabilities in the database

CVE-2025-39840

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]

  • Published: Sep 19, 2025
  • Updated: Dec 15, 2025
  • CVE: CVE-2025-39840
  • Severity: High
  • Exploit:

CVSS v3:

  • Severity: High
  • Score: 7.1
  • AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

CWEs: