CVE-2025-39840

An out of bounds read exists in the linux kernel such that when a watch on dir=/ is combined with an fsnotify event for a single-character name directly under root an out-of-bounds read can occur in audit_compare_dname_path().

This vulnerability is rated as Moderate impact for Red Hat Enterprise Linux because exploitation requires local access alongside a non-default audit configuration, limiting the risk primarily to localized denial of service rather than arbitrary code execution. In standard Red Hat deployments, audit rules do not monitor the root filesystem directory by default, which is a mandatory prerequisite to expose this flaw. An attacker would need the ability to trigger filesystem events on single-character names directly under root while such a watch is active, potentially causing an out-of-bounds memory read that can lead to kernel instability or system crashes.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.