CVE-2021-20321
kernel: In Overlayfs missing a check for a negative dentry before calling vfs_rename()
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · October 11, 2021
Updated · November 1, 2026
Description
A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.
CVSS score applicability
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
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.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization