In the Linux kernel, the following vulnerability has been resolved: landlock: Require LANDLOCK_ACCESS_FS_MAKE_REG for whiteout creation Whiteout… (CVE-2026-89560)
A vulnerability in the Linux kernel's Landlock security module related to whiteout object creation in OverlayFS has been resolved. The fix requires the LANDLOCK_ACCESS_FS_MAKE_REG permission for creating whiteout objects, correcting previous permission checks that used LANDLOCK_ACCESS_FS_MAKE_CHAR. This change ensures proper permission enforcement for whiteout creation via mknod(2) and renameat2(2) system calls. The update also fixes a bug where renameat2(2) with RENAME_WHITEOUT could create directory entries even when all related Landlock permissions were denied.
AI Analysis
Technical Summary
The Linux kernel vulnerability CVE-2026-89560 involves improper permission checks in the Landlock security module for creating whiteout objects used by OverlayFS. Previously, whiteout creation via mknod(2) was guarded by LANDLOCK_ACCESS_FS_MAKE_CHAR, which was incorrect since whiteouts are not character devices. The patch changes this to require LANDLOCK_ACCESS_FS_MAKE_REG, aligning permissions with regular file creation. Additionally, a bug was fixed where renameat2(2) with RENAME_WHITEOUT could bypass Landlock restrictions and create directory entries without proper rights. This vulnerability has been resolved in the Linux kernel with the described permission enforcement improvements.
Potential Impact
The vulnerability allowed improper permission checks for creating whiteout objects in OverlayFS, potentially enabling unauthorized creation of these objects under Landlock confinement. This could lead to bypassing intended Landlock restrictions related to file system operations involving whiteouts. However, normal renames within layered OverlayFS mounts remain unaffected as they are controlled by the fuse-overlayfs daemon's Landlock domain.
Mitigation Recommendations
A fix is available in the Linux kernel that changes the required Landlock permission for whiteout creation to LANDLOCK_ACCESS_FS_MAKE_REG and corrects permission enforcement for renameat2(2) with RENAME_WHITEOUT. Users should apply the updated kernel version containing this patch to ensure proper Landlock permission checks. No additional mitigation is required beyond applying the official fix.
In the Linux kernel, the following vulnerability has been resolved: landlock: Require LANDLOCK_ACCESS_FS_MAKE_REG for whiteout creation Whiteout… (CVE-2026-89560)
Description
A vulnerability in the Linux kernel's Landlock security module related to whiteout object creation in OverlayFS has been resolved. The fix requires the LANDLOCK_ACCESS_FS_MAKE_REG permission for creating whiteout objects, correcting previous permission checks that used LANDLOCK_ACCESS_FS_MAKE_CHAR. This change ensures proper permission enforcement for whiteout creation via mknod(2) and renameat2(2) system calls. The update also fixes a bug where renameat2(2) with RENAME_WHITEOUT could create directory entries even when all related Landlock permissions were denied.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel vulnerability CVE-2026-89560 involves improper permission checks in the Landlock security module for creating whiteout objects used by OverlayFS. Previously, whiteout creation via mknod(2) was guarded by LANDLOCK_ACCESS_FS_MAKE_CHAR, which was incorrect since whiteouts are not character devices. The patch changes this to require LANDLOCK_ACCESS_FS_MAKE_REG, aligning permissions with regular file creation. Additionally, a bug was fixed where renameat2(2) with RENAME_WHITEOUT could bypass Landlock restrictions and create directory entries without proper rights. This vulnerability has been resolved in the Linux kernel with the described permission enforcement improvements.
Potential Impact
The vulnerability allowed improper permission checks for creating whiteout objects in OverlayFS, potentially enabling unauthorized creation of these objects under Landlock confinement. This could lead to bypassing intended Landlock restrictions related to file system operations involving whiteouts. However, normal renames within layered OverlayFS mounts remain unaffected as they are controlled by the fuse-overlayfs daemon's Landlock domain.
Mitigation Recommendations
A fix is available in the Linux kernel that changes the required Landlock permission for whiteout creation to LANDLOCK_ACCESS_FS_MAKE_REG and corrects permission enforcement for renameat2(2) with RENAME_WHITEOUT. Users should apply the updated kernel version containing this patch to ensure proper Landlock permission checks. No additional mitigation is required beyond applying the official fix.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-r9r3-96fh-8fhv
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-89560"]
Threat ID: 6aa4a00e55bf5e2cf5a86696
Added to database: 09/12/2026, 00:42:54 UTC
Last enriched: 09/12/2026, 01:05:09 UTC
Last updated: 09/12/2026, 01:05:09 UTC
Views: 2
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.