CVE-2024-40938 landlock: Fix d_parent walk

What is CVE-2024-40938?

CVE-2024-40938 is a medium-severity vulnerability in Linux kernel, published on 12 Jul 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

landlock: Fix d_parent walk

The WARN_ON_ONCE() in collect_domain_accesses() can be triggered when trying to link a root mount point. This cannot work in practice because this directory is mounted, but the VFS check is done after the call to security_path_link().

Do not use source directory's d_parent when the source directory is the mount point.

[mic: Fix commit message]

Which versions are affected by CVE-2024-40938?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-40938?

Apply the vendor's patch.

Is CVE-2024-40938 being exploited?

There is no known exploitation of CVE-2024-40938 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2024-40938, DEBIAN-CVE-2024-40938, GHSA-p92j-gfh9-4hjj, UBUNTU-CVE-2024-40938.