CVE-2023-53662 ext4: fix memory leaks in ext4_fname_{setup_filename,prepare_lookup}

What is CVE-2023-53662?

CVE-2023-53662 is a medium-severity denial of service vulnerability in Linux kernel, published on 7 Oct 2025. 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:

ext4: fix memory leaks in ext4_fname_{setup_filename,prepare_lookup}

If the filename casefolding fails, we'll be leaking memory from the fscrypt_name struct, namely from the 'crypto_buf.name' member.

Make sure we free it in the error path on both ext4_fname_setup_filename() and ext4_fname_prepare_lookup() functions.

Weakness: CWE-401

Which versions are affected by CVE-2023-53662?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-53662?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2023-53662 being exploited?

There is no known exploitation of CVE-2023-53662 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 AZL-76419, BELL-CVE-2023-53662, DEBIAN-CVE-2023-53662, GHSA-6fcq-vj78-w895, ROOT-OS-UBUNTU-2204-CVE-2023-53662, UBUNTU-CVE-2023-53662.