CVE-2023-53473 ext4: improve error handling from ext4_dirhash()
An attacker can cause a denial of service in the Linux kernel by triggering an unhandled error in ext4_dirhash during encrypted or casefolded filename operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-53473?
CVE-2023-53473 is a high-severity vulnerability in Linux kernel, published on 1 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: improve error handling from ext4_dirhash()
The ext4_dirhash() will *almost* never fail, especially when the hash tree feature was first introduced. However, with the addition of support of encrypted, casefolded file names, that function can most certainly fail today.
So make sure the callers of ext4_dirhash() properly check for failures, and reflect the errors back up to their callers.
Which versions are affected by CVE-2023-53473?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53473?
Apply the vendor's patch.
Is CVE-2023-53473 being exploited?
There is no known exploitation of CVE-2023-53473 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53473, DEBIAN-CVE-2023-53473, GHSA-96w3-wxxm-9x2q, ROOT-OS-DEBIAN-11-CVE-2023-53473, UBUNTU-CVE-2023-53473.