CVE-2023-53396 ubifs: Fix memory leak in do_rename
A memory leak in the Linux kernel's UBIFS filesystem allows attackers to exhaust system memory by renaming files in encrypted directories.
- 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-2023-53396?
CVE-2023-53396 is a medium-severity denial of service vulnerability in Linux kernel, published on 18 Sep 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:
ubifs: Fix memory leak in do_rename
If renaming a file in an encrypted directory, function fscrypt_setup_filename allocates memory for a file name. This name is never used, and before returning to the caller the memory for it is not freed.
When running kmemleak on it we see that it is registered as a leak. The report below is triggered by a simple program 'rename' that renames a file in an encrypted directory:
unreferenced object 0xffff888101502840 (size 32): comm "rename", pid 9404, jiffies 4302582475 (age 435.735s) backtrace: __kmem_cache_alloc_node __kmalloc fscrypt_setup_filename do_rename ubifs_rename vfs_rename do_renameat2
To fix this we can remove the call to fscrypt_setup_filename as it's not needed.
Weakness: CWE-401
Which versions are affected by CVE-2023-53396?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53396?
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-2023-53396 being exploited?
There is no known exploitation of CVE-2023-53396 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53396, DEBIAN-CVE-2023-53396, GHSA-427x-59vx-vjwq, UBUNTU-CVE-2023-53396.