# CVE-2026-31714: f2fs: fix to avoid memory leak in f2fs_rename()

> A memory leak in the Linux kernel's f2fs filesystem allows local attackers to exhaust system memory via rename operations, causing denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** Yes
- **Published:** 1 May 2026
- **Updated:** 14 Jun 2026
- **Also known as:** BELL-CVE-2026-31714, DEBIAN-CVE-2026-31714, GHSA-48wq-5h48-mwqq, ROOT-OS-UBUNTU-2404-CVE-2026-31714, UBUNTU-CVE-2026-31714

## What is CVE-2026-31714?

CVE-2026-31714 is a medium-severity memory corruption vulnerability in Linux kernel, published on 1 May 2026. 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:

f2fs: fix to avoid memory leak in f2fs_rename()

syzbot reported a f2fs bug as below:

BUG: memory leak
unreferenced object 0xffff888127f70830 (size 16):
  comm "syz.0.23", pid 6144, jiffies 4294943712
  hex dump (first 16 bytes):
    3c af 57 72 5b e6 8f ad 6e 8e fd 33 42 39 03 ff  <.Wr[...n..3B9..
  backtrace (crc 925f8a80):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4520 [inline]
    slab_alloc_node mm/slub.c:4844 [inline]
    __do_kmalloc_node mm/slub.c:5237 [inline]
    __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5250
    kmalloc_noprof include/linux/slab.h:954 [inline]
    fscrypt_setup_filename+0x15e/0x3b0 fs/crypto/fname.c:364
    f2fs_setup_filename+0x52/0xb0 fs/f2fs/dir.c:143
    f2fs_rename+0x159/0xca0 fs/f2fs/namei.c:961
    f2fs_rename2+0xd5/0xf20 fs/f2fs/namei.c:1308
    vfs_rename+0x7ff/0x1250 fs/namei.c:6026
    filename_renameat2+0x4f4/0x660 fs/namei.c:6144
    __do_sys_renameat2 fs/namei.c:6173 [inline]
    __se_sys_renameat2 fs/namei.c:6168 [inline]
    __x64_sys_renameat2+0x59/0x80 fs/namei.c:6168
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

The root cause is in commit 40b2d55e0452 ("f2fs: fix to create selinux
label during whiteout initialization"), we added a call to
f2fs_setup_filename() without a matching call to f2fs_free_filename(),
fix it.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-31714?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31714?

Apply the vendor's patch.

## Is CVE-2026-31714 being exploited?

There is no known exploitation of CVE-2026-31714 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31714 and fix it if it is affected.

What it is: CVE-2026-31714 is a medium-severity memory corruption vulnerability in Linux kernel, published on 1 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-31714 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-31714/ (Markdown: https://insights.sbomify.com/CVE-2026-31714/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31714
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31714
- OSV: https://osv.dev/vulnerability/CVE-2026-31714

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31714/
Summaries are generated and may contain mistakes; the official description above is the record.