# CVE-2025-71107: f2fs: ensure node page reads complete before f2fs_put_super() finishes

> A race condition in the Linux kernel f2fs filesystem can cause a kernel crash during unmount, leading to 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:** 14 Jan 2026
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2025-71107, DEBIAN-CVE-2025-71107, GHSA-mcmw-vr9c-grh2, ROOT-OS-DEBIAN-13-CVE-2025-71107, ROOT-OS-UBUNTU-2204-CVE-2025-71107, ROOT-OS-UBUNTU-2404-CVE-2025-71107, UBUNTU-CVE-2025-71107

## What is CVE-2025-71107?

CVE-2025-71107 is a medium-severity vulnerability in Linux kernel, published on 14 Jan 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: ensure node page reads complete before f2fs_put_super() finishes

Xfstests generic/335, generic/336 sometimes crash with the following message:

F2FS-fs (dm-0): detect filesystem reference count leak during umount, type: 9, count: 1
------------[ cut here ]------------
kernel BUG at fs/f2fs/super.c:1939!
Oops: invalid opcode: 0000 [#1] SMP NOPTI
CPU: 1 UID: 0 PID: 609351 Comm: umount Tainted: G        W           6.17.0-rc5-xfstests-g9dd1835ecda5 #1 PREEMPT(none)
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:f2fs_put_super+0x3b3/0x3c0
Call Trace:
 <TASK>
 generic_shutdown_super+0x7e/0x190
 kill_block_super+0x1a/0x40
 kill_f2fs_super+0x9d/0x190
 deactivate_locked_super+0x30/0xb0
 cleanup_mnt+0xba/0x150
 task_work_run+0x5c/0xa0
 exit_to_user_mode_loop+0xb7/0xc0
 do_syscall_64+0x1ae/0x1c0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
 </TASK>
---[ end trace 0000000000000000 ]---

It appears that sometimes it is possible that f2fs_put_super() is called before
all node page reads are completed.
Adding a call to f2fs_wait_on_all_pages() for F2FS_RD_NODE fixes the problem.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-71107?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-71107?

Apply the vendor's patch.

## Is CVE-2025-71107 being exploited?

There is no known exploitation of CVE-2025-71107 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-2025-71107 and fix it if it is affected.

What it is: CVE-2025-71107 is a medium-severity vulnerability in Linux kernel, published on 14 Jan 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-2025-71107 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-2025-71107/ (Markdown: https://insights.sbomify.com/CVE-2025-71107/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71107
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71107
- OSV: https://osv.dev/vulnerability/CVE-2025-71107

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71107/
Summaries are generated and may contain mistakes; the official description above is the record.