# CVE-2025-38164: f2fs: zone: fix to avoid inconsistence in between SIT and SSA

> A local attacker can trigger a filesystem inconsistency in the Linux kernel's F2FS driver, causing the filesystem to stop and resulting in a denial of service.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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:** 3 Jul 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-38164, DEBIAN-CVE-2025-38164, GHSA-6mfc-3rhj-8xmq, ROOT-OS-UBUNTU-2404-CVE-2025-38164, UBUNTU-CVE-2025-38164

## What is CVE-2025-38164?

CVE-2025-38164 is a high-severity denial of service vulnerability in Linux kernel, published on 3 Jul 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:

f2fs: zone: fix to avoid inconsistence in between SIT and SSA

w/ below testcase, it will cause inconsistence in between SIT and SSA.

create_null_blk 512 2 1024 1024
mkfs.f2fs -m /dev/nullb0
mount /dev/nullb0 /mnt/f2fs/
touch /mnt/f2fs/file
f2fs_io pinfile set /mnt/f2fs/file
fallocate -l 4GiB /mnt/f2fs/file

F2FS-fs (nullb0): Inconsistent segment (0) type [1, 0] in SSA and SIT
CPU: 5 UID: 0 PID: 2398 Comm: fallocate Tainted: G           O       6.13.0-rc1 #84
Tainted: [O]=OOT_MODULE
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
Call Trace:
 <TASK>
 dump_stack_lvl+0xb3/0xd0
 dump_stack+0x14/0x20
 f2fs_handle_critical_error+0x18c/0x220 [f2fs]
 f2fs_stop_checkpoint+0x38/0x50 [f2fs]
 do_garbage_collect+0x674/0x6e0 [f2fs]
 f2fs_gc_range+0x12b/0x230 [f2fs]
 f2fs_allocate_pinning_section+0x5c/0x150 [f2fs]
 f2fs_expand_inode_data+0x1cc/0x3c0 [f2fs]
 f2fs_fallocate+0x3c3/0x410 [f2fs]
 vfs_fallocate+0x15f/0x4b0
 __x64_sys_fallocate+0x4a/0x80
 x64_sys_call+0x15e8/0x1b80
 do_syscall_64+0x68/0x130
 entry_SYSCALL_64_after_hwframe+0x67/0x6f
RIP: 0033:0x7f9dba5197ca
F2FS-fs (nullb0): Stopped filesystem due to reason: 4

The reason is f2fs_gc_range() may try to migrate block in curseg, however,
its SSA block is not uptodate due to the last summary block data is still
in cache of curseg.

In this patch, we add a condition in f2fs_gc_range() to check whether
section is opened or not, and skip block migration for opened section.

## Which versions are affected by CVE-2025-38164?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-38164?

Apply the vendor's patch.

## Is CVE-2025-38164 being exploited?

There is no known exploitation of CVE-2025-38164 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-2025-38164 and fix it if it is affected.

What it is: CVE-2025-38164 is a high-severity denial of service vulnerability in Linux kernel, published on 3 Jul 2025. 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-2025-38164 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-2025-38164/ (Markdown: https://insights.sbomify.com/CVE-2025-38164/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38164
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38164
- OSV: https://osv.dev/vulnerability/CVE-2025-38164

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38164/
Summaries are generated and may contain mistakes; the official description above is the record.