# CVE-2022-49380: f2fs: fix to avoid f2fs_bug_on() in dec_valid_node_count()

> A local attacker can trigger a kernel panic in the F2FS file system by exploiting a bug in node count validation, causing a 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:** 26 Feb 2025
- **Updated:** 15 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-49380, GHSA-f8fm-xgpr-p643, UBUNTU-CVE-2022-49380

## What is CVE-2022-49380?

CVE-2022-49380 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Feb 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: fix to avoid f2fs_bug_on() in dec_valid_node_count()

As Yanming reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215897

I have encountered a bug in F2FS file system in kernel v5.17.

The kernel should enable CONFIG_KASAN=y and CONFIG_KASAN_INLINE=y. You can
reproduce the bug by running the following commands:

The kernel message is shown below:

kernel BUG at fs/f2fs/f2fs.h:2511!
Call Trace:
 f2fs_remove_inode_page+0x2a2/0x830
 f2fs_evict_inode+0x9b7/0x1510
 evict+0x282/0x4e0
 do_unlinkat+0x33a/0x540
 __x64_sys_unlinkat+0x8e/0xd0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The root cause is: .total_valid_block_count or .total_valid_node_count
could fuzzed to zero, then once dec_valid_node_count() was called, it
will cause BUG_ON(), this patch fixes to print warning info and set
SBI_NEED_FSCK into CP instead of panic.

## Which versions are affected by CVE-2022-49380?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49380?

Apply the vendor's patch.

## Is CVE-2022-49380 being exploited?

There is no known exploitation of CVE-2022-49380 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-2022-49380 and fix it if it is affected.

What it is: CVE-2022-49380 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Feb 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-2022-49380 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-2022-49380/ (Markdown: https://insights.sbomify.com/CVE-2022-49380/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49380
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49380
- OSV: https://osv.dev/vulnerability/CVE-2022-49380

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49380/
Summaries are generated and may contain mistakes; the official description above is the record.