# CVE-2024-56692: f2fs: fix to do sanity check on node blkaddr in truncate_node()

> A local attacker can cause a kernel panic and system crash by mounting a specially crafted f2fs filesystem image with corrupted node block addresses.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 28 Dec 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-55739, AZL-55804, BELL-CVE-2024-56692, DEBIAN-CVE-2024-56692, GHSA-hc7h-3x34-frvv, ROOT-OS-DEBIAN-11-CVE-2024-56692, ROOT-OS-DEBIAN-12-CVE-2024-56692, ROOT-OS-UBUNTU-2204-CVE-2024-56692, UBUNTU-CVE-2024-56692

## What is CVE-2024-56692?

CVE-2024-56692 is a high-severity denial of service vulnerability in Linux kernel, published on 28 Dec 2024. 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 do sanity check on node blkaddr in truncate_node()

syzbot reports a f2fs bug as below:

------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:2534!
RIP: 0010:f2fs_invalidate_blocks+0x35f/0x370 fs/f2fs/segment.c:2534
Call Trace:
 truncate_node+0x1ae/0x8c0 fs/f2fs/node.c:909
 f2fs_remove_inode_page+0x5c2/0x870 fs/f2fs/node.c:1288
 f2fs_evict_inode+0x879/0x15c0 fs/f2fs/inode.c:856
 evict+0x4e8/0x9b0 fs/inode.c:723
 f2fs_handle_failed_inode+0x271/0x2e0 fs/f2fs/inode.c:986
 f2fs_create+0x357/0x530 fs/f2fs/namei.c:394
 lookup_open fs/namei.c:3595 [inline]
 open_last_lookups fs/namei.c:3694 [inline]
 path_openat+0x1c03/0x3590 fs/namei.c:3930
 do_filp_open+0x235/0x490 fs/namei.c:3960
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_openat fs/open.c:1446 [inline]
 __se_sys_openat fs/open.c:1441 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0010:f2fs_invalidate_blocks+0x35f/0x370 fs/f2fs/segment.c:2534

The root cause is: on a fuzzed image, blkaddr in nat entry may be
corrupted, then it will cause system panic when using it in
f2fs_invalidate_blocks(), to avoid this, let's add sanity check on
nat blkaddr in truncate_node().

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions)

## Which versions are affected by CVE-2024-56692?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56692?

Apply the vendor's patch.

## Is CVE-2024-56692 being exploited?

There is no known exploitation of CVE-2024-56692 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-2024-56692 and fix it if it is affected.

What it is: CVE-2024-56692 is a high-severity denial of service vulnerability in Linux kernel, published on 28 Dec 2024. 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-2024-56692 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-2024-56692/ (Markdown: https://insights.sbomify.com/CVE-2024-56692/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56692
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56692
- OSV: https://osv.dev/vulnerability/CVE-2024-56692

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56692/
Summaries are generated and may contain mistakes; the official description above is the record.