# CVE-2024-56774: btrfs: add a sanity check for btrfs root in btrfs_search_slot()

> A null pointer dereference in the Linux kernel btrfs filesystem can cause a denial of service when using rescue mode with corrupted extent trees.

- **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:** 8 Jan 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-55334, AZL-55369, BELL-CVE-2024-56774, DEBIAN-CVE-2024-56774, GHSA-phf7-cpqm-749x, UBUNTU-CVE-2024-56774

## What is CVE-2024-56774?

CVE-2024-56774 is a medium-severity vulnerability in Linux kernel, published on 8 Jan 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:

btrfs: add a sanity check for btrfs root in btrfs_search_slot()

Syzbot reports a null-ptr-deref in btrfs_search_slot().

The reproducer is using rescue=ibadroots, and the extent tree root is
corrupted thus the extent tree is NULL.

When scrub tries to search the extent tree to gather the needed extent
info, btrfs_search_slot() doesn't check if the target root is NULL or
not, resulting the null-ptr-deref.

Add sanity check for btrfs root before using it in btrfs_search_slot().

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-56774?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56774?

Apply the vendor's patch.

## Is CVE-2024-56774 being exploited?

There is no known exploitation of CVE-2024-56774 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-2024-56774 and fix it if it is affected.

What it is: CVE-2024-56774 is a medium-severity vulnerability in Linux kernel, published on 8 Jan 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-2024-56774 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-2024-56774/ (Markdown: https://insights.sbomify.com/CVE-2024-56774/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56774
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56774
- OSV: https://osv.dev/vulnerability/CVE-2024-56774

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56774/
Summaries are generated and may contain mistakes; the official description above is the record.