# CVE-2025-37918: Bluetooth: btusb: avoid NULL pointer dereference in skb_dequeue()

> A NULL pointer dereference in the Linux kernel Bluetooth driver allows local attackers to cause a system crash via crafted firmware crash dumps.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 May 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2025-37918, DEBIAN-CVE-2025-37918, GHSA-qjmq-chg2-32xr, ROOT-OS-UBUNTU-2404-CVE-2025-37918, UBUNTU-CVE-2025-37918

## What is CVE-2025-37918?

CVE-2025-37918 is a high-severity vulnerability in Linux kernel, published on 20 May 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:

Bluetooth: btusb: avoid NULL pointer dereference in skb_dequeue()

A NULL pointer dereference can occur in skb_dequeue() when processing a
QCA firmware crash dump on WCN7851 (0489:e0f3).

[ 93.672166] Bluetooth: hci0: ACL memdump size(589824)

[ 93.672475] BUG: kernel NULL pointer dereference, address: 0000000000000008
[ 93.672517] Workqueue: hci0 hci_devcd_rx [bluetooth]
[ 93.672598] RIP: 0010:skb_dequeue+0x50/0x80

The issue stems from handle_dump_pkt_qca() returning 0 even when a dump
packet is successfully processed. This is because it incorrectly
forwards the return value of hci_devcd_init() (which returns 0 on
success). As a result, the caller (btusb_recv_acl_qca() or
btusb_recv_evt_qca()) assumes the packet was not handled and passes it
to hci_recv_frame(), leading to premature kfree() of the skb.

Later, hci_devcd_rx() attempts to dequeue the same skb from the dump
queue, resulting in a NULL pointer dereference.

Fix this by:
1. Making handle_dump_pkt_qca() return 0 on success and negative errno
   on failure, consistent with kernel conventions.
2. Splitting dump packet detection into separate functions for ACL
   and event packets for better structure and readability.

This ensures dump packets are properly identified and consumed, avoiding
double handling and preventing NULL pointer access.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-37918?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-37918?

Apply the vendor's patch.

## Is CVE-2025-37918 being exploited?

There is no known exploitation of CVE-2025-37918 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-2025-37918 and fix it if it is affected.

What it is: CVE-2025-37918 is a high-severity vulnerability in Linux kernel, published on 20 May 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-2025-37918 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-2025-37918/ (Markdown: https://insights.sbomify.com/CVE-2025-37918/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37918
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37918
- OSV: https://osv.dev/vulnerability/CVE-2025-37918

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37918/
Summaries are generated and may contain mistakes; the official description above is the record.