# CVE-2024-26725: dpll: fix possible deadlock during netlink dump operation

> A deadlock in the Linux kernel DPLL subsystem during netlink dump operations can cause 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:** 3 Apr 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2024-26725, DEBIAN-CVE-2024-26725, GHSA-jgpw-6hf2-c2m5, UBUNTU-CVE-2024-26725

## What is CVE-2024-26725?

CVE-2024-26725 is a medium-severity vulnerability in Linux kernel, published on 3 Apr 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:

dpll: fix possible deadlock during netlink dump operation

Recently, I've been hitting following deadlock warning during dpll pin
dump:

[52804.637962] ======================================================
[52804.638536] WARNING: possible circular locking dependency detected
[52804.639111] 6.8.0-rc2jiri+ #1 Not tainted
[52804.639529] ------------------------------------------------------
[52804.640104] python3/2984 is trying to acquire lock:
[52804.640581] ffff88810e642678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: netlink_dump+0xb3/0x780
[52804.641417]
               but task is already holding lock:
[52804.642010] ffffffff83bde4c8 (dpll_lock){+.+.}-{3:3}, at: dpll_lock_dumpit+0x13/0x20
[52804.642747]
               which lock already depends on the new lock.

[52804.643551]
               the existing dependency chain (in reverse order) is:
[52804.644259]
               -> #1 (dpll_lock){+.+.}-{3:3}:
[52804.644836]        lock_acquire+0x174/0x3e0
[52804.645271]        __mutex_lock+0x119/0x1150
[52804.645723]        dpll_lock_dumpit+0x13/0x20
[52804.646169]        genl_start+0x266/0x320
[52804.646578]        __netlink_dump_start+0x321/0x450
[52804.647056]        genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.647575]        genl_rcv_msg+0x1ed/0x3b0
[52804.648001]        netlink_rcv_skb+0xdc/0x210
[52804.648440]        genl_rcv+0x24/0x40
[52804.648831]        netlink_unicast+0x2f1/0x490
[52804.649290]        netlink_sendmsg+0x36d/0x660
[52804.649742]        __sock_sendmsg+0x73/0xc0
[52804.650165]        __sys_sendto+0x184/0x210
[52804.650597]        __x64_sys_sendto+0x72/0x80
[52804.651045]        do_syscall_64+0x6f/0x140
[52804.651474]        entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.652001]
               -> #0 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}:
[52804.652650]        check_prev_add+0x1ae/0x1280
[52804.653107]        __lock_acquire+0x1ed3/0x29a0
[52804.653559]        lock_acquire+0x174/0x3e0
[52804.653984]        __mutex_lock+0x119/0x1150
[52804.654423]        netlink_dump+0xb3/0x780
[52804.654845]        __netlink_dump_start+0x389/0x450
[52804.655321]        genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.655842]        genl_rcv_msg+0x1ed/0x3b0
[52804.656272]        netlink_rcv_skb+0xdc/0x210
[52804.656721]        genl_rcv+0x24/0x40
[52804.657119]        netlink_unicast+0x2f1/0x490
[52804.657570]        netlink_sendmsg+0x36d/0x660
[52804.658022]        __sock_sendmsg+0x73/0xc0
[52804.658450]        __sys_sendto+0x184/0x210
[52804.658877]        __x64_sys_sendto+0x72/0x80
[52804.659322]        do_syscall_64+0x6f/0x140
[52804.659752]        entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.660281]
               other info that might help us debug this:

[52804.661077]  Possible unsafe locking scenario:

[52804.661671]        CPU0                    CPU1
[52804.662129]        ----                    ----
[52804.662577]   lock(dpll_lock);
[52804.662924]                                lock(nlk_cb_mutex-GENERIC);
[52804.663538]                                lock(dpll_lock);
[52804.664073]   lock(nlk_cb_mutex-GENERIC);
[52804.664490]

The issue as follows: __netlink_dump_start() calls control->start(cb)
with nlk->cb_mutex held. In control->start(cb) the dpll_lock is taken.
Then nlk->cb_mutex is released and taken again in netlink_dump(), while
dpll_lock still being held. That leads to ABBA deadlock when another
CPU races with the same operation.

Fix this by moving dpll_lock taking into dumpit() callback which ensures
correct lock taking order.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2024-26725?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-26725?

Apply the vendor's patch.

## Is CVE-2024-26725 being exploited?

There is no known exploitation of CVE-2024-26725 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-2024-26725 and fix it if it is affected.

What it is: CVE-2024-26725 is a medium-severity vulnerability in Linux kernel, published on 3 Apr 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-2024-26725 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-2024-26725/ (Markdown: https://insights.sbomify.com/CVE-2024-26725/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-26725
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-26725
- OSV: https://osv.dev/vulnerability/CVE-2024-26725

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-26725/
Summaries are generated and may contain mistakes; the official description above is the record.