# CVE-2024-26690: net: stmmac: protect updates of 64-bit statistics counters

> A race condition in the stmmac network driver can cause system lockups on 32-bit platforms due to unsynchronized 64-bit counter updates.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Apr 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-26690, DEBIAN-CVE-2024-26690, GHSA-5c46-ggmc-6j5m, UBUNTU-CVE-2024-26690

## What is CVE-2024-26690?

CVE-2024-26690 is a high-severity vulnerability in Linux kernel, published on 3 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

net: stmmac: protect updates of 64-bit statistics counters

As explained by a comment in <linux/u64_stats_sync.h>, write side of struct
u64_stats_sync must ensure mutual exclusion, or one seqcount update could
be lost on 32-bit platforms, thus blocking readers forever. Such lockups
have been observed in real world after stmmac_xmit() on one CPU raced with
stmmac_napi_poll_tx() on another CPU.

To fix the issue without introducing a new lock, split the statics into
three parts:

1. fields updated only under the tx queue lock,
2. fields updated only during NAPI poll,
3. fields updated only from interrupt context,

Updates to fields in the first two groups are already serialized through
other locks. It is sufficient to split the existing struct u64_stats_sync
so that each group has its own.

Note that tx_set_ic_bit is updated from both contexts. Split this counter
so that each context gets its own, and calculate their sum to get the total
value in stmmac_get_ethtool_stats().

For the third group, multiple interrupts may be processed by different CPUs
at the same time, but interrupts on the same CPU will not nest. Move fields
from this group to a newly created per-cpu struct stmmac_pcpu_stats.

## Which versions are affected by CVE-2024-26690?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-26690?

Apply the vendor's patch.

## Is CVE-2024-26690 being exploited?

There is no known exploitation of CVE-2024-26690 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-2024-26690 and fix it if it is affected.

What it is: CVE-2024-26690 is a high-severity vulnerability in Linux kernel, published on 3 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-26690 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-2024-26690/ (Markdown: https://insights.sbomify.com/CVE-2024-26690/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-26690
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-26690
- OSV: https://osv.dev/vulnerability/CVE-2024-26690

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-26690/
Summaries are generated and may contain mistakes; the official description above is the record.