# CVE-2024-56717: net: mscc: ocelot: fix incorrect IFH SRC_PORT field in ocelot_ifh_set_basic()

> Incorrect port index handling in the Ocelot network driver causes kernel warnings and transmission timeouts, potentially leading to denial of service.

- **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:** 29 Dec 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-55437, BELL-CVE-2024-56717, DEBIAN-CVE-2024-56717, GHSA-c7fp-8j89-w969, ROOT-OS-UBUNTU-2204-CVE-2024-56717, UBUNTU-CVE-2024-56717

## What is CVE-2024-56717?

CVE-2024-56717 is a high-severity vulnerability in Linux kernel, published on 29 Dec 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: mscc: ocelot: fix incorrect IFH SRC_PORT field in ocelot_ifh_set_basic()

Packets injected by the CPU should have a SRC_PORT field equal to the
CPU port module index in the Analyzer block (ocelot->num_phys_ports).

The blamed commit copied the ocelot_ifh_set_basic() call incorrectly
from ocelot_xmit_common() in net/dsa/tag_ocelot.c. Instead of calling
with "x", it calls with BIT_ULL(x), but the field is not a port mask,
but rather a single port index.

[ side note: this is the technical debt of code duplication :( ]

The error used to be silent and doesn't appear to have other
user-visible manifestations, but with new changes in the packing
library, it now fails loudly as follows:

------------[ cut here ]------------
Cannot store 0x40 inside bits 46-43 - will truncate
sja1105 spi2.0: xmit timed out
WARNING: CPU: 1 PID: 102 at lib/packing.c:98 __pack+0x90/0x198
sja1105 spi2.0: timed out polling for tstamp
CPU: 1 UID: 0 PID: 102 Comm: felix_xmit
Tainted: G        W        N 6.13.0-rc1-00372-gf706b85d972d-dirty #2605
Call trace:
 __pack+0x90/0x198 (P)
 __pack+0x90/0x198 (L)
 packing+0x78/0x98
 ocelot_ifh_set_basic+0x260/0x368
 ocelot_port_inject_frame+0xa8/0x250
 felix_port_deferred_xmit+0x14c/0x258
 kthread_worker_fn+0x134/0x350
 kthread+0x114/0x138

The code path pertains to the ocelot switchdev driver and to the felix
secondary DSA tag protocol, ocelot-8021q. Here seen with ocelot-8021q.

The messenger (packing) is not really to blame, so fix the original
commit instead.

## Which versions are affected by CVE-2024-56717?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56717?

Apply the vendor's patch.

## Is CVE-2024-56717 being exploited?

There is no known exploitation of CVE-2024-56717 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-2024-56717 and fix it if it is affected.

What it is: CVE-2024-56717 is a high-severity vulnerability in Linux kernel, published on 29 Dec 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-2024-56717 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-2024-56717/ (Markdown: https://insights.sbomify.com/CVE-2024-56717/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56717
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56717
- OSV: https://osv.dev/vulnerability/CVE-2024-56717

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56717/
Summaries are generated and may contain mistakes; the official description above is the record.