# CVE-2022-50063: net: dsa: felix: suppress non-changes to the tagging protocol

> A null pointer dereference in the Linux kernel's felix DSA driver allows local attackers to crash the system by triggering a specific tagging protocol error.

- **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:** 18 Jun 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-50063, GHSA-vhwp-83w8-m7pm, UBUNTU-CVE-2022-50063

## What is CVE-2022-50063?

CVE-2022-50063 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 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:

net: dsa: felix: suppress non-changes to the tagging protocol

The way in which dsa_tree_change_tag_proto() works is that when
dsa_tree_notify() fails, it doesn't know whether the operation failed
mid way in a multi-switch tree, or it failed for a single-switch tree.
So even though drivers need to fail cleanly in
ds->ops->change_tag_protocol(), DSA will still call dsa_tree_notify()
again, to restore the old tag protocol for potential switches in the
tree where the change did succeeed (before failing for others).

This means for the felix driver that if we report an error in
felix_change_tag_protocol(), we'll get another call where proto_ops ==
old_proto_ops. If we proceed to act upon that, we may do unexpected
things. For example, we will call dsa_tag_8021q_register() twice in a
row, without any dsa_tag_8021q_unregister() in between. Then we will
actually call dsa_tag_8021q_unregister() via old_proto_ops->teardown,
which (if it manages to run at all, after walking through corrupted data
structures) will leave the ports inoperational anyway.

The bug can be readily reproduced if we force an error while in
tag_8021q mode; this crashes the kernel.

echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging
echo edsa > /sys/class/net/eno2/dsa/tagging # -EPROTONOSUPPORT

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000014
Call trace:
 vcap_entry_get+0x24/0x124
 ocelot_vcap_filter_del+0x198/0x270
 felix_tag_8021q_vlan_del+0xd4/0x21c
 dsa_switch_tag_8021q_vlan_del+0x168/0x2cc
 dsa_switch_event+0x68/0x1170
 dsa_tree_notify+0x14/0x34
 dsa_port_tag_8021q_vlan_del+0x84/0x110
 dsa_tag_8021q_unregister+0x15c/0x1c0
 felix_tag_8021q_teardown+0x16c/0x180
 felix_change_tag_protocol+0x1bc/0x230
 dsa_switch_event+0x14c/0x1170
 dsa_tree_change_tag_proto+0x118/0x1c0

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-50063?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-50063?

Apply the vendor's patch.

## Is CVE-2022-50063 being exploited?

There is no known exploitation of CVE-2022-50063 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-2022-50063 and fix it if it is affected.

What it is: CVE-2022-50063 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 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-2022-50063 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-2022-50063/ (Markdown: https://insights.sbomify.com/CVE-2022-50063/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50063
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50063
- OSV: https://osv.dev/vulnerability/CVE-2022-50063

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50063/
Summaries are generated and may contain mistakes; the official description above is the record.