# CVE-2021-46980: usb: typec: ucsi: Retrieve all the PDOs instead of just the first 4

> An out-of-bounds read in the Linux kernel USB Type-C driver can cause a system crash when connecting to specific power sources.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 28 Feb 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-46980, GHSA-g32h-2c9h-xpxj, UBUNTU-CVE-2021-46980

## What is CVE-2021-46980?

CVE-2021-46980 is a high-severity memory corruption vulnerability in Linux kernel, published on 28 Feb 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:

usb: typec: ucsi: Retrieve all the PDOs instead of just the first 4

commit 4dbc6a4ef06d ("usb: typec: ucsi: save power data objects
in PD mode") introduced retrieval of the PDOs when connected to a
PD-capable source. But only the first 4 PDOs are received since
that is the maximum number that can be fetched at a time given the
MESSAGE_IN length limitation (16 bytes). However, as per the PD spec
a connected source may advertise up to a maximum of 7 PDOs.

If such a source is connected it's possible the PPM could have
negotiated a power contract with one of the PDOs at index greater
than 4, and would be reflected in the request data object's (RDO)
object position field. This would result in an out-of-bounds access
when the rdo_index() is used to index into the src_pdos array in
ucsi_psy_get_voltage_now().

With the help of the UBSAN -fsanitize=array-bounds checker enabled
this exact issue is revealed when connecting to a PD source adapter
that advertise 5 PDOs and the PPM enters a contract having selected
the 5th one.

[  151.545106][   T70] Unexpected kernel BRK exception at EL1
[  151.545112][   T70] Internal error: BRK handler: f2005512 [#1] PREEMPT SMP
...
[  151.545499][   T70] pc : ucsi_psy_get_prop+0x208/0x20c
[  151.545507][   T70] lr : power_supply_show_property+0xc0/0x328
...
[  151.545542][   T70] Call trace:
[  151.545544][   T70]  ucsi_psy_get_prop+0x208/0x20c
[  151.545546][   T70]  power_supply_uevent+0x1a4/0x2f0
[  151.545550][   T70]  dev_uevent+0x200/0x384
[  151.545555][   T70]  kobject_uevent_env+0x1d4/0x7e8
[  151.545557][   T70]  power_supply_changed_work+0x174/0x31c
[  151.545562][   T70]  process_one_work+0x244/0x6f0
[  151.545564][   T70]  worker_thread+0x3e0/0xa64

We can resolve this by instead retrieving and storing up to the
maximum of 7 PDOs in the con->src_pdos array. This would involve
two calls to the GET_PDOS command.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2021-46980?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-46980?

Apply the vendor's patch.

## Is CVE-2021-46980 being exploited?

There is no known exploitation of CVE-2021-46980 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-2021-46980 and fix it if it is affected.

What it is: CVE-2021-46980 is a high-severity memory corruption vulnerability in Linux kernel, published on 28 Feb 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-2021-46980 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-2021-46980/ (Markdown: https://insights.sbomify.com/CVE-2021-46980/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-46980
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-46980
- OSV: https://osv.dev/vulnerability/CVE-2021-46980

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-46980/
Summaries are generated and may contain mistakes; the official description above is the record.