# CVE-2021-47612: nfc: fix segfault in nfc_genl_dump_devices_done

> A null pointer dereference in the Linux kernel NFC subsystem allows local attackers to cause a system crash via a failed memory allocation.

- **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:** 19 Jun 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-47612, GHSA-7vv8-23mh-rqfj, UBUNTU-CVE-2021-47612

## What is CVE-2021-47612?

CVE-2021-47612 is a medium-severity vulnerability in Linux kernel, published on 19 Jun 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:

nfc: fix segfault in nfc_genl_dump_devices_done

When kmalloc in nfc_genl_dump_devices() fails then
nfc_genl_dump_devices_done() segfaults as below

KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 25 Comm: kworker/0:1 Not tainted 5.16.0-rc4-01180-g2a987e65025e-dirty #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-6.fc35 04/01/2014
Workqueue: events netlink_sock_destruct_work
RIP: 0010:klist_iter_exit+0x26/0x80
Call Trace:
<TASK>
class_dev_iter_exit+0x15/0x20
nfc_genl_dump_devices_done+0x3b/0x50
genl_lock_done+0x84/0xd0
netlink_sock_destruct+0x8f/0x270
__sk_destruct+0x64/0x3b0
sk_destruct+0xa8/0xd0
__sk_free+0x2e8/0x3d0
sk_free+0x51/0x90
netlink_sock_destruct_work+0x1c/0x20
process_one_work+0x411/0x710
worker_thread+0x6fd/0xa80

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2021-47612?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47612?

Apply the vendor's patch.

## Is CVE-2021-47612 being exploited?

There is no known exploitation of CVE-2021-47612 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-2021-47612 and fix it if it is affected.

What it is: CVE-2021-47612 is a medium-severity vulnerability in Linux kernel, published on 19 Jun 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-2021-47612 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-2021-47612/ (Markdown: https://insights.sbomify.com/CVE-2021-47612/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47612
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47612
- OSV: https://osv.dev/vulnerability/CVE-2021-47612

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47612/
Summaries are generated and may contain mistakes; the official description above is the record.