# CVE-2021-47180: NFC: nci: fix memory leak in nci_allocate_device

> A memory leak in the Linux kernel NFC subsystem allows attackers to cause a denial of service by exhausting kernel memory.

- **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:** 25 Mar 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-47180, GHSA-jwrw-gr4p-2mx9, UBUNTU-CVE-2021-47180

## What is CVE-2021-47180?

CVE-2021-47180 is a medium-severity memory corruption vulnerability in Linux kernel, published on 25 Mar 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: nci: fix memory leak in nci_allocate_device

nfcmrvl_disconnect fails to free the hci_dev field in struct nci_dev.
Fix this by freeing hci_dev in nci_free_device.

BUG: memory leak
unreferenced object 0xffff888111ea6800 (size 1024):
  comm "kworker/1:0", pid 19, jiffies 4294942308 (age 13.580s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 60 fd 0c 81 88 ff ff  .........`......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000004bc25d43>] kmalloc include/linux/slab.h:552 [inline]
    [<000000004bc25d43>] kzalloc include/linux/slab.h:682 [inline]
    [<000000004bc25d43>] nci_hci_allocate+0x21/0xd0 net/nfc/nci/hci.c:784
    [<00000000c59cff92>] nci_allocate_device net/nfc/nci/core.c:1170 [inline]
    [<00000000c59cff92>] nci_allocate_device+0x10b/0x160 net/nfc/nci/core.c:1132
    [<00000000006e0a8e>] nfcmrvl_nci_register_dev+0x10a/0x1c0 drivers/nfc/nfcmrvl/main.c:153
    [<000000004da1b57e>] nfcmrvl_probe+0x223/0x290 drivers/nfc/nfcmrvl/usb.c:345
    [<00000000d506aed9>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396
    [<00000000bc632c92>] really_probe+0x159/0x4a0 drivers/base/dd.c:554
    [<00000000f5009125>] driver_probe_device+0x84/0x100 drivers/base/dd.c:740
    [<000000000ce658ca>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:846
    [<000000007067d05f>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
    [<00000000f8e13372>] __device_attach+0x122/0x250 drivers/base/dd.c:914
    [<000000009cf68860>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491
    [<00000000359c965a>] device_add+0x5be/0xc30 drivers/base/core.c:3109
    [<00000000086e4bd3>] usb_set_configuration+0x9d9/0xb90 drivers/usb/core/message.c:2164
    [<00000000ca036872>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238
    [<00000000d40d36f6>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293
    [<00000000bc632c92>] really_probe+0x159/0x4a0 drivers/base/dd.c:554

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2021-47180?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47180?

Apply the vendor's patch.

## Is CVE-2021-47180 being exploited?

There is no known exploitation of CVE-2021-47180 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-2021-47180 and fix it if it is affected.

What it is: CVE-2021-47180 is a medium-severity memory corruption vulnerability in Linux kernel, published on 25 Mar 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-2021-47180 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-2021-47180/ (Markdown: https://insights.sbomify.com/CVE-2021-47180/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47180
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47180
- OSV: https://osv.dev/vulnerability/CVE-2021-47180

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47180/
Summaries are generated and may contain mistakes; the official description above is the record.
