# CVE-2021-47619: i40e: Fix queues reservation for XDP

> A local attacker with network configuration privileges can cause a kernel crash via NULL pointer dereference in the i40e driver when configuring XDP on specific hardware.

- **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:** 20 Jun 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-47619, GHSA-cw86-cw6h-wc44, UBUNTU-CVE-2021-47619

## What is CVE-2021-47619?

CVE-2021-47619 is a medium-severity vulnerability in Linux kernel, published on 20 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:

i40e: Fix queues reservation for XDP

When XDP was configured on a system with large number of CPUs
and X722 NIC there was a call trace with NULL pointer dereference.

i40e 0000:87:00.0: failed to get tracking for 256 queues for VSI 0 err -12
i40e 0000:87:00.0: setup of MAIN VSI failed

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:i40e_xdp+0xea/0x1b0 [i40e]
Call Trace:
? i40e_reconfig_rss_queues+0x130/0x130 [i40e]
dev_xdp_install+0x61/0xe0
dev_xdp_attach+0x18a/0x4c0
dev_change_xdp_fd+0x1e6/0x220
do_setlink+0x616/0x1030
? ahci_port_stop+0x80/0x80
? ata_qc_issue+0x107/0x1e0
? lock_timer_base+0x61/0x80
? __mod_timer+0x202/0x380
rtnl_setlink+0xe5/0x170
? bpf_lsm_binder_transaction+0x10/0x10
? security_capable+0x36/0x50
rtnetlink_rcv_msg+0x121/0x350
? rtnl_calcit.isra.0+0x100/0x100
netlink_rcv_skb+0x50/0xf0
netlink_unicast+0x1d3/0x2a0
netlink_sendmsg+0x22a/0x440
sock_sendmsg+0x5e/0x60
__sys_sendto+0xf0/0x160
? __sys_getsockname+0x7e/0xc0
? _copy_from_user+0x3c/0x80
? __sys_setsockopt+0xc8/0x1a0
__x64_sys_sendto+0x20/0x30
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f83fa7a39e0

This was caused by PF queue pile fragmentation due to
flow director VSI queue being placed right after main VSI.
Because of this main VSI was not able to resize its
queue allocation for XDP resulting in no queues allocated
for main VSI when XDP was turned on.

Fix this by always allocating last queue in PF queue pile
for a flow director VSI.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2021-47619?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47619?

Apply the vendor's patch.

## Is CVE-2021-47619 being exploited?

There is no known exploitation of CVE-2021-47619 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-2021-47619 and fix it if it is affected.

What it is: CVE-2021-47619 is a medium-severity vulnerability in Linux kernel, published on 20 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-2021-47619 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-2021-47619/ (Markdown: https://insights.sbomify.com/CVE-2021-47619/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47619
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47619
- OSV: https://osv.dev/vulnerability/CVE-2021-47619

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47619/
Summaries are generated and may contain mistakes; the official description above is the record.