CVE-2021-47514 devlink: fix netns refcount leak in devlink_nl_cmd_reload()

What is CVE-2021-47514?

CVE-2021-47514 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 May 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:

devlink: fix netns refcount leak in devlink_nl_cmd_reload()

While preparing my patch series adding netns refcount tracking, I spotted bugs in devlink_nl_cmd_reload()

Some error paths forgot to release a refcount on a netns.

To fix this, we can reduce the scope of get_net()/put_net() section around the call to devlink_reload().

Which versions are affected by CVE-2021-47514?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47514?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-47514 being exploited?

There is no known exploitation of CVE-2021-47514 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• How this page is made

Also known as DEBIAN-CVE-2021-47514, UBUNTU-CVE-2021-47514.