CVE-2021-47339 media: v4l2-core: explicitly clear ioctl input data

What is CVE-2021-47339?

CVE-2021-47339 is a medium-severity vulnerability in Linux kernel, published on 21 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:

media: v4l2-core: explicitly clear ioctl input data

As seen from a recent syzbot bug report, mistakes in the compat ioctl implementation can lead to uninitialized kernel stack data getting used as input for driver ioctl handlers.

The reported bug is now fixed, but it's possible that other related bugs are still present or get added in the future. As the drivers need to check user input already, the possible impact is fairly low, but it might still cause an information leak.

To be on the safe side, always clear the entire ioctl buffer before calling the conversion handler functions that are meant to initialize them.

Weakness: CWE-908

Which versions are affected by CVE-2021-47339?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47339?

Apply the vendor's patch.

Is CVE-2021-47339 being exploited?

There is no known exploitation of CVE-2021-47339 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
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-47339, GHSA-3p2v-4qj8-6w5f, ROOT-OS-DEBIAN-11-CVE-2021-47339, UBUNTU-CVE-2021-47339.