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

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-21 · updated 2026-06-17
Weakness: CWE-908

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.

Affected products

Linux kernel: before 5.12.18; from 5.13 before 5.13.3 — fixed in 5.12.18, 5.13.3

How to fix

Upgrade to a fixed version: Linux kernel 5.12.18, 5.13.3. Check the vendor advisory for mitigations.

References

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