CVE-2021-47476 comedi: ni_usb6501: fix NULL-deref in command paths

What is CVE-2021-47476?

CVE-2021-47476 is a medium-severity vulnerability in Linux kernel, published on 22 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:

comedi: ni_usb6501: fix NULL-deref in command paths

The driver uses endpoint-sized USB transfer buffers but had no sanity checks on the sizes. This can lead to zero-size-pointer dereferences or overflowed transfer buffers in ni6501_port_command() and ni6501_counter_command() if a (malicious) device has smaller max-packet sizes than expected (or when doing descriptor fuzz testing).

Add the missing sanity checks to probe().

Weakness: CWE-476

Which versions are affected by CVE-2021-47476?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47476?

Apply the vendor's patch.

Is CVE-2021-47476 being exploited?

There is no known exploitation of CVE-2021-47476 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-2021-47476, GHSA-c84w-j8mj-57ch, UBUNTU-CVE-2021-47476.