CVE-2021-47511 ALSA: pcm: oss: Fix negative period/buffer sizes

What is CVE-2021-47511?

CVE-2021-47511 is a medium-severity 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:

ALSA: pcm: oss: Fix negative period/buffer sizes

The period size calculation in OSS layer may receive a negative value as an error, but the code there assumes only the positive values and handle them with size_t. Due to that, a too big value may be passed to the lower layers.

This patch changes the code to handle with ssize_t and adds the proper error checks appropriately.

Which versions are affected by CVE-2021-47511?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47511?

Apply the vendor's patch.

Is CVE-2021-47511 being exploited?

There is no known exploitation of CVE-2021-47511 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-2021-47511, UBUNTU-CVE-2021-47511.