CVE-2021-47374: linux kernel DoS — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: dma-debug: prevent an error message from causing runtime problems For some drivers, that use the DMA API. This error message can be reached several millions of times per second, causing spam to the kernel's printk buffer and bringing the CPU usage up to 100% (so, it should be rate limited). However, since there is at least one driver that is in the mainline and suffers from the error condition, it is more useful to err_printk() here instead of just rate limiting the error message (in hopes that it will make it easier for other drivers that suffer from this issue to be spotted).

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-770 CWE-770

Affected Products

Vendor	Product	Versions
linux	linux_kernel	< 5.14.9
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/510e1a724ab1bf38150be2c1acabb303f98d0047 https://git.kernel.org/stable/c/de4afec2d2946c92c62a15ab341c70b287289e6a https://git.kernel.org/stable/c/510e1a724ab1bf38150be2c1acabb303f98d0047 https://git.kernel.org/stable/c/de4afec2d2946c92c62a15ab341c70b287289e6a

Frequently Asked Questions

What is CVE-2021-47374? +

In the Linux kernel, the following vulnerability has been resolved: dma-debug: prevent an error message from causing runtime problems For some drivers, that use the DMA API. This error message can be reached several millions of times per second, causing spam to the kernel's printk buffer and bringing the CPU usage up to 100% (so, it should be rate limited). However, since there is at least one driver that is in the mainline and suffers from the error condition, it is more useful to err_printk() here instead of just rate limiting the error message (in hopes that it will make it easier for other drivers that suffer from this issue to be spotted). It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2021-47374? +

CVE-2021-47374 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2021-47374? +

CVE-2021-47374 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2021-47374? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2021-47374