CVE-2021-47170: linux kernel DoS — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: USB: usbfs: Don't WARN about excessively large memory allocations Syzbot found that the kernel generates a WARNing if the user tries to submit a bulk transfer through usbfs with a buffer that is way too large. This isn't a bug in the kernel; it's merely an invalid request from the user and the usbfs code does handle it correctly. In theory the same thing can happen with async transfers, or with the packet descriptor table for isochronous transfers. To prevent the MM subsystem from complaining about these bad allocation requests, add the __GFP_NOWARN flag to the kmalloc calls for these buffers.

Is your site exposed to CVE-2021-47170?

Run a free security scan — no signup, results in seconds.

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	< 4.19.193
linux	linux_kernel	4.20 — 5.4.124
linux	linux_kernel	5.5 — 5.10.42
linux	linux_kernel	5.11 — 5.12.9
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

Frequently Asked Questions

What is CVE-2021-47170? +

In the Linux kernel, the following vulnerability has been resolved: USB: usbfs: Don't WARN about excessively large memory allocations Syzbot found that the kernel generates a WARNing if the user tries to submit a bulk transfer through usbfs with a buffer that is way too large. This isn't a bug in the kernel; it's merely an invalid request from the user and the usbfs code does handle it correctly. In theory the same thing can happen with async transfers, or with the packet descriptor table for isochronous transfers. To prevent the MM subsystem from complaining about these bad allocation requests, add the __GFP_NOWARN flag to the kmalloc calls for these buffers. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2021-47170? +

CVE-2021-47170 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-2021-47170? +

CVE-2021-47170 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-2021-47170? +

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.

Related Vulnerabilities

CVE-2026-39313

mcp-framework is a framework for building Model Context Protocol (MCP) servers. In versions 0.2.21 and below, the readRequestBody() function in …

CVE-2026-35469

spdystream is a Go library for multiplexing streams over SPDY connections. In versions 0.5.0 and below, the SPDY/3 frame parser …

CVE-2026-39803

Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated remote denial of service via memory exhaustion. …

CVE-2026-39804

Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated remote denial of service via memory exhaustion …

CVE-2026-32688

Allocation of Resources Without Limits or Throttling vulnerability in elixir-plug plug_cowboy allows unauthenticated remote denial of service via atom table …

CVE-2026-10573

A denial-of-service security issue exists in 1734 POINT I/O™ module. The security issue stems from improper handling of crafted CIP …

CVE-2021-47170