VDB-265904 · CVE-2021-47498 · EUVD-2021-34502

Linux Kernel up to 5.14.13 unquiesce nr_requests denial of service

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5.5	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 5.14.13. Affected by this issue is the function nr_requests of the component unquiesce. Such manipulation leads to denial of service. This vulnerability is traded as CVE-2021-47498. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.14.13. It has been rated as critical. Affected by this issue is the function nr_requests of the component unquiesce. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: dm rq: don't queue request to blk-mq during DM suspend DM uses blk-mq's quiesce/unquiesce to stop/start device mapper queue. But blk-mq's unquiesce may come from outside events, such as elevator switch, updating nr_requests or others, and request may come during suspend, so simply ask for blk-mq to requeue it. Fixes one kernel panic issue when running updating nr_requests and dm-mpath suspend/resume stress test.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2021-47498 since 05/22/2024. There are known technical details, but no exploit is available.

Upgrading to version 5.14.14 eliminates this vulnerability. Applying the patch 8ca9745efe35/b4459b11e840 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2021-34502). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.14.14
Patch: 8ca9745efe35/b4459b11e840

Timelineinfo

05/22/2024 🔍
05/22/2024 +0 days 🔍
05/22/2024 +0 days 🔍
12/10/2025 +567 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2021-47498 (🔍)
GCVE (CVE): GCVE-0-2021-47498
GCVE (VulDB): GCVE-100-265904
EUVD: 🔍

Entryinfo

Created: 05/22/2024 11:43
Updated: 12/10/2025 11:42
Changes: 05/22/2024 11:43 (58), 04/02/2025 06:38 (2), 12/10/2025 11:42 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.