Linux Kernel up to 5.12.9 io_uring io_link_timeout_fn use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.1$0-$5k0.00

Summaryinfo

A vulnerability labeled as problematic has been found in Linux Kernel up to 5.12.9. The impacted element is the function io_link_timeout_fn of the component io_uring. The manipulation results in use after free. This vulnerability is reported as CVE-2021-47123. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 5.12.9. Affected is the function io_link_timeout_fn of the component io_uring. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: io_uring: fix ltout double free on completion race Always remove linked timeout on io_link_timeout_fn() from the master request link list, otherwise we may get use-after-free when first io_link_timeout_fn() puts linked timeout in the fail path, and then will be found and put on master's free.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2021-47123 since 03/04/2024. The exploitability is told to be difficult. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 01/14/2025).

Upgrading to version 5.12.10 or 5.13 eliminates this vulnerability. Applying the patch 1f64f5e903b9/447c19f3b507 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.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.2
VulDB Meta Temp Score: 6.1

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.12.10/5.13
Patch: 1f64f5e903b9/447c19f3b507

Timelineinfo

03/04/2024 🔍
03/15/2024 +11 days 🔍
03/15/2024 +0 days 🔍
01/14/2025 +305 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2021-47123 (🔍)
GCVE (CVE): GCVE-0-2021-47123
GCVE (VulDB): GCVE-100-257022

Entryinfo

Created: 03/15/2024 22:51
Updated: 01/14/2025 17:15
Changes: 03/15/2024 22:51 (43), 01/14/2025 17:15 (27)
Complete: 🔍
Cache ID: 216::103

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