Linux Kernel up to 5.13.4 free_netdev use after free

Summaryinfo

A vulnerability classified as problematic was found in Linux Kernel up to 5.13.4. Affected by this vulnerability is the function free_netdev. Such manipulation leads to use after free. This vulnerability is documented as CVE-2021-47311. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.13.4 and classified as problematic. Affected by this issue is the function free_netdev. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to 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: net: qcom/emac: fix UAF in emac_remove adpt is netdev private data and it cannot be used after free_netdev() call. Using adpt after free_netdev() can cause UAF bug. Fix it by moving free_netdev() at the end of the function.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2021-47311 since 05/21/2024. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 01/21/2025).

The vulnerability scanner Nessus provides a plugin with the ID 214406 (EulerOS 2.0 SP8 : kernel (EulerOS-SA-2025-1123)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.9.277, 4.14.241, 4.19.199, 5.4.135, 5.10.53 or 5.13.5 eliminates this vulnerability. Applying the patch 4d04a42b926e/b1e091331920/11e9d163d631/2b70ca92847c/b560521eca03/8a225a6e07a5/ad297cd2db89 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 Tenable (214406). 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

• 4.9.276
• 4.14.240
• 4.19.198
• 5.4.134
• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.10.36
• 5.10.37
• 5.10.38
• 5.10.39
• 5.10.40
• 5.10.41
• 5.10.42
• 5.10.43
• 5.10.44
• 5.10.45
• 5.10.46
• 5.10.47
• 5.10.48
• 5.10.49
• 5.10.50
• 5.10.51
• 5.10.52
• 5.13.0
• 5.13.1
• 5.13.2
• 5.13.3
• 5.13.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

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

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