Linux Kernel up to 5.12.12 udp_lib_lookup race condition

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.12.12. It has been classified as problematic. The affected element is the function udp_lib_lookup. This manipulation causes race condition. This vulnerability is handled as CVE-2021-47248. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 5.12.12 and classified as problematic. Affected by this vulnerability is the function udp_lib_lookup. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: udp: fix race between close() and udp_abort() Kaustubh reported and diagnosed a panic in udp_lib_lookup(). The root cause is udp_abort() racing with close(). Both racing functions acquire the socket lock, but udp{v6}_destroy_sock() release it before performing destructive actions. We can't easily extend the socket lock scope to avoid the race, instead use the SOCK_DEAD flag to prevent udp_abort from doing any action when the critical race happens. Diagnosed-and-tested-by: Kaustubh Pandey <[email protected]>

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2021-47248 since 04/10/2024. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 234484 (SUSE SLES15 Security Update : kernel (SUSE-SU-2025:1263-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.9.274, 4.14.238, 4.19.196, 5.4.128, 5.10.46 or 5.12.13 eliminates this vulnerability. Applying the patch e3c36c773aed/a0882f68f54f/2f73448041bd/5a88477c1c85/8729ec8a2238/65310b0aff86/a8b897c7bcd4 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 (234484). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.9.273
• 4.14.237
• 4.19.195
• 5.4.127
• 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
• 5.12.0
• 5.12.1
• 5.12.2
• 5.12.3
• 5.12.4
• 5.12.5
• 5.12.6
• 5.12.7
• 5.12.8
• 5.12.9
• 5.12.10
• 5.12.11
• 5.12.12

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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