Linux Kernel up to 6.1.28/6.2.15/6.3.2 tcp skb_copy_ubufs denial of service

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.1.28/6.2.15/6.3.2 and classified as critical. This affects the function skb_copy_ubufs of the component tcp. The manipulation results in denial of service. This vulnerability is known as CVE-2023-53669. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.1.28/6.2.15/6.3.2. Affected is the function skb_copy_ubufs of the component tcp. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: tcp: fix skb_copy_ubufs() vs BIG TCP David Ahern reported crashes in skb_copy_ubufs() caused by TCP tx zerocopy using hugepages, and skb length bigger than ~68 KB. skb_copy_ubufs() assumed it could copy all payload using up to MAX_SKB_FRAGS order-0 pages. This assumption broke when BIG TCP was able to put up to 512 KB per skb. We did not hit this bug at Google because we use CONFIG_MAX_SKB_FRAGS=45 and limit gso_max_size to 180000. A solution is to use higher order pages if needed. v2: add missing __GFP_COMP, or we leak memory.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2023-53669 since 10/07/2025. Technical details are known, but there is no available exploit.

Upgrading to version 6.1.29, 6.2.16 or 6.3.3 eliminates this vulnerability. Applying the patch 7fa93e39fbb0566019c388a8038a4d58552e0910/3c77a377877acbaf03cd7caa21d3644a5dd16301/9cd62f0ba465cf647c7d8c2ca7b0d99ea0c1328f/7e692df3933628d974acb9f5b334d2b3e885e2a6 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 databases at EUVD (EUVD-2025-31975) and CERT Bund (WID-SEC-2025-2229). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Amazon Linux 2
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• Open Source Linux Kernel
• IBM QRadar SIEM
• Dell NetWorker

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.1.24
• 6.1.25
• 6.1.26
• 6.1.27
• 6.1.28
• 6.2.0
• 6.2.1
• 6.2.2
• 6.2.3
• 6.2.4
• 6.2.5
• 6.2.6
• 6.2.7
• 6.2.8
• 6.2.9
• 6.2.10
• 6.2.11
• 6.2.12
• 6.2.13
• 6.2.14
• 6.2.15
• 6.3.0
• 6.3.1
• 6.3.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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